NASA requests $2.5 million to study space elevator (scroll down to October 6). NASA recently hosted a conference on nanotubes.
I would personally be delighted if, in these times of massive tax cuts for the rich, massive deficits, and (politically, at least) resultant cuts in all sorts of programs that actually help people, Bush were to propose major new expenditures for manned spaceflight.
Politically, that is. Because we, the good guys, can burn his ass eight ways from Sunday on this one.
On its merits, I think it’s a stupid idea. After thinking about it since the shuttle blowup earlier this year, my thoughts are as follows: that even after, say, a global thermonuclear war, Earth would continue to be a much more hospitable environment than anyplace else in our solar system. IOW, there ain’t nowhere to go up there, so I’d rather not spend the money to go there.
Right now and for the rest of my life, even if the end is still a half-century off, unmanned craft are the perfect explorers. They don’t need food, water, or air; they don’t need to be protected against radiation to nearly the same extent as we do. We can send dozens of space probes for the cost of one manned mission. Heck, I’d bet we could figure out how to send an unmanned craft to Alpha Centauri in a tolerable amount of time and have it radio intelligible data back to us, more cheaply than we can put human beings on Mars - and we’d learn a lot more.
All we learn from manned missions in space is how to survive for brief periods in space. IMHO, it’s an overrated skill that we can relearn when there’s a better reason.
That’s silly. It’s four light years away.
If you only send robots, why go at all? Spend the money on seat bellts, bicycle helmets and carefull, safe things here at home.
:rolleyes:
RTFirefly, humanity has been trying for thousands of years to find an end to poverty, war, disease, homelessness, and a host of other ills and haven’t succeeded yet. Maybe that’s because we’ve been looking for the answers down here, when, in fact, they are up there.
One shuttle load worth of H[sub]3[/sub] from the Moon (yes, I know, the shuttle can’t go that far) would provide enough energy to meet a nation’s electrical demands for a year.
And this statement of yours
Is flat out wrong.
And thanks to NASA’s research into manufacturing in microgravity environments a unique form of glass has been created which
If something like the space elevator comes about (i.e. a cheap way to get to Earth orbit), you can expect to see the majority of manufacturing jobs move to space. Why? Because the microgravity environment enables us to do things that we simply can’t do here on Earth. Perfect ball bearings is an example, they’ll have a longer life, and lower friction resistance than bearings made on Earth. This means cars will get better gas milage (thus saving fuel) and last longer (thus saving materials). Parts can be made with greater precision, since they won’t sag under their own weight due to being in a gravity field, so they’ll last longer (Ford discovered back in the 1980s that transmissions made to closer tolerances needed fewer repairs than ones made to looser tolerances.), and experiments have shown that castings made in microgravity environments are stronger and lighter than castings made here on Earth (not to mention that the material is evenly distributed throughout the mold, instead of being concentrated at the bottom of the mold).
A space elevator means lots of cheap, reliable solar power for the Earth (the nanotube cable will conduct electricity quite well), this means less reliance on fossil fuels, which means less pollution. So what if humans can’t live easily on Mars? There’s enough positives in just being able to get to Earth orbit cheaply to make it worth the effort. Besides, as Robert A. Heinlein put it, “Once you’re in orbit, you’re halfway to anywhere.”
An interview with the heads of the Prometheus Project can be found here. In reading the interview, it doesn’t look like the engines will enable faster travel times, though they will last longer than current ion-engine designs.
Thanks for the link. It’s very interesting. But I didn’t really get the sense that the HiPEP engine wouldn’t allow faster travel times. Basically, with this engine you get a lot more total impulse, because it has a higher specific impulse than chemical rockets and can fire for a much longer period of time.
Now, does that mean the Jupiter Icy Moons orbiter will fly to Jupiter faster? Maybe not. In the case of this specific mission, the extra impulse and long lifetime of the engine is going to be used to allow JIMO to zip around the Jovian system from moon to moon. However, they may fly a direct minimum-fuel orbit to Jupiter like the earlier Voyager missions did, rather than having to use the time-wasting gravitational slingshots a la Cassini.
On other missions, though, you might see faster speed. Missions to earth-crossing asteroids, Mars, etc. could benefit from that engine, I would think. It’s pretty cool that it can be scaled up easily to produce more thrust.
Prometheus has been rolled into the new office of exploration, which is going to have a massive budget. How much goes to Prometheus isn’t clear, but I think we’re headed for very exciting times in space exploration in the next couple of decades.
Well, they really don’t say anything about travel times, so it’s hard to say. Still, I have to think that if they believed it could reduce travel times, they’d have mentioned something about it.
And Sam, I hope you’re right about these being exciting times, but I’m not going to be holding my breath.
That’s a variant of an ion rocket. It’s painfully slow, actually. Impulse over time is just great if you want to keep a long platform lifetime, but otherwise it’s not going to get you anywhere fast. But on the bright side, since you’re using a nuclear-electric source, there is little need to worry about when you set the thing off. It just goes and goes… slowly. No need to worry about Hohmann transfer orbits since whenever you set off you can calculate a minimum energy path which will closely approximate a Hohmann, but with a more distant arrival time.
What I hope and pray they’re going to incorporate into such a machine is the ability for a future probe to dock and recharge itself with the reactor even after the original craft is out of maneuvering fuel. What the far planets really needs is a power plant. That’s where a reactor really benefits, because it provides a large source of energy in a place which is not particularly overabundant in simple energy sources.