Friday, November 27, 2009

Ten Questions for HSF Committee - Question 10

What is the appropriate amount and nature of complementary robotic activities needed to make human space flight activities most productive and affordable over the long term?

A similar question appears in the Augustine Committee charter, but the report doesn't go into much detail to answer it. There are references to robotic activities throughout the report, such as deploying probes, servicing Lagrange point observatories, use of commercial lunar robotics capabilities in human lunar systems, and telerobotics in the Flexible Path. Section 9.6, "Managing the Balance of Human and Robotic Spaceflight", briefly discusses NASA's scientific robotics and budgetary protection for these science missions. However, the closest it comes to clarifying the role for robotics in support of human spaceflight is the following passage:

Needless to say, robotic spaceflight should play an important role in the human spaceflight program itself, reconnoitering scientifically important destinations, surveying future landing sites, providing logistical support and more. Correspondingly, humans can play an important role in science missions, particularly in field geology, exploration, and the maintenance and enhancement of robotic systems in space. (See Figure 9.6-1.) It is in the interest of both science and human spaceflight that a credible and well-rationalized strategy of coordination between the two types of pursuit be developed—without forcing unwarranted intermingling in areas where each would better proceed on its own.

This leaves many questions unanswered:

  • What budget is needed for robotics related to HSF in the report's various options?
  • For each option, what are the required robotic missions, data sets, and capabilities, and what is their schedule?
    What are the enhancing robotic missions for each option?
  • In cases where robotic science and human spaceflight intermingle (probes doing science and HSF resource searches, scientific telerobotics, etc), how should the budget be handled?
  • To what extent should NASA's robotic science missions be directed to support human spaceflight with the report's various options? The answer could be quite different for the Moon First and Flexible Path options.
  • What are the opportunities for commercial and international robotic participation?
  • Is there a valid role for heavy lift with robotics, or would it just absorb robotic mission funding and make robotic missions more expensive and rare?
If, as the report suggests, we can't start astronaut exploration for over a decade, we should pay close attention to exploration we can actually accomplish now: robotic missions. More insight into this critical area would have been useful.

Let's imagine NASA's HSF budget is increased, but not by $3B/year. Some of the difference is made up by commercial and international participation and other cost-saving measures, but there's still a shortfall. We need, but can't afford, certain robotic missions, so the budgetary gaze turns to NASA planetary science. Should planetary science sacrifice missions unrelated to HSF? For example, NASA plans a Jupiter Europa Orbiter (JEO - PDF) that may cost 3 billion dollars or so; this is in conjunction with an ESA Jupiter Ganymede Orbiter (JGO - PDF). Would JEO be replaced with a less costly outer planets contribution, such as instruments or other participation in JGO, or a low-cost Europa mission like Europa Ice Clipper, with the savings devoted to HSF-supporting Moon, NEO, or Mars robotic science? This would not be a case where HSF raids the robotic science budget; a robotic planetary science destination aligned with HSF missions would raid another with top-tier science value but low HSF value. It would be good if the report suggested an approach to deal with or avoid such potential conflicts.

Saturday, November 21, 2009

Ten Questions for HSF Committee - Question 9

Should we reach the end of the Flexible Path as quickly as possible, or should we make the most of each step along that path?

The Augustine report describes the Flexible Path as an incrementally more ambitious and difficult series of deep space missions. The wording of the Flexible Path description seems to indicate that, while exploration capabilities increase gradually on this path, there is little infrastructure built up from mission to mission, and little long-term use of the various deep space destinations. In a sense the deep space missions could be considered "one-offs" that eventually allow us to reach the surface of Mars. For example, the report says

In every flight, the Flexible Path voyages would visit places where humans have never been before, with each mission extending farther than the previous one ...

Clearly, if each mission extends farther than the previous one, we are not lingering at the various destinations.

The report describes several missions to near-Earth objects, but each near-Earth object is a unique destination. The other destinations don't seem to imply or require repeated visits. It is suggested that the Earth-Moon L1 point destination might involve a fuel depot, but no other space infrastructure is implied in the Flexible Path.

I would suggest that the Flexible Path be modified to potentially revisit earlier destinations as appropriate for
  • building space infrastructure such as small habitats or stations, depots, servicing nodes, and assembly areas to enable exploration and resource use

  • additional science benefits such as improved data gathering following analysis of data from earlier Flexible Path missions

  • incremental improvement of engineering and science capabilities at each destination, such as additional observatory servicing capabilities, additional telerobotics missions, and improved science instruments

  • making later exploration steps safer, easier, and more productive through carefully repeated testing of exploration systems at each Flexible Path step and build-up of exploration-enabling space infrastructure

  • more thorough extraction of resources at NEOs if the early NEO ISRU demos show promise

  • enabling commerce and purchasing commercial services at the various destinations
The Flexible Path should specifically spell out options for gradually passing over responsibility for earlier destinations to commercial space without having the space agency completely losing interest in those earlier destinations.

In a limited budget, the adjustment I've described would come at a price. Our journey along the Flexible Path would be slower. That's not a trivial price. However, a slower journey is probably justified if it results in getting more benefits out of each step.

Ten Questions for HSF Committee - Question 8

Should the relative risks and rewards of Ares 1 and commercial alternatives be evaluated?

The Augustine Committee report notes that

If we craft a space architecture to provide opportunities to industry, creating an assured initial market, there is the potential—not without risk—that the eventual costs to the government could be reduced substantially.


While there are many potential benefits of commercial services that transport crew to low-Earth orbit, there are simply too many risks at the present time not to have a viable fallback option for risk mitigation.

These are just examples; the report repeatedly describes commercial transportation services in terms of risk. It goes into some detail on those risks in section 5.3.3, "Commercial Services to Transport Crew to Low-Earth Orbit".

It is undeniably true that there is risk in using the commercial space industry for basic space transportation. However, there is also risk in using the traditional NASA cost-plus contract or in-house development approaches. Is one type of risk greater than the other? If so, which one? Let's use the Ares 1 program as an example. Ares 1 clearly demonstrates that NASA's traditional procurement approach can come with significant, and perhaps overwhelming, budgetary, schedule, political, and management risk. Other similar NASA rocket and human spaceflight programs have also shown that this type of risk is often quite high. The real question is not whether Ares 1 or commercial transportation involve risk, it's how the 2 approaches compare in their level of risk, and how the 2 approaches compare in their level of potential benefits.

One factor to consider when comparing Ares 1 and commercial transport risk is that a commercial approach like the current COTS cargo procurement can include multiple vendors, eliminating the risk of a single point design during development. Of course having multiple independent systems also reduces risk during operation. Consider the multiple years NASA was grounded following the Shuttle accidents, and the long delays during various other Shuttle investigations. Multiple Ares 1 class systems are presumably unaffordable, so Ares 1 by itself presents serious development and operation risk simply due to its being 1 system. The Augustine report imagines 3 commercial vendors, with one falling by the wayside during development. The report accounts for this level of competition in its budget estimates.

Another factor is that the COTS approach shields NASA from much of the budget risk, since NASA only has to pay when milestones are actually met, and since the commercial operators would take responsibility for some of the funding in such an approach. The commercial operators would be willing to take that responsibility in part because their services could be used in other markets beyond LEO crew transport for NASA, giving them an extra incentive to succeed that is not available to Ares 1 contractors.

We should also consider that commercial vendors are already used in areas with much higher stakes than human spaceflight. One example in the space industry is the use of EELV launchers for national security payloads. The issue is not one of government vs. private industry, since NASA already uses private contractors for Ares. As the report describes in detail, NASA would still have a strong safety oversight role when using the services of commercial vendors. The issue is how the government should purchase services from private industry, and how it should form contracts with private industry, in this particular market where technologies have been used for many decades and commercial vendors are eager to develop markets.

Another factor that shouldn't be overlooked is that the commercial vendors would only need to address the challenges of an LEO "taxi" service, and would not need to develop more difficult systems that are also capable of exploration missions.

Given the budget and schedule that we face, all options include risk. Which risk is greater, and is the greater risk worth taking because of greater potential benefits? The report should compare the options side by side.

If there are too many risks with commercial transportation for NASA to not have a viable fallback option for risk mitigation, why would there not be too many risks with Ares 1 transportation for NASA to not have a viable fallback option for risk mitigation? It seems that if a fully independent transportation system or fallback plan for such a system is needed for the commercial approach, such a fallback is also be needed for the Ares 1 approach, unless we come to the conclusion that Ares 1 is much less risky than multiple commercial services. This would truly be an astonishing conclusion, given what we already know about Ares 1 and the history of similar NASA development programs.

If a fallback for Ares 1 is needed, then the costs of Ares 1 have been considerably understated by the Augustine Committee. If the commercial options are to be burdened with an independent non-commercial fallback, all Augustine options using Ares 1 need to add the funding and schedule required for a fully independent crew transportation fallback in case Ares 1 fails.

A human-rated Ares V does not qualify as an independent fallback for Ares 1.

Friday, November 20, 2009

Ten Questions for HSF Committee - Question 7

Should the relative risks and rewards of Heavy lift and refueling be evaluated?

The Augustine Committee report states:

"Using a launch system with more than three critical launches begins to cause unacceptably low mission launch reliability. Therefore a prudent strategy would be to use launch vehicles that allow the completion of a lunar mission with no more than three launches without refueling. This would imply a launch mass to low-Earth orbit of at least 65 to 70 mt based on current NASA lunar plans. Vehicles in the range up to about 100 mt will require in-space refueling for more demanding missions. Vehicle above this launch capability will be enhanced by in-space refueling, but will not require it. When in-space refueling is developed, any of these launchers will become more capable."

