Flexible Path to the Moon: Science, Commerce, and Security at Beyond-LEO Earth Orbits

The following lists illustrate some of the science, commerce, and security activities that can take place at, or that can be enabled by capabilities at, Geosyncronous orbit and other beyond-LEO satellite orbits.

Science

• Deploy, assemble, inspect, and/or service GEO science missions (for example, certain NASA and NOAA satellites observing Earth from GEO)


• Inspect GEO satellites. This could include taking samples of old satellites to assess micrometeorite damage, for example. This type of analysis can also be useful for economic and security purposes.

Commerce

• Deploy, assemble, inspect, and/or service GEO commercial missions (for example, communications satellites)


• Enable commercial providers of satellite assembly or servicing capabilities
• Space tourism - history or engineering tour of current or historical GEO satellites (no touching the exhibits, please)
  
• jump-start capabilities that can be useful for commercial missions for other destinations (for example: fuel depots, satellite deployment, assembly, inspection, and/or servicing nodes, low-cost space access, etc)

Security

• Deploy, assemble, inspect, and/or service GEO security missions (for example, military satellites)


• Observe other nations' satellites


• Jump-start capabilities that can be generally useful for security missions (for example: fuel depots, satellite deployment, assembly, inspection, and/or servicing nodes, low-cost space access, etc)

Flexible Path to the Moon: Science, Commerce, and Security at Earth-Moon Lagrange Points

The following lists illustrate some of the science, commerce, and security activities that can take place at, or that can be enabled by capabilities at, Earth-Moon Lagrange points.

Science

• Deploy, assemble, inspect, or service Lagrange Point science missions (for example, Astrophysics or Heliophysics observatories). These could include Earth-Sun Lagrange Point science observatories assembled or serviced at Earth-Moon Lagrange Points, with the ability to transfer between assembly/servicing and operational Lagrange Points


• Measure solar wind


• Prepare for later science or exploration missions to the lunar surface or deep space (perhaps using exploration assembly or servicing nodes)


• Compare ISS science results to results at Earth-Moon Lagrange Points (for example, considering Earth's magnetosphere)

Commerce

• Encourage development of commercial services that can deploy, assemble, inspect, or service Lagrange Point science missions (for example, Astrophysics or Heliophysics observatories). These could include Earth-Sun Lagrange Point science observatories assembled or serviced at Earth-Moon Lagrange Points, with the ability to transfer between assembly/servicing and operational Lagrange Points. The capabilities developed here could be applied to commercial customers, possibly at other locations


• Encourage the development of commercial services that can assemble exploration missions for the government


• Encourage the development of commercial nodes at Earth-Moon Lagrange Points with the government as a customer

Security

• Jump-start capabilities that can be useful for security missions for other destinations (for example: fuel depots, satellite deployment, assembly, inspection, and/or servicing nodes, low-cost space access, etc)

Flexible Path to the Moon: Science, Commerce, and Security in Lunar Orbit

The following lists illustrate some of the science, commerce, and security activities that can take place in, or that can be enabled by capabilities in, lunar orbit.

Science

• Deploy, assemble, inspect, and/or service robotic lunar science missions


• Contribute to lunar sample return missions


• Deploy, assemble, inspect, and/or service robotic Earth observation missions for "full Earth" measurements


• Use telerobotics for missions at the lunar surface. This can be done from Earth, but lunar orbit may provide some advantages depending on mission details: shorter communications delay (including communications relays), less requirements for communications infrastructure, more direct communications paths at times, simulation of Mars or Venus telerobotics from orbit.


• remote sensing observations from the astronauts' spacecraft


• test missions for operations at more distance locations (for example, Mars or Venus telerobotics, direct remote sensing, sample return, or deploying, assembling, inspecting, or servicing robotic spacecraft)


• jump-start capabilities that can be useful for science missions for other destinations (for example: fuel depots, satellite deployment, assembly, inspection, and/or servicing nodes, low-cost space access, etc)


• prepare for later lunar surface astronaut science missions (for example: exploration mission assembly or servicing infrastructure in lunar orbit)

Commerce

• jump-start capabilities that can be useful for commercial missions for other destinations (for example: fuel depots, satellite deployment, assembly, inspection, and/or servicing nodes, low-cost space access, etc).


• Space tourism at lunar orbit (for example, for lunar views)


• Support of commercial robotics at the lunar surface


• Prepare for later commercial lunar surface missions (for example, exploration assembly/servicing node in lunar orbit)

Security

• jump-start capabilities that can be useful for security missions for other destinations (for example: fuel depots, satellite deployment, assembly, inspection, and/or servicing nodes, low-cost space access, etc)

Flexible Path to the Moon: Cislunar Space

This post continues yesterday's discussion on NASA's cislunar space plans on the Flexible Path to Mars by comparing those plans with those of the Flexible Path to the Moon at the same destinations.

The Flexible Path to the Moon includes three phases:

• establishing a solid foothold in LEO with commercial and international participation as well as technology development while robotic precursors blaze an exploration trail
• moving beyond LEO to cislunar space destinations like GEO, lunar orbit, and Earth-Moon Lagrange points
• returning to the surface of the Moon

Each phase is intended to be self-sustaining, to produce useful economic, science, and security benefits, to develop reusable space infrastructure, and to enable more ambitious steps.

It's natural to concentrate either on the first or the last of the three steps on the Flexible Path to the Moon. The first step, establishing a foothold in LEO while robotic scouts move ahead, is our most immediate concern. In the context of the 2011 NASA budget, the NASA human spaceflight exploration work for the next several years will be entirely devoted to this step, although with a view towards the Augustine Flexible Path to Mars. Most of our near-term decisions center around this first step, so it's no surprise it's of great interest.

