January 9, 2004

Going where man has gone before (and got bored and left)

Posted by Arcane Gazebo at January 9, 2004 3:04 PM Since hearing about Bush's impending space exploration announcement, I've been wondering if it really makes sense to use a moon base as a steppingstone to Mars. As it turns out, Gregg Easterbrook has the numbers, and the answer is no.

Add me to the list of people who can't figure out what possible use a moon base could have. (A manned mission to Mars at least has some romance to it. If only we could afford it...) Tags:

What do we need a moonbase for? How about as a place to send this happy couple.


Posted by: Jeremiah Spur | January 9, 2004 3:43 PM

THANK you!

This is EXACTLY what my friends and I were talking about Friday night. What is the point of a station on the moon? We couldn't find a reasonable answer to that question other than "Spend lots of money in a completely useless way...and...yeah, that's all we've got."

So hey, Science Man, here's my question: Will we ever have the technology available to really explore space?

Posted by: Tracy Manford | January 12, 2004 5:41 AM

Re: THANK you!

I would say that solar system exploration is within our reach right now, technologically speaking. The primary obstacles to a manned Mars mission seem to be economic. There is the problem of speed; Easterbrook's estimate is a minimum six-month travel time which sounds about right if not on the short side. This isn't too bad; astronauts have spent longer on space stations after all. But it is a problem for the outer planets; Jupiter's minimum distance from Earth is over 8 times that of Mars, which means at least a four-year one-way trip. So our current technology really only gets us Mars, Venus, and Mercury if we have adequate radiation shielding.

There's no physical constraint on zipping around the solar system faster than this; we just need an upgrade in propulsion technology. One proposal that gets some attention involves harnessing nuclear energy. Of course international agreement prohibits the detonation of nuclear weapons in space, but since the current administration uses nuclear treaties primarily to stock the White House restroom stalls, this isn't really an obstacle. So that might work.

I'd love to see a Cowboy Bebop scenario in which the interplanetary travel time is roughly a week, but it's hard to see how that could be accomplished.

Then there's the issue of interstellar exploration which is where you bump into relativity. There's good news and bad news. The bad news is that it gets harder to accelerate the closer you get to the speed of light. But the good news is that distances get shorter as you speed up. So despite the fact that Alpha Centauri is four light years away I can, in principle, go there in a year, provided my propulsion is good enough. To the observers on Earth it will take a lot longer, of course.

There's the question of how much energy a mission like this would require and whether it's remotely feasible. Also I wonder about whether the human body can survive the necessary acceleration (but I'll need to get out my relativity books to remind myself how that works). I may run some numbers later (i.e. when I'm not in lab) and make a post out of it.

Posted by: Arcane Gazebo | January 12, 2004 2:50 PM

Re: THANK you!

That makes a lot of sense. It's interesting, hardly any of the mainstream television/movie sci-fi (at least the sci-fi I've seen) ever brings up the issue of time passed in space versus time passed on Earth. It's not very encouraging, I guess, to know that, sure, you can explore space, but no one that you know will be the same, or possibly even exist when you get back. Yikes.

Your White House comment made me laugh and laugh and laugh....

Posted by: Tracy Manford | January 13, 2004 5:37 AM

Re: THANK you!

Yeah, I can't think of a single on-screen example of relativistic concerns being respected in sci-fi. It seems like the vast distances involved in space travel are such a problem for storytelling that nearly every writer has to imagine a way around relativity: warp drive, hyperspace, whatever.

The film Aliens somehow manages to come close without actually managing to be correct. At the beginning Ripley arrives on Earth 50ish years after her departure without having aged significantly. They could have used relativity as the explanation, but instead it is because her shuttle drifted for 50 years before being rescued, and she was in suspended animation during this time. On the other hand, if the technology of Aliens were sub-light-speed Newt would be long dead by the time Earth received the colony's distress signal. So I suppose it was not possible for story reasons.

Posted by: Arcane Gazebo | January 13, 2004 2:30 PM
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