Calling this a "prudent strategy" implies that developing in-space refueling is more risky than developing a large heavy lift vehicle. The idea is that with the HLV, we can at least do lunar missions, and more ambitious missions will be the bonus we get if refueling is developed. If we have a really big HLV, maybe we don't need refueling at all. Under inevitable budget pressures, such an outlook will likely result in refueling funds ultimately being diverted to the "critical path" HLV.

Why not look at this the other way around? What type of missions can we accomplish with existing rockets plus refueling? Could we have 3 "layers" of missions: easy missions that only require existing rockets, baseline exploration missions where we need refueling, and a "bonus" set of missions where we need both refueling and heavy lift? Then refueling will be on the critical path, but heavy lift won't. Even without refueling or heavy lift we will still accomplish something.
Of course it wouldn't be prudent to take this approach if refueling is riskier than HLV. However, is this the case?

We already know the Saturn rockets were ended after only a few flights. We already know Ares V development is so expensive that it causes havoc to even a less-constrained budget. Ares V development also causes extreme delays for any exploration that relies on it. This form of heavy lift obviously comes with serious budget and schedule risk, and there is some degree of technical risk as well. Developing, demonstrating, and operating refueling is not without risk, but is it really more risky than heavy lift development and operation? Perhaps the answer is complex, depending on the specific HLV and refueling technologies used.

Let's turn the tables and at least consider a prudent strategy baselining refueling in our exploration plans, while allowing heavy lift to give us greater exploration capabilities should that risky technology arrive.

Risk is not the only factor when deciding whether we should put heavy lift or refueling on the critical path. Potential benefits are also important, and can justify greater risk. For example, if the military has an important security satellite that is needed to defend the nation ready to launch that requires heavy lift, then developing heavy lift would be beneficial because it allows this national security mission to occur. At the moment, I don't see evidence that such benefits are really there for heavy lift, but that could change if some organization other than NASA exploration steps forward with plans and money to use heavy lift. I mentioned some benefits of refueling here; suffice it to say that they appear to be quite compelling both for exploration and for general benefits to the nation.

As an aside, I'm not sure why lunar missions sized by NASA's current plans are used as the baseline in this case. Considering that the exploration budget is a huge issue, why not use some easier destination, such as Earth orbit, Earth-Moon Lagrange points, and lunar orbit, as the baseline, and consider more difficult destinations like lunar surface missions as "bonuses" if refueling and other approaches like reusable landers and reusable spacecraft don't work out? This seems like a more prudent strategy in the case where very ambitious versions of heavy lift appear likely to use far too much of the available budget and schedule. Such as strategy looks even better if we use a smaller HLV that can later be upgraded if needed.

Interestingly, the 65 to 70 mt to LEO threshold discussed above contradicts more modest HLV capabilities described elsewhere in the report as the minimum needed for exploration.

Tuesday, November 17, 2009

Ten Questions for HSF Committee - Question 6

What are the implications of astronaut servicing of Lagrange point observatories?

The Committee outlines “Flexible Path” Lagrange point destinations where one objective is to service deep space observatories. It may make sense, if we actually do go to the trouble to develop astronaut satellite servicing and repair capabilities again, to do so on a larger scale, rather than to go to such trouble just for 1 or 2 Lagrange point satellites. In fact, if such servicing is productive for Lagrange point satellites, it may very well be more productive for Earth-orbiting satellites of comparable value. Earth-orbiting satellites can be easier to reach, and specific servicing procedures could be applied to lines of identical satellites in Earth orbit.

If satellite servicing capabilities are developed for exploration, will they only be used for exploration, or will they be used for Earth-orbiting satellites, too? Is there a role for NASA to encourage widespread commercial satellite servicing by providing an initial market for this type of service, developing standards, or developing technology? These seem to be important questions. Satellite servicing in the context of NASA exploration could be a way for exploration to deliver major benefits to the nation if it results in widespread use of servicing, upgrade, and repair capabilities on nationally-important satellites, and if it results in a thriving commercial space industry developing the serviceable satellites and performing the servicing.

All of this, of course, depends on satellite servicing and repair capabilities being justifiable in an economic sense. Can we improve upon heritage satellite servicing costs enough to make them commercially viable? Some possible improvements might come through:
  • lower-cost launch
  • lower-cost in-space operations
  • servicing multiple satellites per mission
  • performing other useful work during satellite servicing missions
  • using common servicing techniques on multiple identical satellites
  • using permanent "servicing nodes" rather than repeatedly launching and retrieving the same servicing hardware

I don't know if these or other approaches are enough to make satellite servicing worthwhile, but if we do engage in Lagrange point servicing, it would make sense to consider the capability in a broader light.

Can we do satellite servicing safely enough to apply it to dozens of satellites?

There are many variations on how Lagrange point observatory servicing could be done.

The mindset driving servicing may vary:
  • The servicing could be done as a "box to check" in an exploration path that seeks to go farther from Earth. This mindset places a high value on ground-breaking exploration for its own sake.
  • The servicing could be done with the intention to repeatedly service a number of Lagrange point observatories. This mindset places a high value on the satellite servicing capability and/or the satellites being serviced.

Different servicing concepts could result from the two approaches. For example, a more permanent servicing capability may justify long-duration servicing node(s) that may only be occupied occasionally.

The plan for responsibility for the capability can vary:

  • Servicing may be seen as a strictly government responsibility.
  • Servicing may be seen as a government responsibility that is transferred to commercial space to allow government to explore more.
  • Servicing could include commercial participation from the beginning.

The scope of servicing can vary greatly:

  • Servicing could be limited to Lagrange point satellites.
  • Servicing could be developed for Lagrange point satellites as part of an exploration plan, and then these capabilities could be applied to Earth-orbiting satellites.
  • Servicing could be applied to Earth-orbiting satellites with an eye towards later applying it to Lagrange point satellites as part of the exploration plan.

Serviced Earth-orbiting satellites might be owned by NASA, other government agencies, or private industry.

The specific type of servicing and repair could also vary:

  • Servicing could be limited to satellite inspection.
  • Servicing could include refueling.
  • Servicing could include replacement or upgrade of major components such as instruments.
  • Servicing could be done by robots, astronauts, or combinations of robots and astronauts.

The destinations for the astronauts performing Lagrange point servicing can vary:

  • Astronauts could go to Earth-Moon Lagrange points, and service Earth-Sun Lagrange point satellites there (requiring the satellites to move themselves between Lagrange points, or tugs to move them).
  • Astronauts could go to Earth-Sun Lagrange points to service satellites there.

The diversity of destinations for astronauts would become even richer if the capability is applied to the satellites in various Earth orbits.

If it is done in the first place, a great deal of thought should go into how to develop Lagrange point servicing in such a way that similar capabilities become useful in Earth orbit:

  • If tugs are designed to move Earth-Sun Lagrange point observatories to and from Earth-Moon Lagrange points, would this architecture work well if applied in Earth orbit to move satellites to astronauts in LEO?
  • Would an architecture where the observatories and satellites move themselves work well in Earth orbit?
  • Could a Lagrange point servicing node be duplicated in a useful way in Earth orbit for servicing satellites there?
  • Is there any synergy with the exploration refueling capability described by the Augustine Comittee report and the ability to refuel satellites? If so, is there any synergy with the propellant ISRU capability described by the report and refueled satellites?
  • Could commercial satellite servicing in Earth orbit have any synergy with the ISS commercial crew transport services in most of the report's options?
  • Could exploration vehicles or depots be serviced in a similar manner to satellites?

Many similar questions need to be considered.

It is beyond the scope of the Augustine Committee to fully delve into all of the possibilities and decisions surrounding satellite servicing, but it would be useful for the report to point in a direction that helps start the conversation. We may not be able to get astronauts to Lagrange points any time soon, but we should be able to get them to LEO where they could do servicing sooner. We need to think well in advance of actual servicing missions about making observatories serviceable, too.

Saturday, November 14, 2009

Ten Questions for HSF Committee - Question 5

What is the real goal of human space exploration?

The Augustine Committee's report states the following:

A human landing followed by an extended human presence on Mars stands prominently above all other opportunities for exploration. Mars is unquestionably the most scientifically interesting destination in the inner solar system, with a planetary history much like Earth’s. It possesses resources that can be used for life support and propellants. If humans are ever to live for long periods on another planetary surface, it is likely to be on Mars.

However, the Committee also notes that we are far from being able to visit the surface of Mars now. If that's the case, does it make sense to consider Mars to be the "ultimate destination for human exploration"? Does it make sense to make any particular physical location or orbit such an overriding goal or "ultimate destination", and thus perhaps mask more near-term goals that are both important and achievable?

I would argue that the exploration program should not be driven by specific destinations. Independence from preconceived destinations could be an advantage of the Flexible Path if that path weren't chosen mainly as a progression towards the Martian surface. However, the Flexible Path is Mars-centric; in the report it's called a "flexible path to Mars".

Instead of defining an exploration effort by a physical location, it should be defined by goals that address national needs, solve national problems, and delivering national benefits. In fact the report itself includes the following passage centered on national benefits rather than physical locations:

How will we explore to deliver the greatest benefit to the nation? Planning for a human spaceflight program should begin with a choice about its goals—rather than a choice of possible destinations. Destinations should derive from goals, and alternative architectures may be weighed against those goals. There is now a strong consensus in the United States that the next step in human spaceflight is to travel beyond low-Earth orbit. This should carry important benefits to society, including: driving technological innovation; developing commercial industries and important national capabilities; and contributing to our expertise in further exploration. Human exploration can contribute appropriately to the expansion of scientific knowledge, particularly in areas such as field geology, and it is in the interest of both science and human spaceflight that a credible and well-rationalized strategy of coordination between them be developed. Crucially, human spaceflight objectives should broadly align with key national objectives.

