Here‘s a book for your late summer beach reading: Achieving the Vision for Space Exploration on Time and Within Budget. Well technically it’s not really a book, it’s more of a book sized report. Achieving the Vision is written by a group of rocket scientists who think that NASA‘s efforts to build the next generation of manned (or more accurately crewed) space vehicles has gone seriously off the rails.
The story behind Achieving the Vision centers around NASA’s efforts to come up with a replacement for the space shuttle. The plan is to create a couple of new, specialized, rockets: The first will be a smaller people-moving booster and capsule combination similar to the old Apollo setup. The second, larger and unmanned rocket would be used for lofting the heavy bits of hardware, the kind of gear that you might need to go to the Moon and Mars. Both of these new rockets will be largely based on shuttle technology: For example, the people mover will use a stretch version of the shuttle solid rocket booster for a first stage, while the second stage of the cargo booster is pretty clearly derived from the shuttle external fuel tank. The hope is that this new pair of rockets will loft the people and stuff without killing the former and incinerating the latter with disturbing regularity.
What hasn‘t gotten a whole lot of play in the news is the fact that there is a vocal minority of rocket scientists who think that the current NASA plan is going seriously wrong. Achieving the Vision is the work of these dissenters who contend that two new rockets is one too many; they want a single design with variations for different missions. The folks behind Achieving the Vision also argue that while the current NASA designs are based on the shuttle, they are not based on it enough. The dissenters think that the next generation of NASA rockets should be directly derived from the shuttle: Let’s not build a rocket that uses shuttle technology, let’s build a rocket that uses shuttle parts.
This aerospace disagreement echos with a familiar ring to my software engineering ear. In the one corner we have the folks who want to build the new system with bits and pieces of the old, but who don‘t want to be restrained by decisions made ages ago. In the other corner we have the folks who want to hold on to more of the old design, to bring forward the working bits of the old into the new, more or less unchanged. In short, the second group wants to maintain binary compatibility while the first doesn‘t.
So, the obvious question is: Who‘s right? NASA or the Achieving the Vision authors? I haven’t a clue. This is rocket science after all, a technical topic of daunting scope and complexity. Certainly the Achieving the Vision argument seems plausible to me. But so does the NASA response. Here perhaps is another lesson we can take away from this snapshot of someone else‘s technical dispute: I‘ve been interested in space flight my whole life and know more about it than the average guy on the street. I also studied mechanical engineering, again a leg up in understanding this kind of issue. But I have to admit that I‘m glad I don‘t have to make this call: The quick and easy, seat of the pants reaction to complex technical questions like this are only correct about half the time. The trouble is that no one knows which half.
Aside from the parallels to software engineering, Achieving the Vision is a fascinating look at what it takes to put people in space. It’s the rockets that get all of the attention, but a real space program needs boring launch pads for the rockets to sit on, ground vehicles to move the rockets to the launch pad, workshops to assemble the rockets, test fixtures to … well you get the picture. Achieving the Vision manages to lay this all out for the reader without becoming too mind numbing. For the type of document that it is (a technical position paper) Achieving the Vision is actually very well written and interesting.
Achieving the Vision for Space Exploration on Time and Within Budget. was written by Stephen L Metschan, Cyril A Longton, Ross B Tierney, Antnio H F Maia, and Philip J Metschan and is put out by the American Institute of Aeronautics and Astronautics.