The Space Reviewin association with SpaceNews

Shuttle-derived launch vehicles illustration illustration
Developing a new generation of shuttle-derived launch vehicles may force NASA to accelerate the retirement of the shuttle itself. (credit: ATK)

Where do we go from here? Making the Vision for Space Exploration a reality

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How we get there from here: Making the VSE irreversible

It is a reality of life that as Presidential administrations change, so do NASA’s priorities, leaders, and goals. Currently, it appears that the VSE will receive funding and will benefit from NASA leadership that supports its goals at least through the end of the Bush administration in 2009. But what happens beyond then? How do we ensure that the VSE survives the change in administrations?

A phased retirement of the shuttle fleet could be the key to making the VSE irreversible.

Whether the next President is a Republican or a Democrat, it cannot simply be assumed that the VSE will remain a priority under their administration. None of the major expected candidates for president in 2008 have demonstrated strong support for the VSE. (See “2009: a space vision”, The Space Review, July 11, 2005) On the other hand, few have spoken explicitly against it. To be frank, it is simply not on the radar of most national politicians. However, it is a possibility that the next President may see the VSE as a place to save a few million dollars by canceling it. So what can be done by NASA and by Mike Griffin to give the VSE enough momentum so that it can’t be ended on a shortsighted presidential or congressional whim? One possible answer is to retire the shuttle early.

The case for phased retirement

Realistically, it seems very unlikely that any new President would try to keep the shuttle flying as America’s only manned space vehicle indefinitely, especially with the continuing foam problems so publicly highlighted on STS-114, and the new problem of the short-to-medium term loss of the use Michoud Assembly Facility in New Orleans, where the shuttle’s external tanks are built. However, there has been support shown among Democrats for keeping the shuttle flying until the CEV is online, even if a costly recertification is required. The longer the shuttle flies, the greater the potential for another accident, which could very well mean the end of the US manned space program for the foreseeable future. There are two steps that can be taken to ensure that the shuttle is retired and that there is a manned vehicle to replace it once it retires, to at least carry out the first goals of the VSE. First, the development of the CEV needs to be accelerated, which has been done already as described above. Secondly, the shuttle needs to have a firm retirement date. September 30, 2010—the last day of fiscal year 2010—has been set as the official date, but this is after the end of the Bush administration, and the 2009 administration could conceivably change or do away with this date.

However, there has been speculation that the ESAS will contain a recommendation to conduct a phased retirement of the shuttle. This would begin by retiring one orbiter, probably Discovery, the oldest, as early as 2007. Atlantis would probably be retired in 2009, to be followed by the retirement of Endeavour in 2010. A phased retirement could be the key to making the VSE irreversible. While all the orbiters cannot be retired before the 2009 administration comes in, due to ISS obligations, it is certainly possible to retire at least one orbiter at an early date such as 2007. Early retirement of an orbiter will absolutely ensure the retirement of the shuttle fleet by 2010. If a new administration came in during 2009 with only two operational orbiters left, it would not be worth the time and expense to recertify them for flight after 2010 due to the limited operational capabilities of a two-orbiter fleet. If the accelerated development of the CEV was sufficiently far along by that point, it would then be easier, cheaper, and more logical to simply finish building the CEV instead of recertifying only two orbiters for flight. By retiring Discovery in 2007, the shuttle fleet cannot be retained as our only choice for manned US access to space, because an aging two-orbiter fleet will simply not be capable of more than two or three flights per year, and it will not be able to complete the ISS on its own within a reasonable time period, nor would it be able to provide reliable logistics support. Recertifying the orbiters for flight after 2010 would be both extremely costly and also politically inexpedient (at least in today’s climate) due to growing realization of the age of the shuttle, and incidents such as the STS-114 PAL ramp foam loss.

It would be politically impossible (and scientifically, technically, and strategically absurd) to simply end the manned space program, barring another shuttle accident, especially with a well-advanced CEV development program. Therefore, assuming the safe operation of the remaining orbiters, by far the most logical choice for any potential 2009 administration is to support the development and flight of the CEV. This line of reasoning assumes, of course, that CEV development has reached an advanced stage by 2009, which is the reason why accelerated CEV development as planned in the ESAS is vital.

Major work on the LSAM and heavy-lift SDLV are not scheduled to start until 2011, after the Bush administration has left—perhaps the biggest current flaw in the VSE. The SDLV in particular is key to sending crews and their equipment to the Moon. News sources report that NASA has reached an agreement with DoD in which it has received approval to develop the heavy-lift booster, but such plans are always subject to change under new leadership. LSAM and SDLV development should be started under the Bush administration to give additional momentum to the VSE beyond January 2009, and the monies freed by phased retirement could enable this early development to become a reality as well.

Therefore, by conducting a phased retirement of the shuttle and accelerating CEV development, NASA will leave the 2009 administration in a position where it has a new manned space vehicle ready to come online, in parallel with a new booster capable of lifting it to the Moon. In short, all the parts of the lunar mission would already be in hand, or nearly so.

The implementation of a phased retirement becomes even easier if the shuttles are only used to complete the station to the “US Core Complete” configuration, which would require only six to eight more flights. Support for this US Core assembly option has been shown within the Bush administration and in the ESAS. By only using the shuttle to complete the station to US Core Complete and by flying the rest of the station modules on unmanned boosters, NASA could be free to retire an orbiter early as fewer total flights would be needed before the phaseout of the Shuttle program. While retiring Discovery in 2007 would limit the number of possible flights, there would still be enough time to fly the flights required for US Core Complete before 2010 with the remaining two orbiters. Additionally, phased retirement and completion to US Core only would ensure NASA would make as few additional flights as possible with the aging orbiters. This is important because another shuttle accident would almost certainly end the US manned space program, or at the very least cause an extremely lengthy hiatus in human spaceflight by the United States. Additionally, an early shuttle standdown would provide an additional impetus for the development of a new heavy-lift shuttle-derived launch vehicle, for the launch of space station modules after shuttle retirement.

If the United States will be held to its commitment to launch ISS partner nations’ modules—such as Europe’s Columbus and Japan’s Kibo—during a phased retirement, it will be required to develop a new launch vehicle that can launch ISS modules. The easiest and simplest solution to this problem would simply be to use the heavy-lift SDLV, since the ISS modules were developed for launch on the Shuttle system in any case. This SDLV would therefore have reasons to be developed outside of their utility in manned lunar missions, making it less likely (though not impossible) that an administration with lukewarm feelings towards the VSE would cancel (or decline to initiate) the heavy-lift SDLV development if it does not begin before 2011.

Therefore, by conducting a phased retirement of the shuttle and accelerating CEV development, NASA will leave the 2009 administration in a position where it has a new manned space vehicle ready to come online, in parallel with a new booster capable of lifting it to the Moon. In short, all the parts of the lunar mission would already be in hand, or nearly so. The choice is clear: it would be cheaper, and perhaps politically more expedient, for the 2009 administration to simply continue the VSE under these circumstances. Phased retirement of the space shuttle may therefore be the key to supplying the VSE with sufficient momentum for it to become irreversible.


We have come a long way since the Columbia disaster in 2003 and President Bush’s initial announcement of the VSE in 2004. There is still a long way to go and many years to come before it becomes a reality. However, progress has been made since January 2004, and the possible phased retirement of the shuttle may provide the key to providing the VSE with sufficient momentum to make it irreversible. These beginnings may seem small and insignificant, but they are the first small steps toward entering the final frontier and finally, belatedly, taking that giant leap towards making mankind a spacefaring civilization.