December 12, 2008
There’s a huge hubbub in the press revolving around alleged “obstructionism” at NASA toward the Presidential Transition team. As this rather overwrought piece at the Orlando Sentinel has been posted and commented upon endlessly at several web sites, I do not propose to rehash it. Instead, I want to comment on a theme that I see running through many of the reader comments, viz., that the Vision for Space Exploration (VSE) is dead, that it was a stupid idea to begin with, and the Constellation project (NASA’s Shuttle-replacement spacecraft system) will be and should be terminated.
As I have discussed previously, the VSE was an attempt to give a long-term strategic direction to our national space program after the tragic loss of Space Shuttle Columbia in 2003. It called for the return of Shuttle to flight, completion of the International Space Station, retirement of the Shuttle, development of a new manned spacecraft, a return to the Moon and finally, human missions to Mars and other destinations. Unlike President Kennedy’s Apollo challenge to reach the Moon “before this decade is out”, the motivation for the VSE was to create a long-term, continuing commitment to human spaceflight. Toward that end, it specified what we were to do beyond low Earth orbit – to understand and use the resources of space to create new spacefaring capability. Such an expansion of capability was the purpose for making the use of local resources a principal activity of lunar return in the original Presidential speech.
Many people have conflated the Vision with NASA’s implementation of it, but they are two very different things. Project Constellation is the architecture that NASA has chosen to implement the VSE. In its essentials, Constellation is a launch system, a spacecraft, and a mission design. NASA chose to develop a new series of launch vehicles, the Ares I and V rockets, the Orion crew “capsule” (formerly called the CEV), and a craft designed to land on the Moon, the Altair lunar lander. The mission design is to launch the crew in the Orion capsule on an Ares I into low Earth orbit, launch the Altair lander and rocket departure stage separately on the Ares V, rendezvous and dock with the lander and depart from Earth orbit to the Moon. The crew would land and explore the Moon from the Altair spacecraft, return to the Orion in lunar orbit, and return to Earth in that vehicle.
Much of the criticism of NASA in recent years is actually criticism of this architectural plan, not necessarily of the goals of the Vision (although some have questioned it). But this architecture is an implementation of the VSE; it is not the VSE itself. The Vision specified long-range goals and objectives, not the means to attain them. To briefly review, we are going to the Moon to learn the skills and develop the technologies needed to live and work productively on other worlds. And there are many ways to skin that cat.
NASA spent many months and thousands of man-hours developing the architecture to implement the Vision. From the start, it was controversial, particularly the decision to develop a new launch vehicle (Ares I) using a single Shuttle solid rocket booster, whose sole purpose is to transport the crew vehicle to low Earth orbit. Note well: this vehicle cannot send people to the Moon. Ares I can only transport the crew in Orion to low Earth orbit. To go to the Moon, a second launch of a much larger rocket (Ares V) is required, carrying the lunar lander and an Earth departure stage. Critics allege that by developing Ares I, we are not moving towards the Moon, but rather creating an Earth to LEO system that is less capable than the existing Shuttle. The true objective of the Ares I program is not to build such a vehicle but rather to develop the pieces needed for the big rocket, the Ares V. These pieces include the 5-segment solid rocket motor, cryogenic upper departure stage, and flight avionics, all of which are needed to build the Ares V, which is capable of launching a lunar spacecraft.
One can criticize this architecture on a number of grounds, ranging from the technical to the programmatic, but it is important to distinguish the Constellation program from the Vision for Space Exploration. They are two separate and unequal things. Regardless of what happens to this architecture in the coming months of uncertainty, the VSE remains a logical and forward-looking set of strategic space goals for the nation.
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