- Related Stories
-
Robots conquer desert, aim for space
October 10, 2005 -
NASA concocting robots for space flights
October 10, 2005 -
Outer space: The in thing
August 10, 2005
That is what scientists call the space elevator. And long before it's ever a reality--if it is at all--scientists must discover the materials, mechanisms and wireless power source to make it work efficiently.
Considering it's no small feat of optics, electricity and mechanics, NASA and the nonprofit Spaceward Foundation are hosting the first-ever competitions this weekend offering $50,000 to teams with the best design of robot climber and ribbon. The competition, to be held here at NASA's Ames Research Center, is merely a conceptual demonstration of the space elevator.
"It's far out for us, but we're very interested in the technologies involved," said Brant Sponberg, NASA project manager for the "centennial challenges," a series of government-sponsored competitions that support space exploration. Sponberg was overseeing setup and tests of the competition on Friday.
The "Beam Power Challenge," which will kick off Saturday at 5 a.m. PST, will test the design and efficiency of robot climbers, machines that can ascend and descend a 50-meter tether ribbon while carrying a payload.
Seven teams from the United States and Canada will get three chances to climb the ribbon, having to travel at a minimum speed of 1 meter per second. For each climb, teams get a score that's a product of their payload mass and average velocity. The team with the highest score will win $50,000.
Many of the climbers are powered by solar cell panels. The Spaceward Foundation will cast a 10-kilowatt light onto the solar panels, if used, to give the bots power up the tether. As the ascent begins, the light will carry as much intensity as three to four suns, but toward the top, its intensity will equal only about one sun.
Steve Jones, undergraduate in the engineering physics department at the University of British Columbia, said his climber needs the equivalent of about two suns to make up the 50 meter tether.
He has been working on the team's climber for the last six months, along with 14 other students. Jones said he was excited about the competition because it isn't obvious how to solve the problem. It's a mixture of optical, electrical and mechanical questions that involve creating a climber, he said, and many teams are coming at the problem differently.
For example, some teams are using solar cell panels, like his, and others, like Starclimber, are relying on a Stirling engine, which can convert heat into mechanical energy with an efficiency of 30 percent to 40 percent, on par with a gas engine and superior to photovoltaic cells.
"This is a great platform for sharing because it's very open. We're seeing each other's designs, and it's accelerating the rate at which we learn," Jones said.
The "Tether Challenge" is designed to help foster the development of strong but lightweight materials that could support the space elevator. The contest requires teams to develop a tether that can improve on a commercially available one by 50 percent in breaking force. Teams will compete in a "pull-off," where each pulls against the other until one breaks, to find the lightest and strongest. Finally, the best-performing tether will compete against the "house" tether, or off-the-shelf material, and if successful, will win the $50,000.
Most people believe that the space elevator will be made of carbon nanotubes, but that technology is still in early development.
"We're trying to use prizes to encourage development of that technology," one project contractor for NASA said.
See more CNET content tagged:
tether, elevator, ribbon, robot, hosting




noted, some spectacular materials technology breakthroughs.
But, so far, every concept seems to have missed the problem of
angular momentum. As the object is lifted, it must also acquire
lateral velocity to remain over the elevator site. (and the site
itself must be on the equator.) As far as I can tell, the lifting
mechanism can't provide that velocity.
Anyone figure it out yet????
pm
Okay, i'm not a scientist, this may be a dumb idea
speed is about 1000 mph. That means that any lifted object
must acquire the additional 4100 mph to keep from wrecking
the elevator. That velocity is a lateral velocity, while the elevator
forces can function only in the vertical direction. Unless the
elevator cable is allowed to depart significantly from a vertical
line, the lateral velocity change requirement is not provided by
the designs illustrated,
In other words, the inventors seem to have forgotten that this
concept exists within a rotating reference frame.
Once you have it start hauling up a payload, then your gonna add a substantial force in the downward (towaed earth) direction and it not gonna take much befor you compleatly mess up its obit and bring the satilite down.
There are two schools of thought, the satilite pulls the mayload up, but what holds the satilite in it's orbit? you'll need fuel for it to main tain it orbit eeuql to if not more than the fuel required to just lift it the triditional way. The payload climbs the ribon up. The problem with that is that you need a ribon able of supporting a paylod 5100 miles, plus it must support 5100 miles of itsself and it must also be able to withstand any forces the weather applies to it and the payload.