It's also natural to emphasize the activity that will take place on the lunar surface. The Moon is an entire world waiting to be explored and developed. Although the activities to be done on the Moon's surface would be quite different from the ones performed during the Apollo missions, Apollo gives us a conceptual framework that allows us to easily imagine what might be done there. Fiction and our experience on Earth fill in the gaps that Apollo leaves out. Not only that, but reaching the Moon is the central destination and ultimate goal of the Flexible Path to the Moon. Right?

Wrong.

In the Augustine Flexible Path to Mars, it is probably fair to say that Mars is the ultimate, central destination. The Flexible Path to Mars is about exploring new places to learn about them while getting closer to exploring and learning about Mars.

In the Flexible Path to the Moon, the Moon is actually not the ultimate, central destination, in spite of the name. The Flexible Path to the Moon is intensely focused on the Earth. It is about exploring and developing LEO, cislunar space, and the Moon for the benefit of people on Earth. This can be illustrated by considering the second step on the path, developing cislunar space.

Apollo 8's lunar flyby wasn't our goal in the 1960's. The Ares rockets weren't intended to allow astronauts to linger at cislunar space destinations or to develop infrastructure there. Even in the Augustine Flexible Path to Mars, the cislunar space destinations are treated as mere stepping stones on the way to adventuresome excursions to more distant destinations like asteroids and Mars moons.

In contrast to the Apollo, Constellation, and Flexible Path to Mars approaches that minimize beyond-LEO cislunar space destinations, the Flexible Path to the Moon treats the work that can be done and the benefits that can be gained at GEO, Earth-Moon Lagrange points, and lunar orbit as the heart of the Flexible Path to the Moon. All of the steps on this path can produce benefits for the taxpayers on Earth, but it is the intense focus on deriving economic, security, science, and other benefits from the cislunar space destinations where the Flexible Path to the Moon contrasts the most with Apollo, Constellation, and the Flexible Path to Mars.

In the Flexible Path to the Moon, cislunar space destinations "between" LEO and the lunar surface are not like the empty airspace between your departure and arrival locations on a plane trip, even though there are no rocky bodies there. These destinations are like unpopulated versions of the American West that the new nation on the Eastern seaboard (LEO in our analogy) looked forward to exploring and developing on the way towards the future great cities on the Pacific ocean (the Moon in our analogy).

In other words, cislunar space is not just a "middle-man" between LEO and the lunar surface. We don't want to skip past this step as quickly as possible on the way to the Moon, because this step not only makes the lunar surface more accessible in the long run, but it also serves the same sort of purpose that the Moon itself serves.

Here are a few observations about the activities that can be done at the cislunar space destinations:

• Reaching these destinations is easier than reaching more distant destinations like NEOs or Mars moons. We can get there affordably and safely with considerably less capability (low-cost commercial operations, new technology, propellant depots, heavy lift, etc) than these more difficult destinations. We can also be more confident that a development effort to reach these destinations will succeed.
• Reaching these destinations helps enable later exploration at the lunar surface.
• Reaching these destinations and spending the considerable time and effort to make the most of these destinations before venturing beyond them helps make later exploration and development at the lunar surface more affordable, achievable, and sustainable, even though it may delay the beginning of these missions.
• Reaching these destinations helps enable later exploration at more distant Flexible Path to Mars destinations (for example, NEOs and Mars orbit), as implied by the Augustine Committee report.
• Reaching these destinations and spending the considerable time and effort to make the most of these destinations before venturing beyond them helps make later exploration at more distant Flexible Path to Mars destinations more affordable, achievable, and sustainable, even though it may delay the beginning of these missions.
• Making the most of these destinations enables a wide variety of commercial space activity. This activity in turn should strengthen the space industrial base, add jobs, and enable more useful services that can be enjoyed by the taxpayer.
• These destinations offer benefits across the spectrum of space science fields: Earth science (assembly/servicing, full-Earth data collection), Heliophysics (observatory assembly/servicing), Astrophysics (observatory assembly/servicing), Planetary Science (lunar telerobotics, lunar sample return, lunar remote sensing from astronaut spacecraft, lunar orbiting satellite assembly/servicing, preparation for astronauts at the lunar surface, test and setup for later planetary science at more distant destinations), and various ISS sciences (similar activities outside LEO).
• The capabilities enabled and encouraged by these destinations (satellite assembly/servicing/inspection, fuel depots, reusable space infrastructure, reusable in-space transportation, etc) are highly useful for national security purposes.
• Many of the activities at these destinations require some sort of space infrastructure like satellite servicing or exploration spacecraft assembly nodes. This may bring visions of multi-decade development efforts to build facilities like the ISS, followed by difficult logistics requirements. This need not be the case. These nodes can be considerably smaller than the ISS, and could be focused on specific tasks. Also, these nodes do not need to be permanently occupied (and given radiation considerations may very well not be), so the logistics requirements could be much easier than those of the ISS.
• These destinations provide an interesting variation on space stations. They are harder to reach than LEO, but they have advantages, too. These destinations don't present a requirement for reboost because of atmospheric drag as the ISS orbit does. They don't have the same sort of space debris problem. Microgravity work would not have to suffer from perturbations due to Earth's imperfectly symmetrical gravity field. Instruments and materials would not suffer the same sort of weathering.

These benefits the cislunar space step are important, but what about the Moon? Even if our reach falls short and we don't get to the lunar surface sustainably during this effort, we will have accomplished much if we develop cislunar space. If we do establish ourselves on the Moon in a long-term sense, our initial efforts will still be centered on the cislunar space destinations, and thus on benefits to the people on Earth. Our mission at the lunar surface is not to do lunar surface science, although we may do some of that. It is not to set up a permanent lunar colony, although our work in this phase may bring us closer to such a colony. Our purpose on the lunar surface is to use the Moon as a force multiplier to increase our productivity at the cislunar space destinations.

