|
|
|
Elevator to take us into space
SANTA Fe in New Mexico is a Spanish-cum-Indian origin tourist town. We had to go there to attend the wedding of Ye Ling, a Taiwanese friend of our daughter Aliya. It was a marriage with a difference. There was a rehearsal a day before, conducted by an Indian origin spiritualist in a typical Red Indian dress. It was surprising that the groom and his family agreed to this, instead of going to church and saying “I do” before a priest.
But, there was the white Cross of the Martyrs, visible atop Fort Marcy Park, that chronicles a 400-year history of Santa Fe (City of Holy Faith), with the Spanish building tells how in 1610, Spanish colonized the surrounding areas, and onto the progress present-day New Mexico State has made.
During the first week in September, the city sponsors the oldest community gathering of its kind in the country, the “Fiesta de Santa Fe.” This Fiesta was inaugurated in 1692 to celebrate the peaceful return of the Spanish. On the final night of Fiesta Week, Mass is celebrated at St Francis Cathedral followed by a candlelight procession up to the Cross. The Cross was built to honor 21 fallen Franciscan friars in the 1680 Pueblo Indian Revolt. The Indians revolted because of dire straits and poverty brought on by drought, slavery and mistreatment by the Spanish colonialists; with the unfortunate consequence of the 21 friars being killed. Even today, many older Santafesinos of Hispanic ancestry consider walking up the trail as making personal pilgrimages.
It was there that we learnt of the two day meeting of scientists and engineers. We made a point to attend it, because the main topic of the conference was the creation of a space elevator that would make possible of going thousands of kilometres into space of satellites, spacecraft and even people along a vertical track.
Such an idea is not new, but was first mooted in 1979, by Arthur C Clarke, a science fiction writer, in his novel Fountains of Paradise. The idea, after the Santa Fe conference does not looks a science fiction, but a possibility that may come true.
Scientists considered various theories and possibilities and finally accepted that recent advances in materials science - particularly in the development of carbon nanotubes, mean that such a system is not far from the realm of reality.
Science fiction author, Mr Clarke, who once said a space elevator would only be built “about 50 years after everyone stops laughing”, now lives in Sri Lanka, also addressed the scientists at the Santa Fe conference by satellite link and felt confident that his dream that he dreamt in 1979 in his novel may not be far from becoming a reality: it is now upto them to make his dream come true.
The core of the space elevator concept would be a cable reaching up as far as 100,000km from the surface of the Earth. One end of the cable would be attached to a base station on earth, most likely in the middle of the Pacific ocean. The other end would be attached to an orbiting object in space acting as a counterweight, the momentum of which would keep the cable taut and allow vehicles to climb up and down it. At about a third of the way along the cable, 36,000km from Earth, objects take a year to complete a full orbit. If the cable’s centre of gravity remained at this height, the cable would remain vertical, as satellites placed at this height are geostationary, effectively hovering over the same spot on the ground.
To construct a space elevator, such a geostationary satellite would be placed into orbit carrying the coiled-up cable. One weighted end of the cable would then be dropped back towards Earth, while the other would be unreeled off into space. Mechanical lifters could then climb up the cable from the ground, ferrying up satellites, space probes and eventually tourists.
The biggest technical obstacle, according to scientists, is finding a material strong but light enough to make the cable; this is where the carbon nanotubes come in. These are microscopically thin tubes of carbon that are as strong as diamonds but flexible enough to turn into fibre. In theory, a nanotube ribbon about one metre wide and as thin as paper could support a space elevator.
No scientist has yet succeeded in making such a fibre, but Dr Rodney Andrews, a carbon nanotube expert from the University of Kentucky told the conference: “Until some of the basic science concerning how to connect nanotubes together and transfer load between them in a composite is understood it will remain elusive, but a lot of progress is being made.”
Dr Brad Edwards, a space scientist who has been developing the space elevator concept for several years, said there was still a lot of scepticism to overcome. “Initially, people look at me like they’re trying to work out whether or not I’m pulling their leg,” he said.
Dr Edwards says the original satellite used to send up the cable should provide enough tension in the cable for the first vehicles to climb into space, each of which would then be added in turn to the counterweight. These lifters would clamp caterpillar tracks to either side of the cable and would be powered by converting laser light beamed up from the ground into electricity.
“None of it is really extravagant,” said Dr Edwards, who estimates it would take about $7bn to turn the concept into reality. He hopes to have a final elevator design completed by next year. He told the conference that, “the floating base platform would be placed hundreds of miles from aircraft routes and shipping lanes and would be in a region of the sea where storms, lightning and high waves are rare.”
The biggest hazard could be space junk, but Dr Edwards said the floating platform would be moved around to steer the cable out of the way. He says it would slash the price of access to space 400-fold, and could allow cheaper, faster travel to other planets.
The American space agency NASA is also showing an interest in the space elevator concept. It has allocated several million dollars for the project under its advanced concepts programme. Once it becomes a reality, a space elevator would make rockets outdated because it would be cheaper to send sattelites to space.
The writer
|
|
|
|
