I'm not sure you remember I already looked at this subject. It was on April 21 and I really enjoyed this headline: "Penthouse suite: 11,457,600th floor - lots of room - great views."
Now, it's time to revisit the subject, with Ron Cowen as our guide.
The space elevator "is no longer science fiction," says David Smitherman of NASA's Marshall Space Flight Center in Huntsville, Ala.
Physicist Bradley C. Edwards agrees. He left a job at Los Alamos (N.M.) National Laboratory to work full-time on the elevator design for a private company, Eureka Scientific in Berkeley, Calif. Edwards says that the elevator could be a reality in just 15 years. He presented his latest ideas in August at a workshop on the space elevator in Seattle.
Carbon nanotubes are the strongest material known today and are easier to make than before. These scientists -- and others -- want to incorporate these nanotubes into fibers and ribbons to build the space elevator.
Besides this difficult task, there are other technical challenges.
For one, the ribbons would act as lightning rods, the path of least resistance between a thundercloud and Earth. The heat generated by a lightning strike could sever a ribbon. One solution, says Edwards, is to place the ground station in a zone off the coast of Ecuador that receives few lightning strikes. The floating station could move the lower end of the cable out of the path of the rare storms that do occur in that region.
Micrometeors and humanmade space debris punching through a cable pose another hazard. Widening the cable in the region where space debris is most common -- between 500 and 1,700 km above Earth -- should make the elevator more tolerant of these random hits, Edwards says. Nonetheless, minor impacts from asteroid debris and damage from other hazards are inevitable.
"Think of the space elevator structure as a 100,000-km-long highway that will require ongoing maintenance and repair," says Smitherman. It will stretch 2.5 times Earth's circumference.
I don't know if this space elevator will ever be built, but it will take years and billions of dollars. And the round-trip ticket might cost only $20,000.
Source: Ron Cowen, Science News, Week of Oct.5, 2002
6:41:30 PM
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