If destinations should derive from nationally-important goals, then let's not get ahead of ourselves and pick a specific destination like the surface of Mars as the "ultimate destination for exploration". Let Mars and all of the other destinations fend for themselves in terms of the national benefits we can expect from getting there, and factor in the national costs and risks we can expect in getting there. Maybe Mars will still stand out in such an analysis - but let's do the analysis.

If reaching the surface of Mars is out of reach given the available exploration budget, let's find an exploration path that still delivers national benefits even if it isn't up to the task of reaching Mars. With the Flexible Path, for example, that might mean choosing an affordable approach that is not able to reach even Mars orbit, but that can deliver benefits beyond LEO but closer to Earth through commercial incentives, science, space infrastructure development, and space resource extraction.

Ten Questions for HSF Committee - Question 4

Should Venus orbit be included in the Flexible Path?

Another potential Flexible Path (deep space) destination that was not listed in the Committee's report is Venus orbit. One could argue that Mars orbit is more compelling than Venus orbit because of the Mars moons, unassisted views of the Martian surface from orbit, and greater potential for later astronaut work on that surface. Such an argument could be quite convincing. However, if Mars orbit is reached, it seems that the option to reach Venus orbit could then be considered, at least as a Flexible Path "off-ramp".

Venus orbit allows teleoperation of surface robots just as Mars orbit does. The heat at Venus's surface may make teleoperations even more useful because heat-producing and heat-sensitive electronics on surface robots can be replaced with telecommands. As with Mars, teleoperation may be useful in Venus's atmosphere with robotic planes or balloons. Venus surface or atmosphere sample return may be an option just as it is on Mars. Remote sensing of Venus could take place from orbit. Solar observations are another possibility. At the risk of straying too far into fiction territory, perhaps an astronaut mission in the upper Venusian atmosphere could even be achieved. Venus may also be a compelling destination given the insight it might give on climate processes.

The Flexible Path already has "off-ramps". Why not include Venus orbit as another potential future "off-ramp" - one that at the moment we don't plan to travel?

Ten Questions for HSF Committee - Question 3

Should Earth orbit be included in the Flexible Path?

The Committee outlines a number of Flexible Path (deep space) destinations. However, it does not list Earth orbit. The Committee's charter is framed so that exploration is viewed as activity beyond low-Earth orbit. However, there are Earth orbits beyond LEO that could be useful for satellite servicing, remote sensing, and other purposes. If the subject at hand wasn't beyond-LEO exploration, we could also consider non-traditional orbits for astronauts in LEO, such as sun-synchronous polar orbits for satellite servicing.

Should these Earth orbit destinations be considered in the Flexible Path? Perhaps they could be considered Flexible Path commercial "off-ramps", based on whether or not the commercial space industry is interested in taking over satellite servicing capabilities NASA develops for Flexible Path Lagrange point observatories and applying those capabilities to Earth-orbiting satellites?

Friday, November 13, 2009

Ten Questions for HSF Committee - Question 2

Why wasn't a Phase I EELV HLV or similar HLV included in any options?

Is an affordable heavy lift vehicle possible? The Augustine Committee report’s cheapest heavy lift option is the Phase II EELV HLV, which delivers 75MT to LEO. Since by name this HLV variant is a "Phase II", obviously there is a Phase I. Phase I is a smaller EELV that delivers 40-50MT to LEO, depending on the specific EELV used.

The Committee's final report says

… the EELV-heritage super heavy is still larger than the Committee’s estimated smallest possible launcher to support exploration, which is in the range of 40 to 60 mt.

Thus a 40-50MT Phase I EELV HLV fits within the Committee's estimated smallest possible launcher range to support exploration. Why not simply implement Phase I then, and base exploration plans, or at least initial exploration plans, on that rocket for the larger exploration launches? Surely this would be cheaper and faster to develop than any of the report’s menu of heavy lift vehicles. Phase I is only a portion of Phase II, the cheapest HLV presented by the Committee in its options that don't fit the budget and enable beyond-LEO exploration at the same time.

There are advantages to the Phase I EELV HLV. Phase I would still allow a considerable amount of exploration, especially if combined with refueling, assembly, and docking in space. Although the most difficult and mass-intensive exploration missions may from one perspective be the most interesting and exotic ones, from another perspective the easier missions have a great deal of appeal in terms of economic potential. Perhaps it wouldn't be so bad if the Phase I EELV HLV causes us to dwell a bit longer at those destinations, developing their potential to the fullest.

It also wouldn't be bad if a smaller HLV encourages us to perfect our skills at refueling, ISRU, reusable space-only craft, frequent low-cost launch, docking, and assembly. All of these skills may find productive use outside NASA exploration. Enabling such capabilities may prove to be more important than NASA's actual exploration itself.

Phase I would also be more compatible with existing EELV production lines and infrastructure, and would be sized to have a greater chance than the larger HLVs to address realistic national security, commercial, and science needs outside NASA human spaceflight. I don't see national security, commercial, or science interests rushing to the head of the line with payloads in tow, eagerly waiting for a spot on a 75MT or greater HLV, and willing to pitch in some funding to make sure it happens.

Finally, if some day our exploration ambitions grow beyond Phase I, we could always continue to Phase II.

Ten Questions for HSF Committee - Question 1

Are beyond-LEO exploration and fitting the budget really incompatible?

Two of the goals in the Committee's charter were to fit the budget and to enable beyond-LEO exploration. However, only two of the options presented by the Committee fit the budget, and neither of these options enable beyond-LEO exploration in a meaningful time frame. I will ignore the first of these two options, the budget-constrained Program of Record, since it doesn't keep the ISS, encourage commercial space, or include international participation, violating many of the Committee's goals. It also completes Ares 1 after the ISS is deorbited, leaving it nowhere to go. Finally, it starts lunar exploration far, far in the future.

As the Committee states, the Program of Record "offers little or no apparent value".

The Committee's Option 2 fits the constrained budget while allowing technology development, a longer ISS lifespan, and commercial support of the ISS. It removes Ares 1, but delivers an "Ares V Lite" in the late 2020's, with actual use of the Ares V Lite happening much later. Essentially beyond-LEO exploration is not viable under this plan, either, although some useful non-exploration activity can be expected with Option 2.

Given that this option attempts to fit the constrained budget while enabling beyond-LEO exploration, why was it encumbered with the high development cost and long schedule of Ares V Lite? Why was it required to reach the lunar surface, when the Deep Space (Flexible Path) options depicted elsewhere in the report involve a lower cost of entry? The report states:

In the process of developing these options, the Committee conducted a sensitivity analysis to determine whether any reasonable exploration program (e.g., with different heavylift vehicles, or a different exploration destination) would fit within the FY 2010 budget guidance. The Committee could find none. In addition, the Committee tried to develop a variant of the Flexible Path that fit within the FY 2010 budget, and such a variant looked no more promising than Option 2, with the first missions beyond low-Earth orbit in the late 2020s.

This analysis led the Committee to its finding that human exploration beyond low-Earth orbit is not viable under the FY 2010 budget guideline. It would be possible to continue the ISS and a program of human activity in low-Earth orbit within this budget guidance, and to develop the technology for future exploration, but the budget limitation would delay meaningful exploration well into the 2020s or beyond.

It would be good to see the analysis behind these conclusions. What if only the early Flexible Path destinations such as lunar orbit and Lagrange points were considered? What if, to match these easier destinations, an easier heavy lift option such as the Phase I EELV HLV, or no HLV at all (just refueling and/or assembly) were used? The tradeoffs in terms of reduced cost and shortened schedule versus losing or postponing more difficult destinations should be spelled out.

Such information would be valuable for an Administration that might be considering no budget increase, or perhaps only a modest budget increase, for exploration.

Ten Questions for HSF Committee - Introduction

A while ago I discussed 10 questions I thought the Human Space Flight Plans Committee members should ask their presenters. Now that the Committee's final report (PDF) is in, I'd like to discuss 10 questions I might ask the Committee itself, were I in a policy position where I needed to do so.

Before I start the questions, I'd like to emphasize that I think the Committee's work is important and useful. In some cases my questions are really just that. In other cases I have opinions that contradict parts of the report, which will probably be evident from the questions themselves. However, I agree with most of the report. Just to make it clear that I think it's a good report, since we're dealing in 10's, here are 10 important ways I think the report has it right:

  • The Program of Record is unsustainable, and needs major revisions or total replacement.
  • A strong technology program is vital.
  • Firewalls are needed to protect areas like NASA robotic missions.
  • Abandoning the ISS shortly after it is finished is not viable politically, and there is a lot of useful science and engineering work that can and should be done there for many years. The NASA exploration plan needs to take this into account.
  • Major commercial participation is not only important in its own right, but enables NASA's exploration mission.
  • Major international participation is also a crucial enabler of NASA exploration.
  • Refueling and ISRU are technologies with great potential not only for NASA exploration, but for our entire space industry.
  • Long-range NASA budget plans should factor in likely cost growth.
  • Although a Moon-first approach is viable and in some ways quite attractive if done the right way, a deep space focused exploration plan should be considered.
  • Gap-ending alternatives to Ares can be expected to be ready before Ares 1 could be, although we should treat optimistic schedules for those alternatives with some skepticism just as we do with the Ares 1 schedule.
As with the Vision for Space Exploration and the Aldridge Commission recommendations, the trick will be to turn these results from a report to actual implementation. This will have to be done in the face of political and contractor interests that like the money flowing where and how it is now, regardless of whether or not that is in the broader national interest.