This will be done in part through the demands that the lunar surface will place on the cislunar space destinations. Our capabilities and infrastructure at these destinations will need to grow to satisfy the demands of the lunar surface work.

It will also be done through the use of lunar resources. Lunar resources can help make lunar surface work affordable, but they will eventually be needed in cislunar space destinations, too. The initial cislunar assembly, servicing, and depot capabilities will be greatly enhanced through the use of these lunar resources.

The work on the lunar surface benefits the taxpayer on Earth mainly through the improvements this work enables in cislunar space. The lunar surface and cislunar space destinations become mutually supporting in a virtuous circle of sustainable and even expanding commercial, industrial, and science capabilities and infrastructure.

In the long run we may ultimately use lunar resources to make closer (i.e. LEO) or more distant (i.e. NEO, Mars moon, etc.) activities more affordable. The development of these resources may even result in a strong permanent presence on the Moon that ultimately develops its own reasons for being. However, with the Flexible Path to the Moon, this process will start by using lunar resources to address needs in cislunar space, which in turn address needs on Earth.

Flexible Path to the Moon: NASA's Cislunar Space Plans

I'd like to discuss cislunar space destinations like lunar orbit, Earth-Moon Lagrange points, and GEO in the context of the Flexible Path to the Moon. Before doing this, however, it's useful to set the stage by considering NASA's plans for these destinations. NASA's current plans are similar to those in the Flexible Path to the Moon in many respects: a focus on commercial and international participation, strong technology development efforts, many robotic precursors, synergy with NASA's science missions and ISS, an initial focusing phase in LEO, and more. However, although both plans include missions to cislunar space, NASA's plans there are quite different from those of the Flexible Path to the Moon.

The Augustine Committee Final Report (PDF) describes the Flexible Path to Mars. This sequence of missions starts with easier beyond-LEO missions like a lunar fly-by, a lunar orbit mission, and/or an Earth-Moon Lagrange point mission. The report gives the impression that these missions are simply stepping stones towards voyages to more distant destinations with a few productive activities thrown in while we're there. The report does not give a sense of the build-up of space infrastructure or repeated visits there.

Ed Crawley from the Augustine Committee and David Mindell recently released a white paper U.S. Human Spaceflight: The FY11 Budget and the Flexible Path (PDF). This white paper confirms the impression that the Flexible Path to Mars does not have a strong cislunar space emphasis. For example, it notes:

The Augustine report envisioned initial test flights within the Earth-Moon system and then operational flights that include visits to "near earth objects" (NEOs, asteroids and spent comets), Mars flybys, Mars orbital flights and eventually exploration of the lunar and Mars surface.

The cislunar space missions are merely test flights, not operational flights. It also states:

Destinations in the Flexible Path have a logical progression. The Augustine report suggested that astronauts might first test the new systems in Earth–Moon space by traveling to lunar orbit and to the Earth-Moon Lagrange points (where the Earth and Moon’s gravity balance each other). Astronauts will then visit Earth-Sun Lagrange points, NEOs, Mars orbit and that of its moons, demonstrating new capabilities for servicing, repair, and construction along the way. These destinations and their value propositions are outlined in Figure 3.5.2-1 of the Augustine report. Additional destinations possible on the Flexible Path are geosynchronous Earth orbit (another place to demonstrate servicing) and eventually asteroids in the belt or Venus orbit.

Clearly the cislunar space destinations not seen as first-class productive and interesting destinations in their own right.

In the Remarks by the President on Space Exploration in the 21st Century, President Obama said:

Early in the next decade, a set of crewed flights will test and prove the systems required for exploration beyond low Earth orbit. And by 2025, we expect new spacecraft designed for long journeys to allow us to begin the first-ever crewed missions beyond the Moon into deep space. So we’ll start -- we’ll start by sending astronauts to an asteroid for the first time in history. By the mid-2030s, I believe we can send humans to orbit Mars and return them safely to Earth. And a landing on Mars will follow. And I expect to be around to see it.

This statement gives the impression that even though we will be going to beyond-LEO destinations like lunar orbit and/or Earth-Moon Lagrange points, and in all likelihood (one or two of) the even more distant Earth-Sun Lagrange points, we won't really be starting until we send astronauts to an asteroid.

In his prepared statements to the Senate's Committee on Commerce, Science, and Technology, NASA Administrator Bolden described the planned series of steps:

Fundamentally, the exploration of space will be a sequence of deep-space destinations for human missions matched to growing capabilities, progressing step-by-step, beginning with crewed flight tests – perhaps a circumlunar mission -- early next decade of vehicles capable of supporting exploration beyond LEO, a human mission to an asteroid by 2025, and a human mission to orbit Mars and return safely to Earth by the 2030s.

NASA clearly considers the cislunar space destinations to be useful for testing deep space exploration capabilities, which of course they are. However, NASA's cislunar space plans don't go beyond these tests. NASA's focus will be on more distant deep space exploration.

Next we will take a very different look at cislunar space in the Flexible Path to the Moon.

Flexible Path to the Moon and the 2011 NASA Budget: An Option to Start Beyond LEO Missions

The 2011 NASA budget changes I've described so far simply focus some of the budget categories more on destinations along the Flexible Path to the Moon. This allows us send robotic missions to those destinations to prepare for astronauts. It allows us to do in-space demonstrations of technologies to make astronaut missions to those destinations more affordable and capable. It allows us to place assets like serviceable satellites beyond LEO, where later they will be incentives to develop beyond-LEO astronaut capabilities. Meanwhile, the commercial LEO transport and use of the ISS continue as described in the 2011 budget.

Although this allows us to set the stage for later beyond-LEO missions as intended in step 1 of the Flexible Path to the Moon, it doesn't start us on steps 2 or 3. It leaves us without specific plans for astronaut missions to Lunar orbit, Earth-Moon Lagrange points, GEO, and the lunar surface. This causes controversy with the current NASA plan, and the approach I've outlined is similar in this respect, even though these plans replace a program that wouldn't get astronauts beyond LEO for decades.

