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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."
This gives a whole new meaning to "leaking gas on the elevator"
find -name "*base*" -exec chown us {} \; ; ln -s
For a blue-sky vision of a future with a functional space elevator, I'd recommend reading Arthur C Clarke's Foundations of Paradise novel.
"I bless every day that I continue to live, for every day is pure profit."
WILLIAMSBURG DOESN'T NEED A SPACE ELEVATOR! The Space Elevator Will Mean: Less Parking, Weird Ribbon Thing, Constant Loud Whirring Noise, Increased Space Elevator Truck Traffic. Developers have submitted plans to build a massive space elevator in Williamsburg! This monstrosity, completely out of context with existing development in the neighborhood, will be accessible only to the wealthy, forcing thousands of average Williamsburgers from their homes and live-work spaces! Jobs the elevator will generate (operators, repairmen, astronauts) are certain to go to non-residents! Don't sit idly by and let this elevator cast its impossibly long, cold, and very narrow shadow over our homes! CALL 311 AND TELL THEM 'I JUST DON'T NEED THIS SPACE ELEVATOR!'
roll her over and try the other side.
Do you even lift?
These aren't the 'roids you're looking for.
I wonder if you could use a screw. I wonder what the momentum would be on a 22,000 mile screw? What would the torque required be? Or could you use a long two-way cable with a pulley at the end such as those on a ski lift? What about helium or hydrogen? When the air got too thin to provide much lift, the hydrogen could be burned in a rocket or fuel cell or something else. What about a sterling engine? Couldn't you fly the far end out to 44000 miles, and use the thing on an incline as the earth's rotation pulls it around to the tangent?
Cool! Amazing Toys.
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...
Excuse me, but please get off my Pennisetum Clandestinum, eh!
Meesa wanna haul fuelsa insteada payload. Takesa twicea longa!
If you were blocking sigs, you wouldn't have to read this.
Given that the materials required to make them are completely conjectural, you can imagine any conductivity you like. From all the sparkling, I think that fairy wings must be pretty conductive, so let's make space elevators out of them.
If you were blocking sigs, you wouldn't have to read this.
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.
"I am the king of the Romans, and am superior to rules of grammar!"
-Sigismund, Holy Roman Emperor (1368-1437)
I think maglev-accelerated rockets has more potential than the space elevator. Whatever happened to that research at NASA?
I'd like to see a competition to shoot a sensitive cargo (an egg perhaps?) the furthest distance using some kind of maglev catapult without the cargo breaking. Casing of any kind, wings and a parachute are allowed.
Unlike a space elevator which either works or doesn't, this stuff has potential even if never gets anyone into space. Trains obviously, aircraft, weapons or even quick delivery systems could build on this technology.
Nah, that tastes like crap.
Getting into orbit isn't about altitude, it's about velocity. Run the numbers for a massive lifter. You might gain 5-6 miles worth of altitude, and less than Mach 1 velocity. That still leaves you needing a lot of acceleration to make orbit. It's nice for Spaceship 1, which is only suborbital. It's even the chosen approach for Pegasus, which puts some small stuff into orbit. Ultimately, for small craft it is marginally useful for avoiding a few troublesome parts of lifting off from the ground, but such an approach is useless for large launches.
Just a few corrections to the article:
:-)
The youtube link is to the U of S's winning round last year; it's now the third annual space elevator competition. The rest of the article is correct. It's worth noting that the height and speed requirements are double what they were last year.
Hopefully the weather will be better tomorrow and the competitions will continue! All the best to all the teams... and especially the USST, of course.
A moving cable driving by motors would not scale very well. Imagine the momentum of a cable moving in a 22,000 mile long loop. The energy required to get it moving would be tremendous, and the problem of stopping it again would be immense.
Life is like a web application. Sometime you need cookies just to get by.
I'll second your pessimism. There's really only one real scientific challenge, and that's the tether. We're an order of magnitude from the required strength, and meeting the required strength may well be *physically* impossible. Most economically viable designs call for 100-120GPa tethers with the density of graphite. Yet the strongest *inividual* SWNTs measured so far are only 60 GPa, let alone the strength of tube bundles, let alone the strength of a mass-produceable fiber. And what sort of stronger bonding structure do people expect to find than graphene's SP2s?
These little "space elevator" contests and companies that address everything but the tether always amuse me. I always picture something like:
"Good news, everyone! Progress on my 'Teleportation Shoes' has been proceeding wonderfully. We've developed a shoelace that fits into the loops perfectly. The insoles have been rated as "quite comfortable", and while the rubber for the heel has been stalled by supply problems, we're certain we can get these resolved shortly.