Now, let's get on to the questions. I plan to post these gradually, using the tag below for all of them.

Sunday, October 04, 2009

Thwarting Augustine

A recent Space News article, White House Seeks to Restore Human Spaceflight Funding, includes some thoughts on how NASA should react to the final options of the Human Space Flight Review Plans Committee:

Doug Stanley, the Georgia Institute of Technology engineer who led NASA’s 2005 Exploration Systems Architecture Study that picked Ares 1 and the heavy-lift Ares 5 designs over competing approaches that relied on U.S. Evolved Expendable Launch Vehicles, said that while the Augustine panel’s analysis provides useful budget and policy assessments of options for the future of manned spaceflight, the rapid pace of the review did not allow for a thorough analysis of cost, risk and schedule implications associated with those options.

I'd say the Augustine committee analysis of cost, risk, and schedule is a lot more credible than that of the ESAS. The Augustine committee and ESAS had a similar amount of time to do their work. Unlike ESAS, the Augustine committee is open about its deliberations, allowing independent parties to critique and evaluate its conclusions. Unlike ESAS, it is independent of NASA, and thus is able to make fair evaluations. The Augustine committee members are experienced and diverse, protecting the committee from taking the side of one of the various camps in the space industry, and protecting it from producing uninformed results. Finally, the Augustine committee has shown itself to be responsive to its charter, whereas ESAS completely discarded the most important parts of the Vision for Space Exploration.

I really think we need to do a fairly detailed architecture study as a follow-on to what [the Augustine panel] has done,” Stanley said during a Sept. 28 seminar on the Augustine report at the George Washington University Space Policy Institute here. “The purpose was not to do a detailed architecture study, it was to lay out and look at budget issues and policy issues we’d have to define.

Do we really need another NASA architecture study of the ESAS sort? ESAS ignored the important parts of the Vision for Space Exploration and the recommendations of the Aldridge Commission. Why would we expect a new NASA architecture study to do anything but dismantle the central results of the Augustine Committee, and replace them with something more or less like the current Ares plan? If that happens we should not be surprised if we wind up exactly where we are now, with a new human spaceflight review committee showing us that once again we're in a human spaceflight quagmire.

Such a NASA human spaceflight transportation architecture study isn't needed, since we don't need a NASA human exploration space flight architecture. There is nothing for the study to study. It's clear from the initial summary of the Augustine options that the things we need to do over the next few years are the following, and we won't be able to afford much else:
  1. finish the ISS

  2. extend the ISS

  3. encourage commercial space to develop and operate a crew transportation capability to support the ISS

  4. as currently planned, encourage commercial space to develop and operate a cargo transportation capability to support the ISS

  5. rebuild NASA's research and development capabilities related to human spaceflight

  6. negotiate mutually-beneficial roles for international partners

  7. start an ambitious robotic precursor program to prepare for human exploration (in part to demonstrate significant early progress, since the Augustine options show human exploration missions only happening in the distant future)
Notice the absence of a new operational NASA human spaceflight transportation system. There may be a single new NASA human spaceflight transportation component in the mix, such as something like Orion, but we cannot afford a multi-system NASA transportation architecture.

I will also go a little beyond the Augustine committee analysis, and assume we will not be ramping up NASA's human spaceflight budget to the tune of $3 billion per year. Perhaps NASA will get $1 billion more per year; perhaps NASA will get cut. A major increase does not seem likely given the overall Federal budget situation and current political trends. NASA's performance on Constellation also doesn't make new NASA human spaceflight development efforts particularly attractive to fund. That implies that the expensive heavy lift options presented by the Augustine committee in all of its options are not affordable. Thus we are left with a couple more jobs to start over the next few years:
  1. develop and demonstrate refueling capability

  2. possibly begin developing relatively modest commercial heavy lift capability - but if this is done, keep the risky HLV development off the critical path until it is built

With those ingredients, perhaps we will be ready for a NASA exploration transportation architecture study ... several years from now, when some of the points I've just listed have produced results.

Stanley said before the White and NASA can select a new space transportation architecture, they need to decide whether the shuttle will keep flying beyond 2010, whether the international space station will remain in orbit through 2020, where the United States wants to send its astronauts in the decades ahead, and define a general policy toward commercial and international transport of astronauts.

In other words, one of the Augustine options needs to be selected. That's true.

However, as I described above, we need to do a lot more than that before NASA selects a new space transportation architecture, or we will have the same problem with the Augustine analysis that we had with the Vision for Space Exploration and the Aldridge Commission. Without strong management, which we cannot count on with so many other big issues related to science and technology the Administration is focused on, the NASA space transportation architecture study will, if history is any guide, discard the earlier policies and results and come up with something more suitable to parochial NASA interests.

If any space transportation architecture study is done, such a study needs to be independent of NASA political and management pressure.

Once the White House embraces a direction for U.S. human spaceflight, Stanley said NASA should then be allowed to conduct a thorough architecture study to include apples-to-apples comparisons of the cost, safety and risk of the Augustine panel’s options, as well as alternative scenarios the panel might not have considered.

May I use my cynical filter to translate?

Once the White House embraces one of the Augustine committee options, NASA human spaceflight management should then be allowed to do an "apples-to-apples" comparison of the Augustine committee options, as well as alternative options the panel might not have considered that happen to serve NASA interests really well. They should then be allowed to discard the selected Augustine option, and pick one that benefits certain portions of NASA rather than the people of the United States.

In addition, Stanley urged that NASA be allowed to determine the true cost and risk of commercial crew transport in low Earth orbit.

In other words, NASA should be allowed to ignore the potential of commercial crew transport in low Earth orbit, and instead continue to buy crew transport services from Russia while NASA spends decades and tens of billions of dollars to build a government-designed and government-operated crew transport "business" to compete with U.S. commercial space business, but that does nothing to address national needs like security and commerce.

There is no need for a NASA evaluation of "the true cost and risk of commercial crew transport in low Earth orbit". We already know that such a generic NASA evaluation of "commercial crew transport" is sure to conclude that a NASA-designed and NASA-operated crew transportation system is by far safer, simpler, sooner, better, faster, and cheaper than any imaginable commercial crew transportation. Why even bother with the evaluation when you know its conclusion in advance?

If NASA arranges a crew transportation competition similar to the cargo portion of the original COTS program, NASA will have an opportunity to evaluate the development and operational cost, as well as the risk, of each proposed transport service. The only thing that needs to be done is to select the best ones.

The independent Augustine committee has already reached the same results that the Aldridge Commission and original Vision for Space Exploration did: commercial crew transportation in LEO is essential to human space exploration and the U.S. national interest.

“There is a lot of work that needs to be done,” he said.


Sunday, September 13, 2009

Dr. Griffin on the Augustine Committee - Part 11 of 11

11) Finally, the Commission did not do that which would have been most valuable - rendering a clear-eyed, independent assessment of the progress and status of Constellation with respect to its ability to meet goals which have been established in two successive NASA Authorization Acts ...

Griffin seems to be confused about goals. The Augustine committee doesn't need to concern itself with "goals" that people like Senator Shelby and Griffin himself pushed through a past Congress. The committee needs to concern itself with the goals it was given in its charter: encouraging commercial space, fitting the budget, getting U.S. ISS support online faster than the program of record, getting beyond LEO, balancing operations with R&D as well as precursor and helper robotics, bringing international participation into the picture, and evaluating a longer ISS lifespan. That's what the committee was told to do, and that's what it did. Clearly the program of record fails in every one of these areas except perhaps for getting beyond LEO, so what is there to assess?

If we want to take a step back and assess how the program of record is meeting its goals, look to the Vision for Space Exploration document, which clearly specifies what the goals are for the VSE: exploration designed to deliver economic, security, and science benefits in the context of commercial and international participation. It's spelled out very plainly at the beginning of the document. The program of record just as plainly is failing to do these things, with the exception of some bright spots like LRO/LCROSS (and others). This isn't controversial - the program of record isn't even trying to do these things.

Griffin might assume that the HSF committee would disregard their charter and do something more to their (or his) tastes. Fortunately they did their job.

... followed by an assessment of what would be required to get and keep that program on track. Instead, the Commission sought to formulate new options for new programs...

Again, the Augustine committee charter is to formulate options - and since that's plural and the program of record is only one option, by definition that means at least some of the options will be "new programs". It's in their charter, so it's what they did. If Griffin wants to take issue with the Augustine committee's charter, he should take it up with OSTP, not the Augustine committee. However, I suspect he will have a hard time convincing OSTP that the elements of the charter are inappropriate.

Finally, it's not as if the Augustine committee ignored the program of record. They spent quite a lot of time on it, and it does appear as a baseline reference in their suite of options.

Dr. Griffin on the Augustine Committee - Part 11 o...
Dr. Griffin on the Augustine Committee - Part 10 o...
Dr. Griffin on the Augustine Committee - Part 9 of...
Dr. Griffin on the Augustine Committee - Part 8 of...
Dr. Griffin on the Augustine Committee - Part 7 of...
Dr. Griffin on the Augustine Committee - Part 6 of...
Dr. Griffin on the Augustine Committee - Part 5 of...
Dr. Griffin on the Augustine Committee - Part 4 of...
Dr. Griffin on the Augustine Committee - Part 3 of...
Dr. Griffin on the Augustine Committee - Part 2 of...
Dr. Griffin on the Augustine Committee - Part 1 of...

