Paul D. Spudis
The Once & Future Moon
Smithsonian Air & Space
By moving forward on their mission to convert the U.S. fleet of Space Shuttles into museum pieces, the administration has shifted NASA into neutral. America’s multi-billion dollar investment in the International Space Station (ISS) and our access to space is in jeopardy. As a result of the termination of the Shuttle program, we have no means to assure ISS health and safety or the continuation of manned-space for the coming decade.
True, the “retirement” of the Shuttle is an event long-planned — announced in 2004 as part of the Vision for Space Exploration (VSE). But contrary to common belief, the VSE plan to retire Shuttle was not because it is “too dangerous to fly” or “outdated technology.” Rather, its retirement was intended to free up that portion of the NASA budget it consumes, with that money going to the development of new space vehicles for human missions beyond low Earth orbit—the limit of Shuttle’s reach. In 2004, it was understood that the old and new systems would not seamlessly overlap in time, but in the past eight years, the “gap” of time between the last flight of the Shuttle and the first flight of whatever system succeeds it has increased alarmingly from months to years and now finally, to infinity. The spaceflight “gap,” once seen as risky, now looms before us a black hole of uncertainty.
Our country is set to eliminate the one proven system remaining under our control that can access both space and the ISS. The only thing clear about the administration’s current plan is the confusion surrounding it. Initially, the proposal was to replace a government-built and operated space transportation system with a contractor-controlled one. Coined “New Space,” these contractors were to provide access to orbit for both cargo and people. The New Space path was already being pursued under VSE – not as an immediate replacement for a government system but as an interim adjunct to it. The belief and hope of the agency under VSE was that a transition period would allow commercial companies to design, build and perfect their systems into operational status, while working through anticipated difficulties in technology, budget and program set-backs. As NASA began transitioning away from ISS re-supply, workforce continuity would remain as we began building systems for missions beyond low Earth orbit.
New Space advocates claim that as “commercial” entities, they can provide the needed capabilities to service ISS faster and at a fraction of the cost of either Shuttle or a new government system. If this promise sounds familiar, it is because thirty years ago, as part of the marketing for Shuttle, we heard similar arguments. What we learned then was that spaceflight is difficult, unforgiving and expensive. While one could argue that Shuttle is an inherently flawed transportation system, it still is a working system and it works because we expended the time, experience and money needed to make it work.
Any of the new systems (“commercial” or government) will not have the unique capabilities of Shuttle. Unlike the current “capsule” configuration of the new planned spacecraft, Shuttle carries crew (7 people) and cargo, the latter in enormous quantity – over 24,000 kg per flight. The Russian Soyuz crew (3 people) or Progress cargo vehicles (2350 kg) deliver but a fraction of this so-called “up mass” (the amount of material delivered to the ISS) per launch. The large payload capacity of Shuttle was necessary to build the ISS. Now that Station is complete, one might argue that smaller amounts of cargo delivery are adequate to maintain it. This might be true for normal operations but what happens if a catastrophic failure occurs? The largest part that can be sent to Station will be less than ¼ the mass that Shuttle can deliver. An example of a possible critical need would be a de-orbit motor. If the ISS became uninhabitable or suffered a failure, its orbit would begin to decay. In order to keep over one million pounds of debris from re-entering Earth’s atmosphere, breaking up and falling onto that part of the globe where 98% of humanity resides, a rocket engine must be delivered and attached to send the ISS on a controlled descent into uninhabited areas over the oceans.
Beyond the safety issue surrounding the loss of Shuttle’s capability to deliver to LEO, Shuttle is also an operational service platform when on-orbit. It has an airlock, permitting crew to conduct EVA to repair and maintain ISS and other spacecraft on a routine basis. The only way crew can EVA from the Shuttle’s successor will be to depressurize the entire vehicle, a complex and dangerous maneuver that will likely be conducted only in the event of an emergency. The large stable base of the Shuttle (100 tons on-orbit) permits it to have a robotic operating arm to use both in conjunction with space-walking astronauts and independently. Balky space satellites and parts are firmly held in its cargo bay while repairs are safely completed. Astronauts attempting to service small-mass, free flying satellites find that they drift away, rotating at the slightest touch. The Shuttle serves as a “hangar” in space in which repairs and maintenance can be safely and efficiently accomplished.
Ignoring these considerations is troubling, but might be less so if there were any evidence that serious thought had been given to them. Under our previous direction, it was fully understood that a Shuttle replacement system would be in the pipeline and by now (a bit late and after the usual developmental problems) would have been cutting metal. In contrast, we now have nothing but policy chaos. Summary cancellation of the Constellation rocket system may have been justified on grounds of cost, but the wishful thinking represented by its imaginary replacement is simply unconscionable. Despite the loud and persistent claims of many in the space media, “commercial” providers are not going to produce anywhere near the same capability that Shuttle gives us, even if, through some miracle, they are successful in both budget and schedule. Yet, in the coming decade, essentially the same amount of spending is proposed.
New Space, for all its marketing and eager supporters, has entered a realm where their success on the time frame and budget envisioned – that will greatly affect us all—is uncertain. For a country in troubled times, it is foolhardy, short-sighted and financially ignorant to destroy the one working space access system we have. For New Space cheerleaders to herald the new path as a wonderful anomaly in a sea of otherwise benighted government meddling is to be blind to the reality of the current climate and of the importance of the job they have been handed. The “New Space” companies that NASA currently funds will have the same problems of money, time and architecture that space projects traditionally have had. How long will our rapidly growing government (with its rapidly shrinking discretionary budget) patiently support “commercial” New Space efforts?
In the past, we were assured of government’s ability to project power and protect national interests in space. After the last Shuttle flies, NASA will idle in neutral for the indefinite future. Our space program is adrift—a barometer of our national condition. Sometimes events dictate a course correction. Now is not the time to stop flying Shuttle.