We need to wait for results of robotic precursors, technology development and demonstrations, commercial partnerships, and international partnerships to fully achieve exploration and development of cislunar space and the lunar surface. These results will allow us to make the right decisions to complete these steps affordably. For this reason, I'm not alarmed by the postponement of exploration missions in the current plan.

However, we don't need robotic precursors to implement basic first-generation "foot-in-the-door" transport of astronauts or cargo from LEO to cislunar space destinations. We have experience with this sort of technology from Apollo, ISS, Shuttle, and numerous satellites. We don't need technology demonstrations to implement basic hardware like sensors, satellite servicing modules, pre-positioned supplies, or infrastructure letting astronauts accomplish a first set of important objectives at these destinations. We have experience with this sort of technology from the ISS, Hubble servicing, remote sensing satellites, and other missions. Budget allowing, we could start to develop some basic systems to reach and use lunar orbit, GEO, and Earth-Moon Lagrange points in the near term, and gradually bring in additional capabilities as the budget, partnerships, and demonstrated technologies allow. Thus, the 2011 NASA budget could optionally be modified to enable a first set of beyond-LEO missions.

If a commercial approach is taken, acknowledging potential beyond-LEO markets like space tourism and satellite servicing, a small initial funding line comparable to the CCDEV commercial crew effort could start the process. When the transition to the new NASA approach is well under way (i.e. we have gotten over the "Constellation Transition" and "Shuttle Slip Contingency" humps in the budget), we will have funds available to begin to develop some initial operational beyond-LEO systems. If the budget isn't increased, this might come from a moderate (perhaps 10 or 20%) cut to some of the other new budget lines. The result would still be several times larger than the $500M COTS commercial cargo incentive.

A mutually advantageous form of international participation could enable additional beyond-LEO capabilities. There could be a mixture of NASA, commercial, and international contributions.

Later, after a set of enabling technologies is developed and demonstrated, the technology lines can be scaled back to a modest long-term level to allow larger-scale operations along the Flexible Path to the Moon.

Flexible Path to the Moon and the 2011 NASA Budget: Adjusting the Space Technology Budget

... while at the Same Time Supporting the Earth Science, Heliophysics, Astrophysics, and Planetary Science Budgets

It's interesting to consider NASA's new Space Technology budget in the context of the Flexible Path to the Moon. The Space Technology budget is meant to be "crosscutting". It's not meant to serve the needs of NASA Exploration, or NASA Science, or the space industry, or other government agencies. Instead, it's meant to serve the needs of all of these U.S. space interests. NASA technology development that isn't specific to one area and its missions falls in the general Space Technology budget.

Satellite and observatory assembly and servicing includes a broad array of crosscutting technologies. These capabilities are applicable to exploration, as they provide one type of justification for astronauts reaching achievable exploration destinations like Lagrange points, GEO, and lunar orbit, all likely locations for this type of servicing and assembly. They are also applicable to all major NASA science areas. Earth observation satellites, Heliophysics observatories, Astrophysics observatories, and remote sensing Planetary Science (e.g.: lunar orbit) probes, for example, could all potentially benefit from astronaut assembly and servicing. Robotic servicing, possibly combined with astronaut servicing, is another variant of this capability. The ISS can benefit from new servicing and assembly capabilities, and can also serve as a platform for demonstrating or even operating new servicing and assembly capabilities. Satellite servicing also has the potential to benefit other U.S. space agencies, commercial space vendors with space assets to service or with the ability to offer satellite servicing, and international partners. This sort of servicing and assembly work is "crosscutting" in many ways, and thus should be featured prominently in NASA's new Space Technology budget. If the Flexible Path to the Moon is taken, satellite and observatory assembly and servicing will take an even more prominent role, since this is one of the main drivers and benefits of reaching early Flexible Path to the Moon destinations like lunar orbit, GEO, and Earth-Moon Lagrange points.

The 2011 budget features special budget lines set aside for "Small Satellite Subsystem Technologies" and "Edison Small Satellite Demonstration Missions". Satellite and observatory assembly and servicing are similar to small satellite technologies in that they are crosscutting, multifaceted, and potentially highly practical technologies that also deserve a significant slice of the Space Technology budget pie, especially if the Flexible Path to the Moon is taken. It might make sense to create special budget lines within Space Technology for satellite servicing and assembly technologies and demonstration missions.

Some satellite servicing capabilities are well understood, and just need to be transferred to new missions on the serviced and servicing sides. It might make sense to use some of the satellite servicing "demonstration" funds to augment mainstream satellite or observatory missions by adding fairly well-understood features that make the satellites easy to service as technology demonstrations. This could benefit relatively near-term NASA Earth science, Astrophysics, Heliophysics, or Planetary Science missions, missions of other U.S. government agencies, or commercial missions like communications satellites. Demonstrations on the servicing side could take place in the near term only if the satellites are in (or can be moved to) orbits that are reachable before operational beyond-LEO missions are ready. More advanced serviceability and servicing capabilities would be handled like any other pre-demonstration Space Technology work.

Another possible way for the Space Technology budget to support the Flexible Path to the Moon is to fund space exploration technology work through the Centennial Challenges prize program. Prizes could be offered for work at destinations on the Flexible Path to the Moon. We already have the private Google Lunar X PRIZE competition as a model for this sort of opportunity. Centennial Challenge prizes that take advantage of, or that dovetail with, the work being done for that private competition might make sense. This could include variations on lunar surface work, lunar orbit work, and many other possibilities that function within the private competition's limitations on government funding for the prize-winning missions. Using services of future winners of the private competition to deploy various Space Technology products should also be considered. (There are also many similar opportunities within the new HSF Robotic Precursor budget line, especially for "Scout" missions). The Space Technology budget has a good opportunity to support crosscutting needs of NASA Exploration along the Flexible Path to the Moon and commercial and other private space organizations.