Dr. Griffin on the Augustine Committee - Part 10 of 11

10) The use of "fuel depots" as recommended in the Summary appears to be a solution in search of a problem.

Fuel depots are a solution to the following problems:
  • providing an on-ramp for commercial space participation (a key VSE goal)

  • providing an on-ramp for international participation (a key VSE goal)

  • providing an incentive to develop low-cost space access (an important secondary VSE goal)

  • through low-cost space access, helping to achieve security, science, and economic benefits (the 3 central VSE goals) by making launch of security, science, and commercial space missions affordable

  • providing a market for lunar ISRU of propellants (an important secondary VSE goal)

  • demonstrating a capability (refueling) that would be useful for military, commercial, and science satellites (again addressing the 3 central VSE goals)

  • allowing the development of a heavy-lift vehicle to be avoided, or a much smaller heavy lift vehicle to be sufficient, making the VSE development more affordable and sustainable (criteria mentioned numerous times in the VSE)

  • allowing in-space vehicles to be refueled, and thus reused

In fact, heavy lift appears to be a solution in search of a problem. Who needs heavy lift? Apparently not NASA science, the communications satellite industry, DOD, intelligence agencies, NOAA, etc. It seems that the main reason NASA would develop heavy lift is to avoid addressing the real goals of the VSE (science, security, and economic benefits in the context of commercial and international participation).

It is difficult to understand how such an approach can offer an economically favorable alternative. The Ares-5 offers the lowest cost-per-pound for payload to orbit of any presently known heavy-lift launch vehicle design. The mass-specific cost of payload to orbit nearly always improves with increasing launch vehicle scale.

Griffin is saying Ares-5 is the cheapest because it's the biggest. That's an absurd law - why not build a rocket 1,000 times bigger at 10,000 times the cost then? The per-kg cost will be miniscule! I think Griffin's law of scale is easily violated when you consider the possibility of smaller, mass-produced rockets. Exploration, with its serious payload mass requirements, could provide the market for such mass-produced rockets.

Griffin's scale rule of thumb also ignores development costs. After all, it will be a long time before those tens of billions of dollars of Ares-5 (and related Ares-1) development efforts are amortized, at a maximum flight rate of 2 per year. We already have the EELVs and are already building Falcon 9 and Taurus 2 anyway, so their development cost for a job like fuel launch for exploration is $0. When you consider Ares-5 costs, you also have to consider the possibility that the development effort will fail, and all development costs will be wasted ... or the development effort will succeed, but the operations will be so expensive that they are canceled as happened with Apollo, and again the development costs will be wasted.

The recommendation in favor of an architectural approach based upon the use of many smaller vehicles to resupply a fuel depot ignores this fact, as well as the fact that a fuel depot requires a presently non-existent technology - the ability to provide closed-cycle refrigeration to maintain cryogenic fuels in the necessary thermodynamic state in space.

That's why we fund NASA research and development, technology demonstration missions like the New Millennium series, and innovation prizes. Well, we used to fund these things before Dr. Griffin diverted those funds to Ares.

This technology is a holy grail of deep-space exploration, because it is necessary for both chemical- and nuclear-powered upper stages.

Ok, let's get to work and develop it then!

To establish an architecture based upon a non-existent technology at the very beginning of beyond-LEO operations is unwise.

Ares-5 is also non-existent technology. No Ares-5 has ever been launched, and none will be for decades at best.

At any rate, why would be need a fully-developed depot technology now to include it in our long-range plans? There is so much for astronauts to do in LEO, GEO, Earth-Moon Lagrange points, and lunar orbit - as well as with robotic precursors at the more difficult destinations for HSF - before we even need to consider using either depots or HLV. We don't need to define *any* specific architecture for jobs like Mars landings at this point. Let's just take some affordable, achievable, and useful steps in the right direction for now. One of those steps is developing and demonstrating refueling technologies so that when we are at the point where we need to decide what the details of the next exploration phase will be, the important and enabling refueling capability will be available.

Dr. Griffin on the Augustine Committee - Part 9 of 11

9) The recommendation in favor of the dual-launch "Ares-5 Lite" approach as the baseline for lunar missions is difficult to understand. ... Because of the economies of scale inherent to the design of launch vehicles, such a vehicle should be designed to lift as large a payload as possible within the constraints of the facilities and infrastructure available to build and transport it. This provides the greatest marginal improvement in capability at the lowest marginal cost.

I don't have much to say about Ares 5 vs Ares 5 Lite. Neither option looks good to me. I can understand why the committee would look into Ares 5 Lite rather than Ares 5, simply because a single vehicle smaller than the larger of the Ares 1/Ares 5 pair is liable to be faster, easier and cheaper to develop. Let's face it - like it or not, development cost, schedule, and risk are the make-it-or-break-it issues at hand, not getting the greatest marginal improvement in capability at the lowest marginal cost during operation.

Griffin's approach of designing the biggest launcher possible ignores the tremendous cost and time penalty of doing the development. Simply put, Ares 5 may be too expensive to build, even if it is cheaper than Ares 5 Lite on a pound per pound basis. It also ignores the costs to maintain separate infrastructure for both Ares 1 and Ares 5.

Griffin's approach does not consider the benefits of a steady pace of frequent launches to lower marginal cost by spreading fixed costs over more launches, and by encouraging rocket construction that more closely resembles assembly line operations, and perhaps rocket operations that more closely resemble airline operations. Ares 5 would only launch a couple times per year, so it would certainly not benefit from these economic forces. A 2-launch Ares 5 Lite would benefit a bit more from the steady pace of launching the same rocket, but other alternatives could benefit from this force even more.

The real problem with Ares 5 is that it does not contribute to the real goal, which is not to deliver as much mass as possible to the lunar surface per year, per launch, or per dollar, but rather to lower the cost of U.S. launchers in the classes relevant to commercial space, security, and robotic science missions. Such an achievement can be the contribution of the VSE's launch component to the specific, fundamental VSE goal of "security, economic, and science" benefits. If serious commercial, security, and/or science interests step forward with requirements for Ares 5 or Ares 5 Lite launch, then of course we would be justified in taking another look at these rockets. As it is, Ares 5 and Ares 5 Lite don't contribute to the real goal of the VSE.

... All parties agree that a heavy-lift launcher is needed for any human space program beyond LEO. ...

The Augustine committee may support one sort of heavy-lift launcher or another, but I don't agree with them (or Griffin) in this case. First of all, most human space program architectures I've seen that seek to establish infrastructure and do work in GEO, Earth-Moon Lagrange points, and lunar orbit don't include a heavy-lift launcher at all. Typically they involve 1-3 launches of EELV-class payloads to establish some sort of space infrastructure (a servicing node, small space station, depot, etc), and 1-2 launches of EELV-class payloads to get astronauts to LEO and then to the destination (perhaps on an in-space only vehicle). It should be clear that these destinations - GEO, Earth-Moon Lagrange points, and lunar orbit - are all "human space programs beyond LEO". It should also be clear that there is plenty of useful work to do there, such as satellite servicing in GEO, satellite servicing at Earth-Moon Lagrange points (perhaps of Earth-Sun Lagrange point observatories that move themselves or are tugged between these points and the Earth-Moon points), lunar observations from lunar orbit, lunar telerobotics, and build-up of space infrastructure in these orbits and regions to enable greater exploration later.

None of this needs to involve either heavy lift or refueling.

Note that these missions are the type that are most likely to be achievable in anything like the near term, so these are the ones we should be planning for the most, and spending most of our attention on. Surface missions to Mars using 6 or 7 Ares 5 launches and an Ares 1 launch (as presented by NASA to the Augustine Committee) are so distant in time, and so absurd in their per-mission cost using available technology and infrastructure, that we shouldn't be concerned with developing a specific architecture or launch vehicle for them at all yet.

So, I disagree with the statement "a heavy-lift launcher is needed for any human space program beyond LEO."

By the time NASA has become proficient in GEO, lunar orbit, and Earth-Moon Lagrange missions, and it ready to pass these missions on the commercial space, refueling technology could have been demonstrated. With this capability, more destinations are within reach. Still no heavy-lift launcher is needed.

If refueling is not to your taste, add a much milder heavy-lift upgrade, such as a "Phase 1" EELV upgrade to the 40-50MT class, or a similar-sized giant SpaceX Falcon. This is considerably less powerful than the Augustine committee's smallest HLV, the "Phase 2" EELV 75MT class launcher. The development cost and risk should be correspondingly smaller. This class of "mini-HLV" is all that we should need by the time we achieve what we can in GEO, lunar orbit, and Earth-Moon Lagrange points, which will be a long time from now. The "Phase 1" EELV HLV in combination with the appropriate reusable space infrastructure and space assembly would allow us to achieve plenty.

There could come a time after this when a larger HLV is desired - but that time is so far off that we needn't concern ourselves with it. By then, the HLV question should be in the hands of the commercial space market anyway.

Dr. Griffin on the Augustine Committee - Part 8 of 11

8) "Technical problems" with Ares-1 are cited several times, without any acknowledgement that (a) knowledgeable observers in NASA would disagree strongly as to the severity of such problems, and (b) Constellation's "technical problems" are on display because actual work is being accomplished, whereas other options have no problems because no work is being done.

Ares 1 certainly has technical problems. Maybe NASA could fix the problems, maybe not. The fixes may come at the cost of schedule, cost, capability, or safety. They may force another go-around with Orion and Ares 1 design changes affecting each other in a viscous circle. Or ... we may discover in a few years that the fixes turned out to not be so bad. I'll let the Augustine committee take on these issues with input from NASA and the Aerospace Corporation. It's good to have an independent, arms-length assessment outside of NASA, since a NASA presentation of its own problems is by definition not objective. This is why we have auditors and similar independent assessments all the time throughout government and industry.

