Posted on 02/15/2006 10:24:11 AM PST by Neville72
In January, LiftPort team members deployed a mile-long tether with the help of three large balloons in the Arizona desert (N Aung/LiftPort Group)Related Articles A slim cable for a space elevator has been built stretching a mile into the sky, enabling robots to scrabble some way up and down the line.
LiftPort Group, a private US company on a quest to build a space elevator by April 2018, stretched the strong carbon ribbon 1 mile (1.6 km) into the sky from the Arizona desert outside Phoenix in January tests, it announced on Monday.
The company's lofty objective will sound familiar to followers of NASA's Centennial Challenges programme. The desired outcome is a 62,000-mile (99,779 km) tether that robotic lifters – powered by laser beams from Earth – can climb, ferrying cargo, satellites and eventually people into space.
The recent test followed a September 2005 demonstration in which LiftPort's robots climbed 300 metres of ribbon tethered to the Earth and pulled taut by a large balloon. This time around, the company tested an improved cable pulled aloft by three balloons.
Rock solid To make the cable, researchers sandwiched three carbon-fibre composite strings between four sheets of fibreglass tape, creating a mile-long cable about 5 centimetres wide and no thicker than about six sheets of paper.
"For this one, the real critical test was making a string strong enough," says Michael Laine, president of LiftPort. "We made a cable that was stationed by the balloons at a mile high for 6 hours…it was rock solid."
A platform linking the balloons and the tether was successfully launched and held in place during the test. LiftPort calls the platform HALE, High Altitude Long Endurance, and plans to market it for aerial observation and communication purposes.
But the test was not completely without problems.
The company's battery-operated robotic lifters were designed to climb up and down the entire length of the ribbon but only made it about 460 m above ground. Laine told New Scientist that the robots had worked properly during preparatory tests and his team is still analysing the problem.
Carbon nanotubes In March, LiftPort hopes to set up a HALE system in Utah's Mars Desert Research Station and maintain it for three weeks. Then, later in the spring, Laine says he wants to test a 2-mile (3.2-km) tether with robots scaling to at least half way up.
Laine aims to produce a functioning space elevator by 2018 – a date his company chose in 2003 based on a NASA Institute for Advanced Concepts study, which said an elevator could be built in 15 years. "This is a baby step, but it's part of the process," he says of LiftPort's recent test.
The idea is to build the actual elevator's ribbon from ultra-strong carbon nanotube composites and to have solar-powered lifters carry 100 tonnes of cargo into space once a week, 50 times a year.
Beams and climbers Laine sits on the board of the California-based Spaceward Foundation, which partnered with NASA to put on two space-elevator-related competitions that were the first of the agency's Centennial Challenges programme – the Tether Challenge and the Beam Power Challenge.
The first is designed to test the strength of lightweight tethers while the beam challenge tests the climbing ability and weight-bearing capability of robots scaling a cable. Laine’s team is not competing in the NASA challenges so there is no conflict of interest.
In October 2005, none of the competition entrants performed well enough to claim the twin $50,000 purses. But the challenges are scheduled to take place again in August 2006 with $150,000 top prizes. Nineteen teams have signed up for the beam power challenge so far and three will compete in the tether challenge.
Ben Shelef, founder of the Spaceward Foundation, hopes the competitions will drum up interest and drive technological innovation. He told New Scientist he is pleased to hear of LiftPort's successful test. "A journey of a thousand miles starts with a single step," he says.
The elevator requires a counterbalance if it is to be efficient. Friction losses only would have to be replaced, and that is a huge problem if this is to replace rockets.
I have no doubt the Space Elevator will be built. And it will make for some SPECTACULAR footage when it comes crashing down.
In case of fire take the stairs?
Hmmm, there's lots of electricity waiting to be discharged somewhere, and a system that needs electricity to run. Hmmmmmmmm.
Unknown. The first problem is to build any kind of structure to the height of 62,000 miles. After that other problems may be addressed.
Out of what? Unobtainium is the only substance known to be strong enough.
Atmosphere is dragged somewhat by earth's rotation, otherwise we'd be feeling a 1,000 mph blast of wind all the time. In fact, relatively little of its length is in the atmosphere, and the stability of the rest of the structure more than compensates.
Talk about vertigo.
On the other hand, a base jumper's wet dream.
The atmosphere, oddly, rotates faster than the earth.
And now you are eluding that you know the process of the coordination of the alignment of the sat's?
here... For you...
http://scisites.msfc.nasa.gov/realtime/jtrack/3d/JTrack3D.html
The sats are adjusted everytime the earth makes an adjustmen...Keeps the guys at Nasa really busy...
Read the third paragraph.
To think that I'll see it in my lifetime...
Yeah, I believe this stunt was tried once... The Tower of Babel?
I would like to work on the computer control that governs the motion of the counterweight system. That would be awesome.
LOL!
"NIce theory, but given wind currents, the torgue of the spinning earth and terrorists wanting to blow it up... it can never happen..."
And men were never meant to fly either, it's un-natural. :)
Actually it was a "large and moving" Torg...you'll recall that was during the Rectification of the Vuldrini.
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