Science and Society

I can understand NASA's trepidation about this, given Russia's less than stellar performance in space biz. To be fair, though, they have pulled our chestnuts out of the fire more than once. Still, the current problems with Soyuz can escalate. Unfortunately, parachutes won't do the job.

I agree Andy. Parachutes aren't good enough. When you have wings and the ability to control where you go to a safe landing strip, you remove the problems with Soyuz and Apollo capsules. I still say upgrade the shuttles for planet to orbit missions, and use the Apollo-esque craft for interplanetary travel or something like it.

Capsules are NOT the way to go for new space systems. The Russians are experimenting with other re-entry methods and we are going backwards!

Personnel safety is very important and everyone understands this but not everyone understands the risk inherent in spaceflight. It is dangerous now and will be for some time to come. We try to mitigate the risk we know about and generally we succeed. There are still going to be accidents and people are going to be killed. However, there is still a risk when driving a car, flying as an airline passenger and just crossing the street. People who fly these machines accept the residual risk.

By removing an Explosive Bolt and returning it to Earth the Russians are trying to understand and mitigate the risk associated with descent.

The US has much more experience with re-usable winged re-entry vehicles than it does with capsules.

I think the driver for the Orion/Constellation was bureaucratic trepidation about building another re-usable vehicle, coupled with a need to be seen to be doing "something". That "something" had to look and feel different from the current Shuttle system. Politically, this is a very savvy move because the cost of this new "old" system cannot be adequately estimated at this stage and therefore cannot be compared with the cost of the Shuttle; either to procure or to operate for nearly thirty years.

Sure, the Shuttle was expensive and is still expensive to operate but it is a first generation vehicle and should have been replaced 15 years ago.

Quite simply, the Shuttle or a derivative winged vehicle using modern materials and systems is necessary for transporting people to and from Low Earth Orbit. The next version should be people centered with very small cargo accommodations. The cargo transported should be limited to low volume, high value items such as replacement parts and so on. If the size is set to transport say 10 people and a crew of 2 then the overall vehicle is going to be much smaller than the current Shuttle.

We already know how to transport large payloads into space and to retrive stuff from orbit. Bulk cargo can go in the European ATV or Progress or on almost any launch vehicle we have. In fact spacecraft can be assembled from components flown to the ISS or similar platforms and assembled in space. It is then unnecessary to have the spacecraft designed to survive Launch Shock etc. The crude analogy is this: You don't build a ship in the middle of the prairie and drag it to the ocean, you build it at the edge of the ocean and let gravity or the inflow of water to a dry dock do the work. Spacecraft should be built the same way - in Low Earth Orbit.

Andy Clark, an extremely lucid statement of the situation. Although these techniques have been known for years, no one seems to be able to grasp the concept. I think what went wrong was that the politicians got hold of it and bent it out of shape and forced NASA into a position where they bend the knee to the pols or face loss of funding. Not a good situation. Wouldn't it be nice if people who know were allowed to do their jobs?

Andy, thanks for the comment. At SFO we have been pursuing these ideas for about 10 years now. We have published - not widely but locally here in Florida.

We have designed a large Heavy Lift Vehicle capable of placing 170 Tonnes into a 1700 Km Circular orbit. The HLV task is simple - lift cargo; of all sorts to a platform. We plan to recover the third stage and let Stages 1 and 2 fall back.

We can lift enough in a sufficiently short space of time to build a fairly large space base.

The only problem we have is with the manned vehicle that goes along with the other two segments. It is not easy to close the design and there are definite indications that there is a lower size limit for a serious manned vehicle given reasonable operational constraints. I would add that we are not considering an SSTO vehicle at this point. We are currently investigating this lower limit to see if there is any point in getting as close to it as possible. My gut feeling is that there is really no point in doing this but we have to go and investigate the boundaries of sense!

I suspect that some of the government's problems with X-33, X-37 and X-40 may stem from these same constraints.

One thing is reasonably certain though and that is that a manned spacecraft operating in the Earth environment from surface to LEO should probably have wings and normal flight controls. Such a vehicle would not be capable of operating aerodynamically in the very thin atmosphere of Mars and would not be considered for a Moon landing; although with enough RCS/OMS propellant it could probably land on the moon the right side up!

As far as politics is concerned; I think the real reason that pols cannot get to grips with space is because they:

A). Do not understand it.

B). Have not figured out how to make money from it!

Until then we just have to hope for a breakthrough!