If Griffin is upset that the Augustine committee is skeptical about Ares 1 technical, schedule, and budget issues, he should take comfort that they are equally skeptical about the schedules presented by United Launch Alliance, SpaceX, and advocates of certain non-Ares HLV ideas.

I would also note that some NASA Constellation employees have quit, and spoken out against Ares. There is also the Direct team, which its public spokespeople claim includes NASA Constellation employees, to at least consider.

At any rate, the severity of Ares 1 technical problems is a bit besides the point. The real issues go back to the Augustine Committee charter, as well as the goals of the VSE. How do we help encourage commercial space? Certainly not with the non-commercial Ares 1. How do we fit the budget? Certainly not with Ares 1, which is expensive to develop and will be expensive to operate. How do we get ISS support online sooner than the program of record? Certainly not with Ares 1, which started with a goal of 2012 operational capability, and 4 years later has in effect slipped ~6 years to 2017-2019 according to the Augustine committee.

Dr. Griffin on the Augustine Committee - Part 7 of 11

7) The Commission is disingenuous when it claims that safety "is not discussed in extensive detail because any concepts falling short in human safety have simply been eliminated from consideration." Similarly, the Commission was "unconvinced that enough is known about any of the potential high-reliability launcher-plus-capsule systems to distinguish their levels of safety in a meaningful way." For the Commission to dismiss out of hand the extensive analytical work that has been done to assure that Constellation systems represent the safest reasonable approach in comparison to all other presently known systems is simply unacceptable. ...

From "A Commercially Based Lunar Architecture" - Zegler, Kutter, and Barr (United Launch Alliance):

Despite the best engineering design and analysis activities it is amply clear that even highly vetted designs such as the Space Shuttle can fail catastrophically. Probabilistic analyses are spectacularly flawed in that they make sweeping assumptions about failure modes and the means to prevent them. Nature relentlessly renders these complex analyses moot when we find another hidden failure mode via flight experience. Ground testing can assure a baseline level of confidence but only extensive flight experience can truly generate a safe vehicle with high confidence in its overall reliability. Aircraft flight testing relies implicitly on this principle.

Extensive flight experience will be hard to come by with Ares 1, which only has the job of launching astronauts for NASA. Commercial rockets like Delta IV, Atlas V, and Falcon 9 have many other jobs, so they can demonstrate their safety and reliability over many launches - or fail to demonstrate that safety and reliability without astronauts on board.

Some critics point out that even if Ares 1 itself is safer than some other rocket, it may make the overall mission more dangerous (for example by causing redundancy to be removed from Orion).

Considering that safety isn't just about launch, the Augustine committee has an interesting idea with the "Deep Space"/"Flexible Path" options. These options postpone Moon and Mars surface exploration, allowing us to postpone the safety issues of landing astronauts on the surface, surface operations, and surface departure. This allows us to grapple with a perhaps more manageable safety problem, that of deep-space operations, for the time being. When we have gotten good at that, we may find the isolated problems related to surface missions to be more manageable, too. Incremental development in hardware and operations may lead to safer missions.

Dr. Griffin on the Augustine Committee - Part 6 of 11

6) The preference for "commercial" options for cargo and, worse, crew delivery to low Earth orbit appears throughout the Summary, together with the statement that "it is an appropriate time to consider turning this transport service over to the commercial sector." What commercial sector? At present, the only clearly available "commercial" option is Ariane 5.

This is false. Dr. Griffin must be aware that there is a huge commercial space sector in the communication satellite field, among others. He must know of the Atlas V rocket. He must have heard of the Delta IV rocket. These rockets already exist. The government support for these rockets is irrelevant to the issue at hand, which is using commercial rockets in the sense that they are run and operated by private businesses, and thus are available to address other markets at the same time they address NASA's needs.

Griffin must also know of the Falcon 9 and Taurus II rockets that will be used in the COTS cargo program that Griffin, to his credit, supported. These rockets have not been proven yet, but they are far ahead of Ares I and Ares V.

Launching a redesigned Orion crew vehicle is a valid choice in the context of an international program if - and only if - the U.S. is willing to give up independent access to low Earth orbit, a decision imbued with enormous future consequences.

The U.S. already gave up independent access to low Earth orbit, a decision that was imbued with enormous future consequences that we are now facing. This happened when Dr. Griffin chose the Ares I plan, and didn't fund a commercial crew transportation effort to go along with it. This loss of independent access to low Earth orbit is expected to last until 2017 to 2019 if Ares I is the only approach used.

Anyway, even setting that point aside, we could, but don't have to, launch a crew vehicle on a foreign rocket. Why does Griffin suggest that's what we'd have to do if we used commercial transportation services?

... a domestic commercial space transportation sector ... does not presently exist and will not exist in the near future; i.e., substantially prior to the likely completion dates for Ares-1/Orion, if they were properly funded.

It is interesting that Dr. Griffin can predict this with such confidence. I suppose it's possible he will turn out to be right, at least for orbital crew transportation (he is already wrong for other commercial space services), if NASA doesn't properly fund a commercial crew effort.

... If no USG option to deliver cargo and crew to LEO is to be developed following the retirement of the Space Shuttle, the U.S. risks the failure to sustain and utilize a unique facility with a sunk cost of $55 billion on the U.S. side, and nearly $20 billion of international partner investment in addition.

Why is Dr. Griffin so concerned about the ISS when he got rid of most of the ISS science and non-assembly engineering?

Why is he so concerned about the ISS when his exploration plan requires the ISS to be abandoned in 2016? If the commercial COTS cargo services do not get built, Griffin's plan already leaves us with no ability to get cargo and crew to the ISS until 2017-2019, after the ISS is abandoned! Even if the ISS is kept until 2020, and funding appears out of the blue to both support ISS and develop Ares I/Orion at a "brisk" pace, having Ares I/Orion in, say, 2018 does not make that much a difference. Plus, let's be clear: keeping that schedule is highly unlikely given the funding needs of the ISS.

The Russian Soyuz and Progress systems, even if we are willing to pay whatever is required to use them in the interim, simply do not provide sufficient capability to utilize ISS as was intended, and in any case represent a single point failure in regard to such utilization. To hold the support and utilization of the ISS hostage to the emergence of a commercial space sector is not "risky", it is irresponsible.

What is Dr. Griffin's point? We already have this single point of failure in Griffin's current plan, since Ares I/Orion arrive so late!

Also, what is his "hostage" concern? Why does he use loaded words and phrases like "hostage" and the committee "failed to"? Why does he put quotes around words like independent, commercial, fuel depots, and technical problems?

The plan isn't for NASA to stand back and hope a commercial space sector emerges. It's to sufficiently fund commercial crew transportation, at perhaps $2.5B for development from NASA, and more from the vendors, to make sure the commercial space sector emerges. With the commercial vendors pitching in their own money, why would this approach be less likely to succeed than NASA giving contractors money to build Ares I/Orion? The commercial vendors won't want to waste their money, so they'll be even more motivated to succeed. Also, there will be more than 1 commercial competitor if the COTS cargo model is used, so we will no longer have a single point of failure at all.

The Augustine Committee's independent judgment is that commercial vendors will in fact bring ISS crew transportation services to the ISS before Ares I/Orion could, even though Ares I/Orion have had a 4-year head start. This is presumably because of the potential use of existing rockets and other hardware, commercial skin in the game, commercial focus on the ISS transportation job (instead of that and the Moon and Mars), and possible use of near-term COTS cargo hardware.

Also note that the Augustine committee recommends addition money for COTS cargo to make extra sure that effort comes in on schedule.

Also note that in Dr. Griffin's plan, if COTS cargo didn't pan out, and Ares 1/Orion did pan out, and Ares 1/Orion somehow became operational much earlier than they are now expected to, they would use just about all of their funding to supply the ISS. There would be no beyond-LEO exploration even in this scenario that is supremely optimistic for government systems and supremely pessimistic for commercial systems.

If Dr. Griffin really wanted to have both Ares 1/Orion and a secure ISS, he should have funded a COTS crew transportation effort alongside Ares 1/Orion when he had a chance.

As a side issue, I will also note that when Dr. Griffin paints the stark picture of the ISS supplied only by Soyuz and Progress, he is ignoring the European ATV that was already demonstrated and the Japanese HTV that was just launched. We have numerous cargo options, so it seems to make sense to fund a COTS crew effort if we're doing that for COTS cargo.

The Augustine Committee has the job of identifying ways to stimulate the commercial space sector. It isn't surprising that they endorse commercial crew and cargo transportation services, since those also help address other concerns in their charter at the same time (expediting ISS support, fitting the budget, and enabling exploration). However, there are many other legitimate services and ways for NASA to encourage commercial space: data purchases, innovation prizes, more ISS cargo services, lunar surface vehicles, suborbital RLVs, hosted payloads, fuel delivery, and many more. My personal preference would have been to focus NASA's initial use of commercial services on non-crewed areas: lunar robots, cargo delivery, fuel delivery, data purchases and various other satellite services, uncrewed suborbital RLVs, etc. Only later would I have carefully ventured into crew transportation services. However, Dr. Griffin's plan has boxed us into a corner so we really don't have a choice in the matter -- or rather the choice we are faced with is either commercial crew transportation, or no crew transportation.

