First up is Andreas Hein from WARR. Andreas is a long-time contributor in the Space Elevator field. His talk today uses the Brad Edwards model of constructing a Space Elevator and where he believes it must be changed / updated. The upshot of his presentation is that, in his opinion, CNTs may not be strong enough to feasibly build a space elevator and that we should investigate an alternative material – colossal carbon tubes. Andreas also believes an alternative method of deployment, reeling, will be needed along with a round cable in the atmosphere, rather than a ribbon.
Next up is Nelson Semino, the designer of the Space Shaft; an inflatable, atmospherically bouyant structure that allows one to haul up large amounts of cargo to low-space. He proposes a 100km tall structure built out of Hypercubes – boxed-shape bladders that are filled with Helium.
The next talk was by ISEC Board Member, Peter Swan. His talk is “Space environment for space elevators: new insights on space elevator and debris collision probabilities.” Peter headed up the ISEC “Red Team” that has produced a definitive study of the problem of space debris as it relates to a space elevator. Right now, this paper is in peer review. The details (and calculations behind them) are in this report and I recommend that you read it when it comes up, but the upshot is that only at LEO do we have an issue and then, only from the untrackable pieces. It is estimated that the Space Elevator at LEO (200-2000km above earth) will be hit on average every 10 days by a piece of this untrackable debris. A self-repair mechanism must be built into the Space Elevator system, but if that is done, and the design is correct, there should not be a concern that a piece of space debris will ‘take out’ the Space Elevator.