Space Elevator Teams Compete for NASA Prizes

Hugh Pickens writes "The University of Saskatchewan's has the first place climb in the Second Annual Space Elevator Games being held this weekend at the Davis County Event Center in Salt Lake City. Teams are competing for $1,000,000 in NASA prize money. Although the idea of a space elevator has been around for decades, the space technologies needed to support it have yet to be created. The non-profit Spaceward Foundation has hosted an annual competition since 2005 to build a super-strong tether, or get a robot to climb a suspended ribbon. In the robot climber competition, teams have to get their device to hurtle up a 100-metre-long ribbon, suspended from a crane, at an average speed of two metres per second. The climber must be powered from the ground: strategies include reflecting sunlight from huge mirrors on the ground to solar panels on the climber; shining lasers from the ground up to similar panels on the robot; or firing microwaves up at the climber. Qualifying rounds have been taking place all week, and although high winds and rain have caused delays, four out of eight teams have made it into the finals. There are no outdoor climbs today because of bad weather but some of the tether competitions will happen indoors later this afternoon."

Comments

Don't we need a tether first?

[flyingfsck]

If one can make a strong enough tether, then the obvious solution would be to leave the big heavy motors on the ground and run the tether around space based pulley, but I guess that is too simple to get funding. KISS just doesn't cut it to secure government money...

Re:Don't we need a tether first?

[pushing-robot]

The concepts for tethers usually involve them being thicker in the middle than at the ends, so as to reduce weight in areas that have less load (and don't need as much strength). A looping cable would make that impossible. What might work is a pair of cables that oscillate vertically, out of phase with each other, with a lifter that "walks" up or down by switching between cables as they change direction.

But whether that is more or less feasible than beaming power to the lifter, or collecting power from a conductive cable, is entirely dependent on the tether material, and the tether is a far more formidable engineering challenge. It's silly to design the lifter until we have a design for - or even a means of constructing - the tether itself.

Re:Why can't they be self powered?

[vertinox]

Why do the elevators have to have "beamed power" to them, when they could be self powered like every other "going into space" craft? Why this unusual criteria? To save weight?

Because if the craft could carry its own power supply it might as well be a rocket. The energy required to get into orbit includes its weight in fuel which means you've got to get more thrust which means more fuel which means more requirement in thrust. There is a break even point (obviously), but if you could just haul the cargo up without the extra weight of fuel then you've saved yourself a bit more energy used for the lift which results in an exponentially smaller amount of total energy required.

I suppose they could use complete solar energy rather than "beamed power", but if someone was truly going to get a cost efficient space elevator it would still days a long time to get to cargo into orbit which might last a few days which means you'll have to go through a few days and nights. Of course you could put battery packs on the space elevator for night travel, but again your adding extra weight.

Re:elevator music for 4 months straight

[khallow]

why all this bullshit with laser beams and microwaves? why not power it from a circut printed on the cable? is there some limitation on weight doing so or have they missed the blindingly obvious in their pursuit of the most "clever" solution.

What bullshit? Putting circuits in your cable robs it of strength. Current designs don't have the margin. As usual, the "blindingly obvious" is so only to the ignorant. As a rule of thumb about things that you aren't an expert in, if there's something obvious that isn't done, then the most likely explanation is that you don't understand the system well enough, not that someone is being too clever.

Re:elevator music for 4 months straight

[MarsDefenseMinister]

That's a good problem to have, because we have good solutions to it. Keeping a long pipeline filled (even 4 months) so that it's constantly delivering a stream of material to orbit is trivial. 4 months to orbit won't reduce the utility of a space elevator very much.