There are many other ways that the Space Technology budget can support exploration along the Flexible Path to the Moon and support other U.S. space organizations at the same time. One of the benefits of the Flexible Path to the Moon is that its exploration concentrates on destinations that have many "crosscutting" overlapping needs and benefits with other space organizations focused on science, commerce, and operational needs of the government. The Flexible Path to the Moon specifically concentrates a great deal on destinations like GEO that are mainstays of traditional space work, unlike the Flexible Path to Mars, which doesn't mention GEO and which could be interpreted to skip past other near-term destinations as quickly as possible. This attribute of the Flexible Path to the Moon allows for many crosscutting technologies in the Space Technology budget to be applied to exploration along that path while at the same time benefiting other non-exploration space organizations that use the same destinations.

Flexible Path to the Moon and the 2011 NASA Budget: Adjusting the Heavy Lift and Propulsion Technology Budget

We have already seen several examples of how the 2011 NASA budget can be adjusted to support the Flexible Path to the Moon by emphasizing near-term space destinations like lunar orbit and Earth-Moon Lagrange points (the same early destinations that start the Augustine Flexible Path to Mars) as well as longer-term destinations on the lunar surface. We simply focus most of our efforts on the reachable destinations along this path rather than difficult destinations like the Martian surface. The 2011 NASA budget for Heavy Lift and Propulsion is no exception.

Early Flexible Path to the Moon destinations don't need heavy lift, and if we can lower launch costs through something closer to mass production of launchers, and at the same time we can demonstrate technologies like autonomous rendezvous and docking, propellant depots, in-space assembly, ISRU, reusable space-only vehicles, and/or reusable lunar landers, we won't need heavy lift for the lunar surface, either. We shouldn't expect success with all of these technologies, but success with a few should be good enough. Leveraging commercial and international participation should also help us develop affordable and sustainable lunar surface access and development without having to develop an unaffordable heavy lift vehicle like Ares V or its close relatives.

It may make sense to advance some sort of heavy lift capability to add to our bag of tricks, but only if it can be done in a way that is both useful and affordable. We don't need heavy lift, but we can surely benefit from useful and affordable heavy lift. Fortunately, the 2011 NASA budget already takes a useful and affordable approach. It develops an RD-180 class engine made in the U.S. that can be used on a future heavy lift vehicle. Such an engine doesn't require a heavy lift vehicle for its justification; it can be used in other rockets (the Atlas V uses the Russian RD-180). Thus, the budget's heavy lift development approach is inherently useful beyond the HLV. The budget's approach also appears to be affordable, leveraging the existing EELV infrastructure and expertise that will exist and need to be paid for whether or not NASA explores or develops an HLV.

The Flexible Path to the Moon would benefit from propulsion capabilities like the following:

• reusable propulsion for astronaut vehicles to go back and forth between LEO and beyond-LEO cislunar space destinations
• highly efficient (and possibly reusable) propulsion to get cargo from LEO to beyond-LEO cislunar space destinations
• propulsion for (possibly reusable) vehicles to get cargo and/or astronauts to and from the lunar surface

If the Flexible Path to the Moon is taken, propulsion research and demonstrations should concentrate on these crucial areas as a higher priority over propulsion to shorten long deep space missions or propulsion for heavy lift.

Flexible Path to the Moon and the 2011 NASA Budget: Adjusting the Technology Demonstration Budget

The new exploration technology demonstration budget includes a number of in-space demonstrations of new technologies to allow those technologies to be comfortably introduced into later operational missions. Like the robotic precursor missions, these are categorized into a set of larger "flagship" missions and smaller missions. Example technologies identified in the budget include in-orbit propellant transfer and storage, lightweight or inflatable space modules, automated rendezvous and docking, landing technologies, closed-loop life support, ISRU, in-space propulsion, EVAs and servicing, and others. These missions can be done in partnership with commercial or other government agencies.

There are a number of reasons that the next few years are a particularly good time to perform technology demonstrations. The obvious driver is that the Ares-based form of Constellation has failed and is being shut down and the Shuttle has been on a path for retirement for several years, requiring a focus on establishing a foothold in LEO again. Technology demonstrations allow us to make considerably more progress towards exploration than Ares-based Constellation would have made in the same years while much of our attention is necessarily focused on the immediate LEO access problem. Now is also a good time for technology demonstrations because a number of factors give us more opportunities for success with these demonstrations:

• a focused driver and motivator for selecting and prioritizing technology demonstration choices - The Flexible Path to the Moon can provide this focus and motivation.
• a backlog of technologies ready for demonstration
• the near-term availability of the completed, funded, and fully staffed ISS as an in-space technology demonstration platform
• the growing capabilities of the low-cost and responsive small satellite industrial base
• the potential near-term availability of commercial reusable suborbital rockets as technology demonstration platforms
• the near-term availability of robotic HSF precursor missions in the 2011 NASA budget that can serve as technology demonstration platforms
• the potential for near-term incremental improvements in launch vehicle cost, availability, and responsiveness presented by new entries in the space access market, the NASA COTS program, and shared space access industrial base costs enabled in part by NASA's switch to rockets that can be used by multiple users like the EELVs
• the potential near-term availability of commercial space lab platforms like the DragonLab that can serve as technology demonstration platforms
• the availability of commercial space businesses that will likely be interested in partnering with NASA on certain technology demonstrations (e.g.: Bigelow Aerospace and others for inflatable modules, ULA and others for orbital propellant depots) and that will therefore likely be willing to contribute funding and focus to these efforts if they can benefit from the demonstrated technologies
• the potential availability of early Flexible Path to the Moon destinations as technology demonstration locations - if we can squeeze a basic capability to reach these destinations into the 2011 budget

The approach that should be taken with the technology demonstration missions to enable the Flexible Path to the Moon is to focus most of those missions on technologies that are relevant to cislunar space and the lunar surface. This is just a shift in focus; there should still be room to explore technologies relevant to more futuristic missions. Here are a few examples:

Entry, Descent, and Landing Technologies; Autonomous Precision Landing - Focus should be put on demonstrating landing technologies relevant to the Flexible Path to the Moon (precision landing and hazard avoidance on the Moon, landing on Earth following Flexible Path to the Moon missions) rather than on, for example, landing on Mars.

Advanced In-Space Propulsion - Focus should be put on demonstrating in-space propulsion technologies relevant to the Flexible Path to the Moon (lunar lander propulsion, efficient and possibly reusable propulsion for cislunar space transportation) rather than on, for example, propulsion for quickly reaching distant deep space destinations like NEOs and Mars.

Human-Robotic Interactive Systems Demonstrations - Focus should be put on demonstrations relevant to the Flexible Path to the Moon, like cooperative human and robotic satellite servicing or observatory assembly in cislunar space, or telerobotics for robots on the lunar surface.

Extravehicular Activity Demonstrations - Focus should be put on EVA demonstrations relevant to the Flexible Path to the Moon, such as spacesuits usable on the lunar surface, and suits that enable servicing, assembly, and similar work in cislunar space.

You begin to get the idea. If the Flexible Path to the Moon is taken, each type of technology demonstration should be focused mainly on enabling or improving the cislunar and lunar surface destinations along the Flexible Path to the Moon.

The successes and failures of these technology demonstrations will help drive the operational missions on the Flexible Path to the Moon. At the same time, they will still break ground for more distant destinations, since there is room for some deep space technology demonstration work, and since many of the demonstrated technologies have applicability both on and beyond the Flexible Path to the Moon.

Flexible Path to the Moon and the 2011 NASA Budget: Adjusting the Robotic Precursor Mission Budget

NASA's 2011 budget proposal includes a strong line of HSF robotic precursor missions to follow the model of LRO and LCROSS. These precursor missions are intended to blaze a trail for astronauts at various potential HSF destinations like the lunar surface, NEOs, Mars moons, Lagrange points, and Mars. Unlike robotic science missions, these HSF precursor missions will concentrate on identifying hazards and resources of concern to astronauts. Collaboration with NASA Science and non-NASA missions, such has hosting instruments, can also take place.

The budget includes $3B over 5 years for these missions. Two classes of missions are planned: the traditional missions which are expected to cost less than $800M each (typically substantially less), and Scout missions that are expected to cost from $100M to $200M each. It doesn't take much math to realize that in order to do the many jobs required to chart a course for the Flexible Path to the Moon, such as resource assessment, various types of ISRU demonstrations, astronaut site selection, hazard assessment, astronaut site preparation, and others, we will need to concentrate most of these missions on the destinations in the Flexible Path to the Moon. The Moon itself needs to be the primary subject of this series of missions if we're to succeed on the Flexible Path to the Moon. It's worthwhile to spend some effort on later destinations like NEOs, Mars Moons, and Mars, but a "concentration of forces" is needed at the Moon. The same may eventually well be the case at more distant destinations as we begin to accomplish the goals of the Flexible Path to the Moon and turn our gaze to more distant destinations. Indeed, if NASA actually implements the Augustine Flexible Path to Mars as many expect, it should concentrate its precursor missions on the more achievable destinations along that path.

The 2011 NASA robotic precursor budget actually gives the Moon a lot of attention, considering that the Flexible Path to Mars seems to be in favor. The budget starts 2 precursor missions in 2011. One will probably be a lunar surface mission to assess resources and demonstrate telerobotics at the Moon. A second mission could be centered on lunar or asteroid ISRU or NEO/Mars moon landing, so there is a chance that the second mission could go to the Moon, too. Mission starts would continue in later years. The new line of robotic precursor "Scouts" seem to be perfect for small commercial missions like those planned by Google Lunar X PRIZE teams. The Moon would naturally be an appropriate destination for such teams.

Nevertheless, if the Flexible Path to the Moon is taken, an even greater concentration of lunar precursor missions would be needed than is suggested in the 2011 NASA budget. This is just a matter of shifting the distribution of mission destinations within the precursor budget. Even with this shift, the limited funding for precursor robotics and the significant exploration and development ambitions of the Flexible Path to the Moon demand that this line leverages as much as is possible those opportunities offered by commercial space, international partners, and other parts of NASA like Science missions and new technology demonstrations. It is really here in the robotic HSF precursor missions where the Flexible Path to the Moon succeeds or falls short.

Flexible Path to the Moon and the 2011 NASA Budget: Adjusting the Planetary Science Budget

The proposed Planetary Science budget from 2011 to 2015 includes a number of lunar science missions. The Lunar Quest Program funds LADEE (Lunar Atmosphere and Dust Environment Explorer) and the ILN (International Lunar Network). It also funds Lunar Research and Analysis. The LRO (Lunar Reconnaissance Orbiter) now orbiting the Moon is scheduled to be handed over to the Lunar Quest Program later this year. The ILN is currently under review by the Decadal Survey process because of cost reasons. According to Future Planetary Exploration blog, the Decadal Survey is also considering a Lunar Polar Volatiles Lander.

The Discovery Program is managing GRAIL (Gravity Recovery and Interior Laboratory), and one of the 3 finalists for the next New Frontiers mission is MoonRise, a lunar sample return mission.

The Lunar Quest Program has a relatively small budget - not much over $100M per year. That makes sense because this program is focused on small, affordable missions and research. Considering GRAIL, and assuming Moonrise wins New Frontiers and ILN or some mission to replace it is funded, an appropriately strong lunar science program to set the stage for the Flexible Path to the Moon would exist. However, there is no guarantee that this will happen.

Noting that the Mars Exploration science budget is about $500M per year, if the Flexible Path to the Moon is to be implemented, it seems appropriate to considerably increase the Lunar Quest Program budget to allow more small lunar science missions, or to start a separate line of larger lunar science missions. This would ensure a steady series of lunar science missions appropriate for the Flexible Path to the Moon. In the near term, this might come at the expense of other planetary science missions, but the capabilities developed along the Flexible Path to the Moon should in the long run build a strong foundation for more cost-effective and ambitious science missions across the solar system. The short-term effect on other planetary science missions might not be great anyway; GRAIL is already funded and it's possible that MoonRise will be funded too. This change simply ensures that a steady series of lunar science missions is funded to help pave the Flexible Path to the Moon, and to set the stage for more detailed lunar science and development when astronauts eventually reach the lunar surface.

Flexible Path to the Moon and the 2011 NASA Budget: Introduction to Adjusting the Budget

This post begins to consider how to implement the Flexible Path to the Moon largely, but not entirely, within the constraints of the 2011 NASA budget. First, let's consider the first of the 3 steps in the Flexible Path to the Moon. From the original post, the first step is:

Establish a Foothold - The first phase includes developing commercial and international partnerships for the full Flexible Path to the Moon, beginning a long-term program to maintain and fully use the ISS through at least 2020, developing U.S. commercial crew and cargo services to support the ISS, establishing a vigorous technology development program, and starting an ambitious robotic lunar precursor effort for science, resource scouting, engineering tests, and more with NASA, commercial, and international participation. This phase could also include robotic precursors to destinations that are beyond the scope of the Flexible Path to the Moon, like Near Earth Objects and Mars Moons. Given the fairly large number of robotic missions envisioned here in support of the Flexible Path to the Moon, it is likely that there would be fewer outer planets robot missions.

As it turns out, the 2011 NASA budget proposal includes the ISS, commercial crew and cargo, technology development, and robotic precursor elements. In other words, it's a good start for step 1 of the Flexible Path to the Moon. My guess is that the Flexible Path to Mars rather than the Flexible Path to the Moon will be selected, so the focus of the commercial and international partnerships, technology development, and robotic precursors may include more emphasis than the Flexible Path to the Moon would warrant on destinations that come after that path such as NEOs and Mars, but in its general form the 2011 budget matches this first step.

Future posts will look more closely at some of the prominent items in the 2011 NASA budget proposal to see how they could be shaped to better lay the foundation for the Flexible Path to the Moon. These posts will cover Planetary Science, the other NASA Science directorates considered collectively (Earth Science, Heliophysics, and Astrophysics), Space Technology, Technology Demonstration, Heavy Lift and Propulsion Technology, and Robotic Precursor Missions. Finally, I'll present some thoughts on actually starting beyond-LEO missions.

Flexible Path to the Moon and the 2011 NASA Budget: Background

I recently coined the phrase Flexible Path to the Moon for an approach to exploration and development of space by astronauts and robots intended to reach the Moon using gradual, incremental steps that are useful and sustainable. This phrase is based on the Augustine Committee's "Flexible Path to Mars". In fact the Flexible Path to the Moon uses the early destinations of the Augustine Flexible Path to Mars: Earth-Moon Lagrange points and lunar orbit. It also uses various Earth orbits used by satellites will be accessible if these other destinations are accessible. However, the Flexible Path to the Moon takes more time to build infrastructure, establish commerce, gather science data, and develop various operational capabilities at these initial beyond-LEO destinations. As implied by the Augustine Committee, such steps can and ultimately should be a solid foundation for additional exploration at more distant deep space destinations like Earth-Sun Lagrange points, asteroids, and eventually Mars. However, the intent of the Flexible Path to the Moon is to first use that foundation to explore and develop the lunar surface for science, commerce, and security, while at the same time making more distant exploration more achievable through the use of lunar resources.

There are three steps in the Flexible Path to the Moon, with potential overlap between steps. Each step might take a considerable number of years, depending on the available budget. The steps are to establish a foothold in low-Earth orbit that leads to the next steps, to go to beyond low-Earth orbit to lunar orbit, Earth-Moon Lagrange points, and beyond-LEO satellite orbits for immediate practical benefits and to enable later exploration, and finally to reach, explore, and develop the lunar surface.

With the recently-announced 2011 NASA budget proposal, It may be useful to consider how the Flexible Path to the Moon might fit in that proposal. The 2011 NASA budget contains many changes. Very briefly, it cancels the Constellation program intended to support the space station and eventually reach the Moon's surface. It replaces Constellation with human spaceflight precursor robotic missions, a general space technology program, an exploration technology demonstration program, a heavy lift and propulsion effort, a more fully used International Space Station that will be maintained longer and expanded, additional funding for the existing COTS commercial cargo program to account for the more intensely used space station, a program to encourage commercial crew services to the space station, and a considerably expanded Earth observation program.

Although there is some confusion about what the physical destinations will be for the astronaut exploration component of NASA, all indications are that something like the Flexible Path to Mars is planned. Like the Flexible Path to the Moon, this path might include visits to nearby destinations in space as well as the lunar surface. However, it probably would not develop as much infrastructure and capability at these destinations as would the Flexible Path to the Moon. Instead, it would reach more distant deep space destinations before the lunar surface, and would move as quickly as possible to Mars. There is little information yet about what we would do at various destinations. Would the missions be focused on science? Resources? Exploration? No specific exploration hardware or missions have been spelled out. Some details may come soon, and others may have to wait years for results from robotic precursor and technology demonstration missions.

I would argue that the Flexible Path to the Moon is more achievable and affordable than the Flexible Path to Mars, and is also more rewarding. Even though it seems likely that the Flexible Path to the Moon will not be taken, it could be taken, given the decision to do so. The 2011 NASA budget could, with some minor changes in emphasis, begin to implement the Flexible Path to the Moon. That opportunity will be the subject of later posts.

