The answer on why we travel in space missed what I think is the most important point. Every now and then, at random intervals, giant asteroids slam into the Earth, causing mass extinctions and economic upheaval. It’s inevitable that another one will eventually come along. If we have enough space capability to detect it and divert it, our species may survive.
Along the same lines, it can be argued that if we can really establish Self-supporting colonies off the Earth we won’t have all our eggs in one basket.
I actually think we are more likely to destroy ourselves than last long enough for a “Dinosaur killer” to hit the earth.
The Economics of establishing viable colonies is still prohibitive beyond a reasonable level however. But we need to get some L5 stations in place, build the Skyhook or Space Elevators and start getting tonnage up into space.
Jim
link to column?
Of course, situations change. The reasons for going to space now are:[ul]
[li]to provide photo-ops for politicians, and[/li][li]to suck away all of NASA’s funding from dangerous, “un-Christian” ideas like global warming or the Big Bang.[/li][/ul]
There’s a silly meme in SF that the Lagrange points would be good places for space habitats. All that a Lagrange point means is that an object there stays in the same position relative to the Earth and the Moon (or relative to the Earth and the Sun, or whatever). But it’s not like a habitat in orbit anywhere else is just going to come crashing down. Any orbit reasonably above the Earth’s atmosphere will stay up forever, and it’s easier to get to lower orbits. In fact, there’s actually a disadvantage, for most things you’d want to put up, to putting them at L4 or L5: Those two points are stable, meaning that junk tends to accumulate there. Which means dust coating your solar panels, micrometeoroids pummeling your hull, and other unpleasant effects.
And unfortunately, Mr. Kennedy’s description of the current vision of the folks behind NASA seems terribly apt.
Which has nothing to do with actually travelling in space. In fact every dollar diverted from real science into going to Mars or wherever increases our danger from this source.
All due respect to Chronos’ physics chops, but I don’t think micrometeories smashing into your solar panels is going to be a bigger issue at a Lagrange point than it is elsewhere. Any particles trapped in there with you are probably moving relatively slowly with resperct to you, so they’d more be sloshing against you. If they move too fast they’ll break out of that precarious state that keeps them in orbit. You could still get hit by paqrticles not sharing the L:agrange point orbit, but that can happen anywhere.
Thwe biggest problem with the L4 and L5 points is that they’re a quarter of a freakin’ million miles from both the Earth and the Moon, out in the middle of nowhere, so that everything has to be ferried there from somewhere else. You thought building on the moon was bad compared to building in Antarctica? well, building at L5 is worse. No gravity. No rock. No shieldfing from radiation flares. You have to travel just as long and as far from either the Earth or the Moon to get there. Then you can slap your forehead and say “I coulda been on Earth by now!” And then you can’t even get reaction mass to get back, unless you cannibalize your stuff. Or get a lot of micrometeorites.
So be sure to back more than what you think you’ll need.
Ok, please withdraw the L5 request and substitute large space stations and then moon bases. The big thing is a project to launch stuff into space in a safer and cheaper way then rockets. The Space Elevator seems like a good way if we can ever get over the technical issues. The Magnetic Catapult of Heinlein’s description is not totally out of the question, but I recall reading the Space Elevator would be the most efficient.
We cannot conquer space with rockets alone. They have no chance of economically moving enough mass.
**To the anti-manned space flight crowd. **
Could you please cite where the Micro-Processor wasn’t perfected by Texas Instruments for the Manned Space Program. This is how I have even heard a TI Rep put it. I think it is poor history to discount the Mercury and Apollo missions affect on developing new technologies.
The Bush proposed and planned Mars Landing seems wasteful even to me. I would rather we channeled more money into Space Stations, planetary Probes and Hubble’s replacements. The Mars Vehicles should probably be built in space, rather than launched from Earth. Build some large useful stations first.
Jim
Perhaps the meme has been reinforced by First Season episodes of Star Trek. There were fully 3 episodes that suggested that power is needed to maintain an orbit.
In “Naked Time” Psi 2000 was breaking up and orbital compensation was more-or-less continually needed. This is sort of a special case; the novelization stated that the breaking-up planet was actually losing central mass (mass closer than any particular close orbit) and that orbital paths which at first were relatively debris-cleared could become problematic without warning. Maybe the whole situation was rather silly. Did they need to be at all close to make their observations? And the whole idea of a planet dying that way seems unlikely to the point of being shlocky.
I thought for years that “Courtmartial” was explicitly silly in this regard. However, just before writing this post I realized something. All that would be necessary for it to make sense is for whatsisname to engineer an orbit (suborbit?) that intersected the atmosphere or surface, and then sabotage the engines. But such was never stated.
In “Mudd’s Women” there was no sabotage, though. Just some miners withholding DiLi crystals needed for replacement. Surely the Enterprise would have assumed a non-Skylab-ish orbit. All together, the three episodes give every indication of a BAD SCIENCE factor at work.
TBJ
Ummm… One sees what you mean, but the last I heard, avoiding a gravity well or two was a good thing for your energy budget.