No One Wins NASA Space Elevator Contest 240
volts writes "According to New Scientist no one was able to grab the two $50,000 top prizes in the recent NASA 'Beam Power Challenge'. The biggest limiting factor seemed to be that no team was able to meet the speed requirement, although a group from the University of Saskatchewan in Canada set the height record at 12 meters. Not quite geosynchronous..."
Re:The biggest limiting factor seemed to be... (Score:5, Interesting)
Forget solar panels. (Score:5, Interesting)
Re:The biggest limiting factor seemed to be... (Score:3, Interesting)
NASA and other government agencies regularly offer research grants to develop the technology they want. This is just a way to do the same thing on the cheap. Rather than offering several different parties hundred thousand dollar research grants, you offer a prize to the winner of a contest, and hype up the contest. That way, people get fame as well as the possibility of millions of dollars in government contracts if they win.
Re:Forget solar panels. (Score:3, Interesting)
I can see this working. A stirling engine, with the 'heating' chamber on the outside. Target it with a laser (not allowed this year, but will be next), and you'll have a very efficent climber.
You do need to track the machine with the laser (it might help to shoot straight up), and dissipating the heat would be a problem for a 'real' application (heat doesn't dissipate as easy in a vacum), but that wouldn't be a problem for the heights we are talking about here.
I bet we could build one for less than $50 grand...
"Spin-offs" are mostly myth (Score:2, Interesting)
That's what I thought. I was wrong. [netalive.org]
The argument is reduced to spending for the sake of NASA jobs. Communism.
Re:The biggest limiting factor seemed to be... (Score:4, Interesting)
Re:Top Speed (Score:4, Interesting)
Not straight up, you can't.
Geosynch is 35,786 km above sealeve according to wiki. At 3.6 km/h it would take over a year to get up to geosynch
True, but as gravity decreases, you accelerate faster per unit energy. I can't be arsed to actually do any math, but 1m/s at 1G is going to translate into significantly higher velocity the further out you go. Besides which, if you want to use the elevator primarily for moving materiel rather than personnel, a one-year turnaround might not be too bad; throughput is potentially more important than lag.
Even for personnel, that's on the order of time it took to sail from Europe to America via wind power, and people did that.
The length is a problem for power transmission (Score:3, Interesting)
Re:Forget solar panels. (Score:4, Interesting)
Re:Top Speed (Score:4, Interesting)
They may do better if they were funded. (Score:2, Interesting)
It sounds like a great idea, they should sweeten the pot a little more (and I did RTFA, 100K won't be enough either).
Re:The biggest limiting factor seemed to be... (Score:5, Interesting)
"$50K for a design and prototype isn't a lot, but since student labor is basically free most of the money can go towards building the prototype."
As a research professor with students who could have tried to build this thing, take my word for it that it's not enough money. I refuse to have my students doing someone else's research for free; I want to be able to pay them at least $10/hour + tuition remission. For an undergraduate at my fairly inexpensive institution, that's about $7K per quarter, and I'd need three of these. Add a $20K equipment budget and $5K for my time and we are at $46K.
So the budget is $50K. What's the problem? Just the obvious one that my chance of winning is quite difficult to estimate, but certainly way less than 100%. I'd put my expected return at around $5K. There may be institutions and individuals who can afford to expect to lose $41K for the prestige of doing good research and the prospect of future funding. I'm not one, so I'm out.
It doesn't appear that I am unique in these calculations.
By contrast, I just finished a NASA Phase I SBIR. $68,000 over 6 months, guaranteed. If I wanted to do space elevator research, I'd be way better off submitting an SBIR proposal than entering the contest: small up-front risk, higher expected return, better prospects of future funding.
Contests are run because there are often folks who overvalue them, so they are sometimes a cheap way to get things done at the expense of others.
Re:Funny. (Score:1, Interesting)
Last I checked, the Sears Tower's Skydeck is right around 400 meters (quarter mile) off the ground. And they run one single elevator from bottom to top.
This has nothing to do with Otis or any other traditional elevator companies. You obviously do not understand the concept very well to compare the "space elevator" to a traditional elevator. The design philosophy is completely different. The only reason people call it a space elevator is that it lifts crew/cargo from one point to another following a path that is, for the lack of a better term, in the general direction of straight up.
Otis does not build elevators with fixed tethers. Throughout history, elevators have always been built as a big box hung on steel cables with a counter-weight on the other end. The cables get pulled by a motor, and transfers that motion to the big box.
If anything, the space elevator is envisioned to be more like a monorail: a fixed track and the box climbing along it.
Lunar Space elevator? (Score:3, Interesting)
Current estimates [ideosphere.com] suggest that a space elevator will be deployed in 2045 or so. I lunar elevator could be done much sooner-and would have immediate practical value.
Re:Top Speed (Score:3, Interesting)
Why? Elevators would have to pass each other. You'd have to have multiple running at a single time, transferring energy. You can't transfer over the length of the cable, so they could only transfer when close - which means a *lot* of cars going up and down. Plus, at least early-on, up traffic is much more in demand of the cable's stress than.
I actually disagree with him somewhat on this one (largely because regenerating the energy is so very important, not just from an operational-cost perspective given low beaming efficiency, but from a thermal standpoint as well), the cars will be quite expensive just to waste or scavenge for parts in orbit, cargo/passenger return to Earth via rockets is incredibly difficult, and the extra stress put on the elevator isn't too much if you time things right), but the points made are quite valid ones.
I personally would support partial energy recapture, with ultracapacitors or high density batteries storing the energy for discharge in small widened "passing zones" that have embedded conductor cables. You time the launches so that the most stressed section (the connection to earth, which needs to be tiny and where any increase in bearing load propagates strongly along the rest of the cable) only ever has one car on it at a time. The less stressed portions of the cable can bear multiple cars much better.
Re:Top Speed (Score:3, Interesting)
The benefit in the case of the space elevator is that the cost in rocketry doesn't lie in fuel - it likes in production and maintenance. There's a common rule in rocketry that if your fuel costs are a major part of your operational costs, you're probably doing something right.
Cheap way to get research (Score:1, Interesting)
I'm not saying i don't approve, cause there must be alot of research coming out of this contest, but don't sell your soles too cheap.