Friday, July 18, 2008

Going Up: Slow Progress on 'space Elevator'

Disney World, Epcot, Universal Studios and ... Space Orlando. In the future, Florida could be the site of a simulated "elevator" that allows people to check out life on a space station, virtually.
That's one dream of Bradley Edwards, president of Black Line Ascension and one of the leading proponents of space elevators. The center, which would be a combined entertainment and research facility, could help solve one of the many critical issues plaguing the concept of a simulated space elevator, namely a lack of funding.
At the first space elevator conference in four years, this time in Redmond, Washington, on Microsoft's campus, Edwards announced that he is investigating the feasibility of a combined entertainment and research center, to be called Space Orlando, designed to help fund the building of a space elevator. The cluster of buildings would comprise 2 million square feet (929,030 square meters) and a 10-story-high structure that visitors could enter as if they were walking into a terminal for a real space elevator. They'd buy a ticket, enter the climber vehicle and feel like they're ascending into space, thanks to virtual reality technologies.
They'd step off the climber into space -- or really, a massive room lined with plasma screens displaying what it would look like to be on a space station, looking out into the solar system.
The entertainment facility would also be a working research center. "Wrapped into it are real research labs with glass walls, unfortunately for the researchers," Edwards joked. Visitors would be able to observe the technology the researchers are working on, such as a habitat for people in space.
Edwards estimates the facility would cost US$500 million to $1 billion to build and would attract 8 million visitors a year. Their entrance tickets would help fund the research and development of a space elevator. As Edwards envisions it, a real space elevator, as opposed to a simulated version, would consist of a very long "ribbon" made of carbon nanotubes stretching from a platform on Earth into geosynchronous altitude, around 22,000 miles (35,406 kilometers) above Earth's surface. Lightweight cars would attach to the ribbon and ride up into space. Travel time to the geosynchronous altitude: eight days, moving at 120 miles per hour.
The center could be a relatively easy way to fund research, he said. "Applying for NASA grants is a bit more of a challenge for getting funding," he said. To date, only about $570,000 in funding has been dedicated to the concept of the space elevator in total, he said. "Nobody's getting paid for this," he said.
There are a number of other hurdles, in addition to the funding issue. Technically, scientists are still working out how to piece together carbon nanotube strands at the length required.
One conference speaker pointed out a bigger problem that has yet to be solved. "When you have an object that extends from the surface of Earth to geosynchronous altitude, every satellite currently in orbit, every piece of debris and every satellite in the future will crash into the elevator," said Ivan Bekey, a former NASA scientist currently with Bekey Designs. "Every one, with no exception."
There are about 6,000 satellites in orbit today, he said, many of which are no longer in use. When a satellite hits the space elevator, it would "vaporize it," he said.
So far, none of the potential solutions for avoiding such a collision are viable, he said. The dead satellites essentially can't alter their orbits to avoid the elevator and it would be too costly to require live satellites to move out of the way.
Some proponents say that the elevator could be tethered to a platform in the ocean that could be moved so that the elevator could avoid approaching satellites. That plan opens issues around the oscillations that would travel up and down the elevator each time the platform is moved. Some research into the matter has been done but there's still some uncertainty, particularly around how big the oscillations would be, Edwards said.
The idea of a space elevator grew in science-fiction novels around the 1960s but didn't become a potential reality until the discovery of carbon nanotubes in 1991, Edwards said. A space elevator is of interest to scientists because it could enable a much cheaper method for transporting items to and from space. The ability to move objects easily into space could spawn "the full commercialization of space," including manufacturing, tourism, solar-energy generation and research and development, Edwards said.
NASA has a space elevator on its road map for around the year 2200, Edwards said. But it's possible that a space elevator could come first from a non-U.S. country. Japan currently has a space elevator on its road map for 2030, Edwards said.
Speakers at the conference recognize that the whole concept of the space elevator strikes many people as unbelievable, but they argue that the technology required to build such an elevator is available or at least plausible.

No comments: