The Vision for Space Exploration: A Brief History (Part 3)

The Exploration Systems Architecture Study – NASA’s chosen way to implement the Vision for Space Exploration

In the second part of my series detailing the history of the Vision for Space Exploration (VSE), Sean O’Keefe had announced that his tenure as NASA Administrator was over and the search had begun for a new administrator.  Despite the best efforts of many within and outside of the agency, the objectives and emphasis of the Vision had begun to drift.  While the original concept and statement of goals had been clear and unambiguous, the VSE was re-invented by some as a Presidential declaration of an Apollo-style program to land humans on Mars.  This deliberate misconstruction had the effect of subtly orienting the strategic direction away from long-term or permanent lunar surface activities toward a simple, minimalist series of “touch-and-go” missions at the Moon.  In such a view, because there would be no significant long-term activities on the lunar surface, there would be no significant permanent cislunar space capability emplaced as a result.  This operational template implied that eventually, when a human Mars mission was conducted, we would launch everything needed for that trip from Earth’s surface.  As most estimates suggested at least one million pounds in LEO was needed for the fully fueled Mars spacecraft, the launch requirements would be formidable indeed.

The incoming NASA Administrator was Michael Griffin, an engineer and manager who had his own ideas about how to implement the VSE.  One of the first things he did after taking office was to terminate the pointless technology “road-mapping” activities and initiate a new architectural design effort, the Exploration Systems Architecture Study (ESAS).  The purpose of the ESAS was to make decisions on how we would execute lunar and martian missions, what launch vehicles would be required, specify the sizes and capabilities of the human CEV and lunar lander, and identify any new technology development needed to support the effort.  Before coming to NASA, Griffin had led a study sponsored by The Planetary Society to look at the architecture of a program for human missions beyond LEO.  That study was notable for its advocacy of a medium-class launcher based around the use of a Shuttle Solid Rocket Booster (SRB) as its first stage.

The final ESAS report was issued in November 2005 and described a two-launch scenario for lunar missions.  One vehicle (Ares I) used the SRB and a cryogenic upper stage to launch an Apollo-type CEV and service module to LEO.  A second launch would be a true heavy lift vehicle (Ares V), carrying an Earth departure stage and the Altair lunar lander.  The two spacecraft would dock in Earth orbit and then depart for the Moon.  Four crew would transfer to the Altair lander, descend to the surface for a mission lasting (initially) about two weeks, leaving the CEV in lunar orbit.  After the surface mission, the crew would rendezvous in lunar orbit with and return to Earth in the CEV, which would then use aerothermal entry and parachute landing on Earth.

This mission profile was very much in the style of Apollo.  All equipment, consumables and propellant would be launched from Earth and the mission would be completely self-contained.  Most components were discarded during the various stages of the mission; only the CEV would return to Earth, similar to the Apollo command module.  The agency began to implement the ESAS architecture, naming the program Constellation (the CEV was to be called Orion, the launch vehicles Ares I and Ares V, and the lunar lander, Altair.)

The ESAS architecture drew criticism from outside the agency, sometimes on specious grounds.  There is no question that it could have been made to work – the issue was, at what cost?  People within the agency defended the architectural choices of the ESAS, arguing that we had to first create the capability to go beyond LEO and then decide what activities were to be undertaken there.

As Marshall McLuhan once said in a different context, in this case, “the medium is the message.” Ostensibly only a plan for a transportation system, the architectural choices made in the ESAS dictated what kind of mission was to be undertaken.  That choice was the traditional spaceflight template of launch, use, discard and repeat.  The ESAS was once famously described as “Apollo on steroids,” a formulation quickly adopted by its critics to denigrate the study, but in fact, a characterization revealing in its verity.  The template of a large heavy lift vehicle sending a small spacecraft to a distant destination for a temporary stay, after which a small piece would return to Earth was the Apollo template.

The “Apollo on steroids” description of Constellation was beyond parody.  It fed the canard that going back to the Moon was pointless because “we’d been there and done that.”  To the extent that no serious thought had been given to what we would be doing on the Moon, such appeared to be a valid criticism.  Lost in the plans for lunar surface activities was any sense of permanence (“the goal of living and working there for increasingly extended periods” as the VSE speech had it) or the creation of new space faring capabilities (“use our time on the Moon to develop and test new approaches and technologies”). These activities were not precluded by the Constellation architecture – they were simply irrelevant to it.  The embarrassment of the agency was that it could not discuss why it was going to the Moon because it had forgotten, had never known in the first place, or had successfully pulled off an end run, changing the mission to an Apollo-type sprint to Mars.  The ESAS had the result of making the VSE subservient to Project Constellation when in fact, the ESAS was supposed to be a way of implementing the VSE.

The real objective of the ESAS architecture was to develop the vehicles needed to conduct a human mission to Mars, one launched and supported wholly from Earth.  Certainly a system that could accomplish such a task could (incidentally) also go to the Moon. The Ares I was not an end unto itself, but merely a clever way to develop the pieces (e.g., five-segment SRB and cryogenic upper stage) needed to make the Ares V.  An Ares V launch vehicle (180 metric tons to LEO) is overkill for a lunar mission, but close to the minimal capability required to launch a chemical propulsion, short-stay mission to Mars (even at that, it would take between 8 and 12 Ares V launches – mostly containing propellant – to support such a mission, making its eventual advent highly uncertain). The logic of the ESAS was that we would get only one chance to develop an entirely new human spaceflight system.  Accepting that premise, it made sense to design to what was perceived to be the long requirement (Mars), one that incidentally met the needs of the intermediate (lunar) one.

The VSE concept of an incremental and sustainable space program had been abandoned. The architecture chosen was an answer to a question that had not been asked.  If the mission was to be one of “go to Mars, like we did to the Moon,” ESAS served the purpose intended.  The retirement of the Shuttle, like Cortez burning his ships, was meant to have left the crew “motivated.”  No President or Congress would ever take the drastic and presumably wildly unpopular step of terminating the human spaceflight program once the Shuttles were gone – would they?

Like most new development programs, Constellation ran into schedule and cost issues.  As the resources required to design and build the new vehicles grew, ancillary activities were gradually cutback and discarded – most notably, the robotic precursor program, originally designed to pave the way for human return to the Moon.  Although a lunar orbital mission (Lunar Reconnaissance Orbiter) flew in 2009, a planned follow-on lander designed to prospect for polar ice and characterize potential landing sites was deferred.  Design modifications to the Shuttle-derived hardware to be used in the future Ares V launch vehicle grew to the point where the Ares V became a completely new development, largely negating the supposed advantages of Shuttle heritage.  As the scope of the Constellation development grew, delivery milestones receded into the future.  Despite these issues, Constellation continued to be supported by both the administration and Congress for four years, although not at the increased funding levels requested, again stretching out the schedule.

Thus, we arrived at the milestone year of 2009, five years after the VSE had been announced.  A new administration took office, one whose ambiguous positions relative to the VSE and the space program in general prior to the election created uncertainty for the future of the program.  Both the identity of the new NASA Administrator and their level of commitment to the goals of the VSE were unknown.  The agency had completed assembly of the ISS and was on track to retire the Shuttle in the following year, but the fate of Constellation was uncertain.  What happened next was unexpected – and beyond belief.  Except that it did, in fact, happen.