There’s been a debate raging within the space technical community and inside NASA over whether or not the Orbital Space Plane should have wings. Obviously, it was named before anyone realized that there would be a debate and the assumption was that, of course, it would.
Jeff Foust has a good overview of that debate, but I want to make a different point, because I strongly disagree with Bob Walker’s comments here, and if they’re true they’re profoundly depressing.
While OSP is portrayed as an interim vehicle, a stopgap between the shuttle and a future RLV, some caution that whatever approach NASA selects it may be stuck with for decades. ?Whatever we design and spend money on is going to be the vehicle for the next 20 years,? said Walker. ?You can kid yourself that there are going to be follow-on vehicles and all that, but we kidded ourselves that way throughout the shuttle program. So you can depend upon the fact that whatever we do here is going to be around for a long time. It seems to me that you want something that at least will be adaptable.?
Two problems. First, I don’t accept that there will be, or at least that there should be, “the vehicle for the next 20 years.” The notion that NASA should have a vehicle is the source of much of our inability to make major space accomplishments.
We have to get out of this monoculture. We need multiple vehicles. And of course, because NASA has no grand ambitions, there’s no way to support their development.
But even if he’s right, and that NASA will have a new vehicle that will be “the” vehicle, it’s not at all clear that simply putting wings on the thing gives you much leverage into the future. It might be necessary (though I’m not sure that’s even the case) but it’s certainly not sufficient. Some fantasize that they can build this vehicle as a payload for a Delta IV or Atlas V, and then later use it as an upper stage for a fully-reusable system.
The problem with that is it implies that that system will be a three-stage system, because the delta-V capability of the OSP is not meant to help get it into orbit–the expendable launcher is supposed to do that–it’s only enough to meet the requirements for maneuvering on orbit, and deorbiting.
If you were designing a fully-reusable launcher right now, I suspect that it would optimize out to two stages. This probably balances the margins needed for operability (provided by staging) against the operational complexity of too many stages. But an OSP designed as a payload for an orbit-capable launch system won’t be optimized for that future vehicle–it will simply be a payload for it as well–not part of the launch system per se. Thus, the notion of using it as the upper stage of a new launch system is a non-starter. That means that the new system must have enough capability to deliver an OSP sized payload to orbit, and, by the logic above, be a two-stage system itself (meaning that the OSP will be the third stage).
If the goal is really to have a space transport, then they should simply build one, instead of building evolutionary dead ends that they hope can be adapted later on.
Of course, this is all beside the point, because what we should really be doing, as a nation, not just NASA, is figuring out how to encourage and nurture a private industry that can not only satisfy NASA’s requirements, but those of the rest of us as well, something that OSP will never be able to do.