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.