Posted on 06/25/2004 2:21:35 PM PDT by Junior
WASHINGTON - President Bush (news - web sites) wants to return to the moon and put a man on Mars. But scientist Bradley C. Edwards has an idea that's really out of this world: an elevator that climbs 62,000 miles into space.
Edwards thinks an initial version could be operating in 15 years, a year earlier than Bush's 2020 timetable for a return to the moon. He pegs the cost at $10 billion, a pittance compared with other space endeavors.
"It's not new physics — nothing new has to be discovered, nothing new has to be invented from scratch," he says. "If there are delays in budget or delays in whatever, it could stretch, but 15 years is a realistic estimate for when we could have one up."
Edwards is not just some guy with an idea. He's head of the space elevator project at the Institute for Scientific Research in Fairmont, W.Va. NASA (news - web sites) already has given it more than $500,000 to study the idea, and Congress has earmarked $2.5 million more.
"A lot of people at NASA are excited about the idea," said Robert Casanova, director of the NASA Institute of Advanced Concepts in Atlanta.
Edwards believes a space elevator offers a cheaper, safer form of space travel that eventually could be used to carry explorers to the planets.
Edwards' elevator would climb on a cable made of nanotubes — tiny bundles of carbon atoms many times stronger than steel. The cable would be about three feet wide and thinner than a piece of paper, but capable of supporting a payload up to 13 tons.
The cable would be attached to a platform on the equator, off the Pacific coast of South America where winds are calm, weather is good and commercial airplane flights are few. The platform would be mobile so the cable could be moved to get out of the path of orbiting satellites.
David Brin, a science-fiction writer who formerly taught physics at San Diego State University, believes the concept is solid but doubts such an elevator could be operating by 2019.
"I have no doubt that our great-grandchildren will routinely use space elevators," he said. "But it will take another generation to gather the technologies needed."
Edwards' institute is holding a third annual conference on space elevators in Washington starting Monday. A keynote speaker at the three-day meeting will be John Mankins, NASA's manager of human and robotics technology. Organizers say it will discuss technical challenges and solutions and the economic feasibility of the elevator proposal.
The space elevator is not a new idea. A Russian scientist, Konstantin Tsiolkovsky, envisioned it a century ago. And Arthur C. Clarke's novel "The Foundations of Paradise," published in 1979, talks of a space elevator 24,000 miles high, and permanent colonies on the moon, Mercury and Mars.
The difference now, Edwards said, is "we have a material that we can use to actually build it."
He envisions launching sections of cable into space on rockets. A "climber" — his version of an elevator car — would then be attached to the cable and used to add more lengths of cable until eventually it stretches down to the Earth. A counterweight would be attached to the end in space.
Edwards likens the design to "spinning a ball on a string around your head." The string is the cable and the ball on the end is a counterweight. The Earth's rotation would keep the cable taut.
The elevator would be powered by photo cells that convert light into electricity. A laser attached to the platform could be aimed at the elevator to deliver the light, Edwards said.
Edwards said he probably needs about two more years of development on the carbon nanotubes to obtain the strength needed. After that, he believes work on the project can begin.
"The major obstacle is probably just politics or funding and those two are the same thing," he said. "The technical, I don't think that's really an issue anymore."
With or without paint?
Speaking of cowboy... it would be the world's longest bullwhip
The response I've seen to this requires letting out a counterbalance weight further into space to counteract the effect of changing the weight distribution as the cab goes down. I don't fully understand it, but I know space elevator theorists have at least addressed that question sufficiently for it to get reported somewhere on the internet.
Well, they'll have to kill every islamic nutball first.
Why not offer all them a ride up the cable to meet Allah? Surely they could not refuse!
Smiles. Well if you went fast enough, you better paint it. Sunburn city. :-)
I'll bid 6850, but not 7000. In any case the several day's journey either up or down can shed that velocity comfortably.
It will be about 6000mph, which will have to be braked to the 1000 mph surface speed, as the elavator cab travels a distance of 18,000 miles The numbers might be awesome, but I'm not seeing a problem here.
Actually the numbers (about 0.3 mph/mile) are about one percent of the sideways work that has to be done during a carrier aircraft landing because the flight deck is angled 10° to the centreline of the ship - itself not significant, and there it happens in a few seconds, not the 50 hours travel an Earthstalk cab will have.
elevators work BECAUSE THEY ARE INDOORS, AND DONT STRETCH FOR MILES.
this is f'n stupid.
have a great day :)
I.e. let another cable out from the cab as it goes down the ribbon?
Hmm. How about all those thousands of non-synchronous satellites and assorted space junk whizzing by the thing?
Actually, I'm describing the dynamics of tethers in space, with which I've had some practical experience.
Everyone probably thinks we're nuts right about now. (Me, I think the guys behind this must come from a planet without a moon. :)
Hmmm, sonic stresses COULD be a problem.
They would be a severe pitting problem. The International Space Station would put quite a ding in the Space Elevator.
(In my best Dr. Strangelove voice):
Let's see. Radius = 4K miles(Earth) + 62K miles (elevator) = 66K miles.
Circumference = 2piR = 415K miles/24hrs = 17,000 mph at 62,000 miles.
And that "horizontal" speed must drop to zero by the time the cab reaches the ground. He's talking about an 13 ton elevator -- Where do we get the energy to stop 13 tons moving at 17,000 mph?
Conversely, where do we get the energy to accelerate 13 tons to 17,000 mph?
You can neglect the perturbations on your system. But rest assured they will not neglect you....
Oh, it will dodge :-)
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