Space rope trick

ASTRONAUTS on February 26 were hoping to perform the ultimate Indian rope trick - by dangling a ball-shaped satellite from a space shuttle as it swept above the earth. But the experiment failed; the cable linking the space shuttle to the satellite broke.

The experiment, which was conducted by astronauts abroad space shuttle Columbia, would have had radical implications for the future of space exploration if it had succeeded. The abortive experiment was to see that whether a satellite can tap into the power of the cosmos, and whether one can harvest electricity from ionised gases.

The tethered satellite, constructed by Italian space engineers, was hoisted out of Columbia's cargo bay by the craft's robot arm which was operated by Swiss astronaut Claude Nicollier. It was reeled out into space on a 19.3 kin-long cable.

As the line swept through Earth's magnetic field, scientists measured the electricity generated along its length. Some researchers believe that such devices could act as alternatives to solar panels for spacecraft.

Researchers also want to find out if cables could be used to transfer energy between a shuttle and the proposed Alpha space station, providing the power io keep the latter in high orbit. Studies were also supposed to have been carried out on the February 26 experiment, to find out if two spaceships linked by a tether and spinning around a common centre of gravity, could generate centrifugal forces to create artificial gravity for astronauts.

I Researchers say it may be possible to use electricity generated on the tether holding the satellite as a new power source for spacecrafts. The technique could also be used to create artificial gravity for astronauts.

The ball-shaped aluminium satellite, five feet in diametre, away into the ionosphere from Columbia. As the tether sliced through the Earth's magnetic field at 27,423 kmph, it generated an electrical potential of 5,000 volts.

However, using wires or ropes to link spacecrafts is fraught with danger in airless, zero-gravity conditions. Astronauts had to abandon their first attempt to fly the tethered satellite two years ago, when the cable jammed.

The abortive February 26 attempt was the second one. Paul Gough of Sussex University (one of the scientists who helped develop the tether) told the press that his team had planned to sue the copper-cored tether to measure how plasma - ionised gases - interacts with electric currents in space, a process that produces effects such as the aurora borealis or the northern lights.

Plasma is the universe's dominant form of matter. It constitutes 99.9 per cent of what the cosmos is made of, and yet we know relatively little about it. This experiment should have helped put that right.