I need to become more familiar with the proposed Orbital Space Plane, which is the supposed replacement for the Space Shuttle. So far, the only things I've read so far are this article. It seems to be very well reasoned argument of this vehicles deficiencies by the author, Don Peterson.
The Space Shuttle has a lot of problems, but it also has a lot of capabilities, (decent payload upmass capability, reusability, Extravehicular Activity and Robotics capabilities) which this OSP will not have. Peterson details these deficiencies well. It seems to me this thing is a pumped up X-38, which was the proposed Crew Rescue Vehicle for ISS. (The X-38 was cancelled, limiting the crew onboard the ISS to three, because the Russian Soyuz can only handle that many people.)
My solace in this is that inevitably, the design will change. But I'm not sure it will change for the better.
My impression of the U.S. Space program is that we went from the capability to launch payloads into orbit, to launching a few of people into orbit, to being able to send and return three people to the moon. Then we dropped back to launching a few people and cargo into orbit as well as returning the cargo to being able to construct a large habitable structure in low Earth orbit. We lost the capability to go to the moon. We only temporarily had that capability.
If we go to this OSP, and do not replace the other capabilities of the Shuttle, will have again lost capabilities. If we are going to go to the Moon and Mars we will need to find a way to continue to build large structures in orbit, and to launch and return large amounts of cargo to Earth.
If we don't keep this capability, we will have to relearn it before we send people to the planets, because the spacecraft needed to get there will need to be large enough to accomodate people comfortably for months. I can't imaging traveling somewhere cooped up in an SUV for 6 months. Something about the size of a submarine is the most comparable thing I can envision.
Why do we need to build large structures in orbit? Because the most fuel spent during a spaceflight is to get the payload into Earth orbit. That's why the Saturn V rockets had such a small upper stage (compared to the first and second stage). If instead of launching the entire vehicle into orbit, you bring up the pieces of the vehicle into orbit, and assemble them there, you can get a much larger vehicle ready to go to the Moon or Mars, or beyond.
I hope that we keep our capability.
Posted by Bob at September 24, 2003 08:42 AM