Teleportation will be addressed at a later time."
Son, a woman is a lot like a refrigerator. They're six feet tall, 300 pounds... they make ice... umm...
Flat out wrong.
http://www.richard-seaman.com/Aircraft/AirShows/SpaceShipOne2004/
From the article:
The White Knight drops SpaceShipOne when they reached an altitude of about 50,000 feet (15 kilometers), and it takes 30 or 40 minutes for them to reach this altitude. Along the way they levelled out for some time while they checked all of the onboard systems.
PHOTOS
As they spiralled higher above the desert, it became harder to even see where they were; eventually, though, they got high enough for contrails to start forming. Finally, around 7:50AM and 47,000 feet (14,250 meters) the White Knight released SpaceShipOne, which glided for about 10 seconds then lit its rocket engine.
So yes, they use a rocket in the second stage, but describing it as a "mobile launch platform" makes it sound like an aircraft carrier. They used conventional lift to reach almost to the top of the stratosphere before firing off the rocket.
-1 Uncomfortable Truth
There's also the construction and materials movement. If we have spacecraft capable of moving an asteroid into geostationary orbit, and putting the initial construction team and equipment on it, chances are they'll be good enough to make the tether redundant.
I have to admit though, I don't even like the concept of a space elevator. Centralised, large scale, multiple single points of failure, untested tech, extremes of environmental conditions; any one of these phrases sends a shiver of fear down a reliability engineer's spine.
"I've got more toys than Teruhisa Kitahara."
The highest altitude an airplane can sanely go to is say 20km, a hot air balloon can go higher but they have a very limited payload capacity. Spaceship one got detached at 15km for comparison so I'm being quite kind here, in your favor. Now let's look at some actual numbers, something I assume you're incapable of doing on your own due to lack of intelligence despite the trivial difficulty of it.
The most fuel is consumed attempting to overcome the higher gravity at earths surface, which is 9.78 meters per second per second down near the equator and drops in a non-linear fashion with distance,
Apparently you cannot comprehend the massive distances involved. At 20km, see above for why I use this, the acceleration due to gravity is 9.76. At sea level it is 9.82. Non-linear means jack shit when you start at 6371km and only go up a few dozen km. 0.7%, yeah bloody helpful.
and ploughing through the earths atmosphere, which generates drag and heat.
The amount of energy lost to drag is quite small, a quick calculation puts it at below 0.1% (of the thrust of the rocket) between 0km and 20km (velocity and atmospheric density cancel out more or less I think as you go up). Also at 20km, the highest you'll realistically get a plane to go, is still well within the atmosphere.
So you will need to send a rocket up anyway, specifically one that detaches from your lift vehicle. No spaceship can "pick up" your rocket because any such spaceship would no longer be even close to in orbit (to be at such low altitude/velocity). If you want me to explain the absurdity of it more then I will but hopefully I won't need to.
So let's look at the savings of launching at 20km instead of 0km altitude, the starting velocity in both cases will essentially be 0 (even 500km/hr is nothing).
The Soyuz launch vehicle, for example, drops it's first stage at 50km and has a velocity of ~2km/s or so I think. That stage is 30% of the whole things mass/fuel, the remaining mass is still ~120 TONS. Let's ignore the absurdity of trying to list 100+ TONS to 20km by airplane (needed for sizable payload), it's more than a 767 can lift which can't even go close to that high. Now you'd get a savings of maybe 10-15% of total at 20km once you take away those 0.5km/s of velocity it no longer has. The cost and complexity of dragging it that far up, by airplane, would more than counter any savings. Also even 20% savings is small as the cost is still absurd, a space elevator gives you maybe 95%+ savings over current rockets.
Which also causes the explosions that plague rockets.
And trying to ignite at high altitude, separate from a plane and so on will cause it's own problems. Modern rockets are decently safe.
Are you saying that the fuel you save utilizing conventional lift to reach the top of the atmosphere instead of using rockets is irrelevant?
Of course it is, fuel is amazingly cheap compared to all the other costs involved. The space shuttle for example is not absurdly expensive because of fuel but because of how complex it is to deal with (billions a year just to keep the launch facilities in working order). Your ideas are complex, compared to rockets, and so would incur massive costs of this sort.
It's so obvious that everyone in the private sector who is attempting to enter the arena of space flight has chosen this approach, including SpaceShipOne, which is functionally demonstrating the concept.
You picked the perfect example to discredit your own point. They could do it BECAUSE they didn't need to generate high velocities. They were orders of magnitude off from what any traditional rocket needs in terms of velo
Like an electric counterweight.
My ism, it's full of beliefs.