Flexible Path to the Moon

The Review of U.S. Human Spaceflight Plans Committee Final Report presents two main viable exploration plans based on destination. The first is called "Moon First". This plan focuses on missions to the lunar surface. In contrast, the "Flexible Path to Mars" features a variety of more and more ambitious destinations, such as lunar orbit, Lagrange points, Near Earth Objects, Mars orbit, and Mars Moons (with the possibility of lunar surface visits some time after NEOs are reached). These missions are intended to eventually lead to the Martian surface, possibly after both are achieved.

A number of different approaches are described to reach the Moon First and Flexible Path to Mars destinations. However, all of these approaches require a trend to a roughly $3B/year increase in the NASA Human Spaceflight budget. Such a large increase may be difficult to reach, and even more difficult to maintain over many years. Given this difficulty, I would suggest a third series of destinations, the "Flexible Path to the Moon".

The Flexible Path to the Moon is just a new name, not a new idea. The concept can be found in different forms in some of the documents linked here.

Let's suppose we cannot find the budget needed to implement either one of the Augustine Committee approaches on anything like a timely schedule without unacceptable sacrifices in other NASA areas. Instead of ignoring this problem and plowing ahead anyway on one of the two Augustine paths with an expensive heavy lift development effort that cannot be afforded while developing payloads for the vehicle, using the ISS to its fullest, doing needed technology development, and other important jobs, the Flexible Path to the Moon removes or at least postpones the heavy lift development and its expenses. It also delays or sacrifices the more ambitious Flexible Path destinations, such as NEOs and Mars orbit. These destinations can be addressed at a later time when the Flexible Path to the Moon has developed sufficiently that they are in reach. In compensation, the Flexible Path to the Moon focuses on easier and more near-term destinations like LEO, GEO, lunar orbit, and Earth-Moon Lagrange points, and lingers longer at these destinations to make the most of them. These destinations are used for a variety of purposes. Among other things, infrastructure at these destinations is developed to ultimately allow a cost-effective lunar surface astronaut program.

The Flexible Path to the Moon consists of three phases:

1. Establish a Foothold - The first phase includes developing commercial and international partnerships for the full Flexible Path to the Moon, beginning a long-term program to maintain and fully use the ISS through at least 2020, developing U.S. commercial crew and cargo services to support the ISS, establishing a vigorous technology development program, and starting an ambitious robotic lunar precursor effort for science, resource scouting, engineering tests, and more with NASA, commercial, and international participation. This phase could also include robotic precursors to destinations that are beyond the scope of the Flexible Path to the Moon, like Near Earth Objects and Mars Moons. Given the fairly large number of robotic missions envisioned here in support of the Flexible Path to the Moon, it is likely that there would be fewer outer planets robot missions.


2. Go Beyond LEO - The second phase builds on the first, which would largely continue in an operational mode while the second phase begins development. This phase includes astronaut missions to GEO, Earth-Moon Lagrange points, and lunar orbit using the same class of rockets used in the first phase. Astrophysics, Earth Observation, and Heliophysics observatories could be assembled by astronauts and perhaps robotic helpers in appropriate locations as described in this NASA Spaceflight article, but, given cost constraints, the observatories would most likely be considerably smaller than the ones described there. Satellite servicing capabilities, such as satellite refueling, instrument upgrades, and component replacement could be demonstrated at various locations. Lunar orbit could be used for lunar observations and telerobotics, perhaps to demonstrate telerobotics capabilities for mission beyond the scope of the Flexible Path to the Moon. Space transportation from LEO to and from the more distant destinations would be designed to be affordable and most likely reusable. Reusable space infrastructure would be developed to support these efforts, such as satellite assembly and servicing nodes, lunar orbit space stations, and fuel depots. Spacecraft refueling would become operational. Space infrastructure in LEO, such as commercial LEO space stations to team with the ISS efforts, would be encouraged. It should be noted that the destinations described here are similar to those in the early "Flexible Path to Mars". However, in the Flexible Path to the Moon, we are spending much more time at these destinations. Phase 2 could involve many missions over many years. If the budget does not allow all of this to be done at once, it is possible that there would be multiple sub-phases within Phase 2.


3. Return to the Moon - This phase builds on, and maintains, the infrastructure and capabilities developed in the earlier phases. Using commercial access to space, refueling, reusable spacecraft, and space infrastructure nodes in lunar orbit and/or at Earth-Moon Lagrange points, astronauts would already be close to reaching the lunar surface. Lunar robotics would have prepared the way for productive work at the surface. As the budget allows, this phase adds a lunar lander that could be reusable. It also incrementally adds lunar surface capabilities as needed. These capabilities might include surface mobility, a base, or ISRU facilities, depending on the results of the many earlier lunar robotics efforts.

This Flexible Path to the Moon allows us to achieve great synergy between human missions beyond LEO and NASA science, including ISS Science, Earth Observation, Heliophysics, Astrophysics, and Planetary Science. It provides many opportunities for commercial and international participation. Given that most of our existing science, security, and commercial satellite infrastructure is in the locations described here, this approach provides many ways to achieve the original Vision for Space Exploration goals of science, security, and economic benefits.

I would suggest that the Flexible Path to the Moon is more affordable that either the Moon First or Flexible Path to Mars scenarios envisioned by the Augustine Committee. If one is skeptical that the sort of reusable infrastructure not launched by HLVs described here is cheaper than the HLV-based Moon-First approach, then simply discard or postpone phase 3 above. At least you will still be able to accomplish some useful work with the first 2 phases described above, and still get closer to the Moon and Mars, than if an HLV-based Moon-First or Flexible Path to Mars approach is used without the budget to make them possible.