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-US 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.