Dr. Griffin on the Augustine Committee - Part 5 of 11

5) "Independent" cost estimates for Constellation systems are cited. There is no acknowledgement that these are low-fidelity estimates developed over a matter of weeks, yet are offered as corrections to NASA's cost estimates, which have years of effort behind them. ...

I'm not sure why Dr. Griffin surrounds the word Independent with quotes. The Aerospace Corporation is independent of NASA. Therefore, its cost estimates aren't as subject to optimistic thinking or internal pressure and censorship as NASA estimates of its own costs. Note that other independent sources (for example, see The Budgetary Implications of NASA’s Current Plans for Space Exploration by the Congressional Budget Office) have also been skeptical of NASA-only cost estimates. This skepticism is based on a long history of budget overruns on NASA programs. Here's a recent quote in the Kansas City Star on the NASA Science side of the house:

As for the scientific missions, "We're really blowing it on our cost estimates," said Marc Allen, a planning manager in the space agency's Science Mission Directorate. "Everybody's motivated to paint a rosy picture."

Could this be the case within Constellation too? Let's have an independent assessment to find out.

Dr. Griffin on the Augustine Committee - Part 4 of 11

4) Numerous options are presented which are not linked by common goals or a strategy to reach such goals. Instead, differing options are presented to reach differing goals, rendering it impossible to develop meaningful cost/schedule/performance/risk comparisons across them. These options possess vastly differing levels of maturity, yet are offered as if all were on an equally mature footing in regard to their level of technical, cost, schedule, and risk assessment. This is not the case.

It is the Augustine Committee's job to provide a number of options. These options are linked by common goals - the objectives outlined in the committee's charter. The physical destinations are not the goals. In spite of what Dr. Griffin says, it is possible to compare the various options, even though it's true (as the Augustine Committee did point out in their deliberations) that they have varying levels of detail.

Dr. Griffin on the Augustine Committee - Part 3 of 11

3) ... While it is certainly true that Bush Administration budgets did not show any funding for ISS past 2015, it was always quite clear that the decision to cancel or fund the ISS in 2016 and beyond was never within the purview of the Bush Administration to make. ... The fact that some $3+ billion per year will be required to sustain ISS operations past 2015 is, and has always been, a glaring omission in future budget projections. ...

This lack of funding for ISS budget projections past 2015 is a real issue. This is a real concern for the international partners and potential U.S. ISS users, suppliers, and so on. The Augustine Committee had to address this issue because it's in their charter. In fact, they did include extending ISS to 2020 in all of their serious options, as Griffin suggests they do, so I'm not sure why he's objecting.

The problem is that Griffin's exploration plan falls apart after 2016 if that money is shifted to support the ISS. Why didn't he structure an exploration program that could handle this? If he couldn't, why didn't he raise an alarm? It is an amazing and irresponsible thing to develop an exploration plan that assumes that the ISS will be deorbited in 2016, when you expect that won't happen. Where did Griffin think the $3+ billion per year was going to magically come from? Why would a future administration not just cancel the then 10 year old Constellation program, given the discretionary nature of that program, when presented with this discontinuity?

In spite of what Griffin suggests, this is not just a strawman. If the Augustine Committee exposes this issue and gets it resolved one way or another, so there is no doubt in anyone's mind about what the ISS plan is, it will have done a great service.

Dr. Griffin on the Augustine Committee - Part 2 of 11

2) Since NASA's budget as outlined in 2005 was hardly one of rampant growth (only a slight increase above inflation was projected even then), and since the Commission did not report any evidence of substandard execution of the Program of Record - Constellation - one wonders why the Commission failed to recommend as its favored option that of simply restoring the funding necessary to do the job that has, since 2005, been codified in two strongly bi-partisan Congressional Authorization Acts. ...

I imagine that the Augustine Committee failed to recommend (or succeeded in not recommending) keeping Constellation as-is with a funding boost because the committee's charter includes the following objectives:

  • expediting a new U.S. capability to support utilization of the International Space Station (ISS) - Constellation does not do this.
  • stimulating commercial space flight capability - Constellation does not do this.
  • fitting within the current budget profile for NASA exploration activities - Constellation does not do this.
  • appropriate amount of research and development and complementary robotic activities needed to make human space flight activities most productive and affordable over the long term - Constellation does not have this.
  • appropriate opportunities for international collaboration - Constellation does not have this.
  • options for extending ISS operations beyond 2016 - Constellation does not allow this.

How could the Augustine Committee possibly prefer the program of record when the POR does almost none of the things the committee is for?

What does this have to do with the rate of growth of NASA's 2005 budget? Nothing. That budget is now history.

What does this have to do with the level of substandard execution of the POR? Nothing.

No matter what the rate of growth in NASA's 2005 budget, and no matter how good or bad the execution of the POR is, if Constellation doesn't address the items on the Augustine Committee charter (and it doesn't), how could the committee recommend the program of record as its favored option?

Dr. Griffin on the Augustine Committee - Part 1 of 11

As should come as no surprise, former NASA Administrator Griffin has some issues with the preliminary report issued by the Human Space Flight Plans Committee (the new Augustine Committee). In the spirit of Spinal Tap, he has decided to "take it over the cliff" to 11. He has sent out 11 comments on the Augustine Committee's work. I think Dr. Griffin did some good work as NASA Administrator (for example, getting the Shuttle safely back to work, COTS cargo, etc), so I don't want to make it seem like I disagree with everything he did or does. However, I do have some things to say about his 11 comments, so here's part 1 of an 11-part series. Dr. Griffin's comments are the numbered ones in itallics.

1) It is clarifying to see a formal recognition by the Commission that, based upon budgetary considerations, "the human spaceflight program appears to be on an unsustainable trajectory". Given that the Constellation program was designed in accordance with the budget profile specified in 2005, yet has since suffered some $30 billion of reductions to the amount allocated to human lunar return (including almost $12 billion in just the last five fiscal years) this is an unsurprising conclusion, but one which provides the necessary grounding for all subsequent discussions.

When the Vision for Space Exploration (VSE) was formulated, it was known that there would be budgetary ups and downs (with an emphasis on the downs, for anyone trying to be realistic and prudent) during the many years of development for this vision. That's why the VSE was intended to be a "pay-as-you-go" effort. That's why the words "sustainable" and "affordable" appear so many times in the VSE document. The current NASA effort based on the Ares rockets is not sustainable, as the Augustine Committee makes clear.

Dr. Griffin should wonder why Constellation isn't getting such a lofty budget. Could it be that the "Apollo on Steroids" approach isn't attractive to the public or to the space industry? Could it be that the cost and schedule overruns made the Bush and Obama administrations wary of Constellation promises? Could it be that numerous other parts of NASA had their budgets cut during the Griffin years, and now priorities have changed and they are getting back some of the money that went to Constellation? Could it be that Constellation doesn't address the purpose of the VSE? The purpose is not "human lunar return", but rather "to advance U.S. scientific, security, and economic interests through a robust space exploration program" in the context of "international and commercial participation". Constellation isn't doing any of that, so why give it a lot of funding?

Also, be careful when adding up the Constellation budget cuts. The human spaceflight budget is just a place marker while the direction of this effort is evaluated. In addition, look at changes in what is considered "Cross-Agency Support" compared to the original VSE budget.

Finally, if Griffin agrees that Constellation is on an unsustainable trajectory, why didn't he do anything about it? This didn't just start in the last few months. Why didn't he set up a program that could adjust to budget realities, or change the program when budget realities could not longer be fantasized away? If he couldn't fix the problem, why didn't he raise an alarm?

Thursday, July 30, 2009

Griffin Statement to Human Spaceflight Commission

Recently, former NASA Administrator Mike Griffin sent a statement to the Human Space Flight Plans Committee (see Statement by Michael Griffin to The Augustine Committee). Rather than try to help the committee achieve its objectives, Dr. Griffin chose to defend the status quo of the Constellation program. Since the committee's objectives concern improvements over the status quo, Dr. Griffin's comments thus completely miss the point.

Did Dr. Griffin give advice that attempts to expedite a new U.S. capability to support use of the ISS? No, he chose to defend the current Constellation situation. By definition, the current situation cannot deliver a capability faster than itself. In fact, he attacked an approach that might achieve this HSF objective. Did he give advice on fitting within the current budget profile for NASA exploration? No, he actually asked for more money. Did he suggest ways to stimulate commercial spaceflight? In fact he launched an attach on one promising area of commercial spaceflight. Did he suggest ways to make human spaceflight activities more productive through robotic activities or research and development? No. Did he give insight into how to extend ISS support beyond 2016? No. Did he describe a role for a mutually beneficial sort of international participation in exploration? No. Did he have a plan that is more safe, innovative, sustainable, and affordable than the current one? No.

In fact, the only HSF objective that Dr. Griffin addressed is "missions to the Moon and beyond". Recent suggestions that the Constellation approach will cost incredible amounts of money to develop, incredible amounts of money per mission to operate, and perhaps will not be ready for lunar missions until 2028 or 2035 do not make the Constellation approach without modifications seem attractive even for that particular objective.

Having described some of what Dr. Griffin did not write, it seems fair to evaluate some of what he did write:

As I write this, NASA and the Constellation Program are the targets of broad but shallow criticism.

This is an interesting use of language. The word "shallow" could be taken 2 ways - as an addition to "broad" in describing the structure of the criticism, or suggesting that the criticisms are not "deep" or substantial. It would be best to address the criticisms themselves rather than paint them with such a big brush.

At any rate, one wonders why the Constellation program is the subject of such broad criticism. Griffin would probably suggest that the criticism comes from "parochial interests". In fact the interests are no more, and are perhaps less, parochial than Constellation interests. ISS science, commercial space, aeronautics, Earth observation, robotic space science, grass-roots space activism of various sorts, NASA research and development, various national-level interests such those related to defense, security, energy, environment, education, and economics that could potentially benefit from different exploration approaches, and various others all oppose Constellation.

This is because the consensus reached within the last administration and by two prior Congresses as to what the broad objectives of the nation's civil space program should be, is not fully embraced by all members of the space community.

It is true that a consensus was reached about the broad objectives of the nation's civil space program. That consensus was represented by the Vision for Space Exploration and the related Aldridge Commission recommendations. However, as I have noted before, the current Constellation approach is completely different from the Vision for Space Exploration. It is also completely different from the Aldridge Commission recommendations. Supporters of the Vision for Space Exploration and Aldridge Commission recommendations are often opposed to the current Constellation approach for this reason.

Despite what some have said, Constellation is a carefully designed architecture put forth in response to a statement of broad civil space policy objectives by the last administration, which objectives were strongly supported in a hard-won consensus by two successive Congresses.

Again, Constellation in its current form does not address the broad civil space policy objectives defined by the last administration in the Vision for Space Exploration document. Follow the above links and read the Vision for Space Exploration and Aldridge Commission documents yourself. You will find that I only identified some of the points where Constellation doesn't follow this vision in the posts linked above.

How much this former administration policy matters now, with a new administration, remains to be seen.

I, and those at NASA who are responsible for its initial design, subsequent refinement, and present day execution, consider Constellation to be the most expeditiously attainable, broadly capable, lowest risk, and lowest life cycle cost design of which we know to meet those policy objectives, from among the many, many options we considered.

Once again, just read the original documents, and make your own assessment how well Constellation meets the policy objectives described there.

Taken at the rawest level, the Vision for Space Exploration's objectives are to implement an exploration program that supports the nation's economic, security, and science interests. How well does Constellation do that?

I would also note that many of the NASA managers that Dr. Griffin mentions were actually put in place by Dr. Griffin, and took part in Constellation's implementation so far. It's no surprise if they support Constellation. The NASA managers implementing the Vision for Space Exploration before Dr. Griffin became Administrator may have quite a different perspective on Constellation.

If the goals and objectives of our nation's civil space policy should change, or if the detailed engineering analysis which leads to the conclusions I offered above is found to be incorrect or incomplete, then of course Constellation can, and possibly should, be changed. But one must be cautious in such assessments. As I recently offered in another venue, your viewgraphs will always look better than my hardware.

There is no Ares I or Ares V rocket flying. There are alternate rockets, such as the EELVs, with a history of actual launches. Pointing out the contrast between viewgraphs and hardware does Constellation no favors.

In fact, I would go so far as to say that if NASA were receiving today the budgetary allocation that was stipulated when the Vision for Exploration was announced in January, 2004, this Commission would not exist.

It's impossible to prove this one way or the other, but I would make a case against it. Consider what the objectives of the Human Space Flight Plans Committee are. They are to bring an ISS support capability on board sooner, stimulate commercial space, make an exploration plan to the Moon and beyond, fit within the current exploration budget, and consider additional changes such as international participation, complimentary robotics, R&D, and longer ISS support. Suppose that Constellation got the originally expected funding, and then suppose that funding brought Ares 1/Orion ISS capability a bit closer in time. That wouldn't change most of the objectives of the committee one way or the other. Perhaps the ISS support objective would not be as critical as it now is, but consider that Ares I/Orion ISS support is now possibly delayed to 2017 or later. Even if it were 2016 or 2015, it would be too late.

Also consider that most of the Ares I/Orion budget problems are attributed to cost overruns, not budget shortfalls, real as those budget shortfalls are.

Finally, consider the political opposition if Constellation got this hypothetical funding at the expense of other NASA areas.

At any rate, the Vision for Space Exploration was supposed to work on a "pay as you go" basis. It was not supposed to crumble given budget changes, which any manager should have expected over the course of such a long-term program. The components of the Constellation approach are too interdependent. A budget shortfall or technical problem in 1 area has too many ripple effects in the rest of the program.

Present budgets are adequate to allow us to continue human spaceflight operations in low Earth orbit (LEO), but not much more. If policymakers do not wish to spend more, then we should stop talking about larger goals. As I write this, the most recent presidential budget request contains language supporting human lunar return by 2020, but that goal is unattainable with the funding allocated in the request.

Human lunar return by 2020 is unattainable given the current budget and Constellation, but that doesn't mean that 2020 is unattainable by any means. Of course we may have essentially lost 4 years, so 2020 will now be much more difficult.

Consider how difficult the Constellation approach has made it to achieve human lunar return by 2020. Constellation to a large extent fails to include U.S. commercial space as a partner in the main transportation effort. It doesn't include international participation. It doesn't include existing rockets. It doesn't include new, innovative approaches enabled by research and development. It increases political opposition from the science community and the public by delivering only a limited lunar robotic precursor program, and leaves questions related to long-term human lunar stays unanswered the same way. In its original form it required 6 ISS crew capability to the ISS per mission, and 4 to the Moon, when 3 and 2 would have been much easier to achieve. With such difficulties deliberately taken on, it is no surprise that Constellation cannot reach the Moon by 2020 without an unrealistic amount of funding.

It is my considered judgment that the capability for independent and assured human access to space is strategic for the United States. ... With that said, it follows that it cannot be left solely to the discretion and ability of private entities, whose interests can never, and should never, be wholly aligned with those of government, to provide such capability.

This is an amazing statement by Dr. Griffin. Let's first consider whether or not human access to space is strategic. ICBMs are strategic. Robotic military and intelligence satellites, delivering Earth observations, communications, and GPS services to military and intelligence services, are strategic assets. To the extent that they compliment and support the technologies and industries of these military and intelligence capabilities, similar NASA robotic capabilities could be considered to be somewhat strategic. The same goes for similar commercial space satellites. EELV launchers could be considered to be strategically important. Space capabilities that protect the country from natural disasters, or that enable the economy, could be considered to be strategic.

However, it is difficult to imagine how NASA human access to space, as currently done, could be considered to be strategic. NASA human access to space using Constellation hardware, with its high costs, would be no more strategic. It would be too expensive to mount military missions, develop a strong space economy, make operationally responsive space a reality, or to bring about similar changes using Constellation that could transform NASA human spaceflight to the strategic category.

Yet it is possible for commercial space to make human spaceflight strategically useful. A well-developed commercial space infrastructure could deliver strategic benefits. Operationally responsive space is possible with commercial human spaceflight. A lunar economy that delivers important resources could be strategically useful. Commercial suborbital RLVs could cross the strategic threshold. The commercial approach might deliver the cost savings that allow this. With this being a possibility, why does Dr. Griffin rule out commercial human spaceflight?

Let's assume, however, that human spaceflight is in fact already strategically important. Even if this is true, why rule out commercial human spaceflight? Does the military require its own rockets to launch its satellites? No. It supports and uses the EELVs. What makes human spaceflight any different from this? Is NASA human spaceflight as currently done more strategically important than the ability to launch military and intelligence satellites? What about NASA's own COTS program? How is cargo delivery any less strategic than crew transport? For the ISS, without the cargo, there is no crew. There are other examples similar to these where the government relies on commercial capabilities for vital functions.

What about the intelligence agencies? Yes, they use their own assets, but they also support and use DigitalGlobe and GeoEye. The military uses commercial communications satellites on a regular basis. This brings up the hybrid case that Dr. Griffin doesn't mention, where the government human transport capability is pursued, but at the same time the government encourages commercial participants to also meet its needs. The major example in our context is the unfunded COTS-D crew transportation incentive. Why doesn't Dr. Griffin advocate Constellation, but at the same time, make a push for COTS-D or something similar? Why is C0nstellation so much more important than everything else?

Finally, let's grant Dr. Griffin's proposal that human spaceflight, and government human spaceflight in particular, is essential. If that's the case, why did he pick an approach that is so difficult to implement, and that leaves such a long human spaceflight gap? Refer again to the Constellation 6/4 crew requirement, for example.

Interestingly, the Vision for Space Exploration and the Aldridge Commission were much more supportive of commercial space. In fact, they considered thorough commercial space participation to be essential for the success of the Vision for Space Exploration. In particular, the VSE states: NASA does not plan to develop new launch vehicle capabilities except where critical NASA needs—such as heavy lift—are not met by commercial or military systems. ... Pursue commercial opportunities for providing transportation and other services supporting the International Space Station and exploration missions beyond low Earth orbit ... Acquire crew transportation to and from the International Space Station, as required, after the Space Shuttle is retired from service ...

Much of the remainder of Dr. Griffin's statement concerns the first destination of the human spaceflight exploration effort, and in particular switching to a "Mars first" sequence. I don't disagree with Dr. Griffin in this respect, as I consider a "Moon first" sequence to make a lot of sense, as long as it isn't simply "flags and footprints" or "sorties" again. I will note, however, that some of the "Mars-centric" approaches that Dr. Griffin criticizes actually include many earlier and useful steps in space (rather than on planetary or lunar surfaces), and thus are not quite as easily dismissed as he seems to indicate.

One version of this approach the committee is considering is the "Flexible Path"; another is the Planetary Society Roadmap. If done in the spirit of the Vision for Space Exploration (i.e. addressing economics, security, science, and other national priorities, centered around commercial and international participation, including substantial robotic efforts, and driven by research, development, and innovation), this type of approach could fulfill the goals of that vision considerably better than NASA's current Constellation approach, in spite of the different initial destination.