So if anyone has any proctical solution for this, I'd love to hear it.
around it so that it move in relation to the earthand does fall
back or shoot off into space.
>> You bet. The satellite orbit is defined by it's velocity/distance
relationship and the local space-time curvature (gravity is
actually an illusion)
Once you have it start hauling up a payload, then your gonna
add a substantial force in the downward (towaed earth) direction
and it not gonna take much befor you compleatly mess up its
obit and bring the satilite down.
>> True, but with a satellite with a mass of millions of kilograms
the mess up is microscopic. But the mess up is also cumulative,
and eventually the elevator configuration will need adjustment.
There are two schools of thought, the satilite pulls the mayload
up, but what holds the satilite in it's orbit? you'll need fuel for it
to main tain it orbit eeuql to if not more than the fuel required
to just lift it the triditional way. The payload climbs the ribon up.
The problem with that is that you need a ribon able of
supporting a paylod 22,400 miles, plus it must support 22,400
miles of itsself and it must also be able to withstand any forces
the weather applies to it and the payload.
>> The satellite may be out at 100,000 miles, so the cable
problem is even more critical
>> The satellite's orbit, as noted above, is defined by its velocity
and distance and the local space-time curvature. (Old theory,
centrifugal force must balance gravity)
>>Once the cable exists, you'll find that the cable itself imposes
far more loads than weather or payload could create.
If the earth and the satellite were actually stationary, the elevator
would be strictly a strength of materials question. The rotating
reference frame of the earth and the rotating satellite adds many
more difficulties.
We can have a pulley hanging form space just above the atmosphere. The pulley hangs from a geo-stationary Space Taxi Station.
A small Space Taxi is released up using a very very large helium balloons. A platform can be made that has large number of huge helium balloons below it. The Space Taxi is stationed on this platform before the whole platform is released.
When the platform reaches to the limit that it rise up in the atmosphere, Space Taxi takes off form the platform using jets propulsion and quickly reaches to the hook of the Space pulley which is just above the atmosphere and hooks itself to it. After this the Space Taxi station just pulls up the Space Taxi. The space station has a counter weight on its opposite side in space.
Note : All this is done with minimum fuel requirements compared to the other technologies, so what say ?
PS. A compressor can be used to bring the balloon Platform back on earth.
wouldn't it be possible for some aparatus to
accend following a RAY from the earth to the satelite????
Heres my idea. You build a very large rail-gun(elctromagnetic) vertically in the ground somewhere on the equator. on the equator because the force required to leave the earth is least there. The rail gun shoots a heavy projectile of aluminum or some sort of metal that gets shot into a "metal parachute". Obviously the metal parachute would have to be strong enough so the round doesn't pierce the parachute but captures the vertical energy. One really nice property about this method is that no petrofuel is used at all. The energy is electricity which can be harnessed from many renewable forms if necessary.
2) It doesn't matter what the energy source is, the problem today is lack of enough energy. Petrofuels are just the cheapest way today to obtain energy (other than nuclear). Renewable sources are just too expensive, inefficient and unscalable today. By the way, most rockets today don't use petrofuels, they use either carbon based solid fuels or oxygen/hydrogen, obtained by using electricity as the energy source for electrolysis.
3) The accelerations on a railgun are so high that almost the only thing you can shot up are raw materials. Everything else would get smashed.
4) The parachute is completely unnecessary. Just calculate the right velocity and the stuff will stop at the right orbit.
...having to listen to three days worth of elevator music as you ascend into orbit!
If we start to beam electrons to the moon, it's only a matter of time before the moon starts to accelerate to Earth. The attraction force between the positive Earth and the negative moon causes the acceleration.
When we pull the moon closer and closer to the Earth, the moon will circle the Earth faster and faster in smaller orbits. Since the attraction force between the two bodies is always equal to the centrifugal force, there will be no impact to worry about.
Maybe we can arrange a controlled touch-down in some way, then, we will have two balls that bite into each other, ocean will form around the connecting ring and most sea bed will become dry land. There will be no month and a day will become about two hours long.
Maybe we can find a perfect orbit that keeps the moon some miles away from Earth and gives us the most benefit.
Maybe after NASA build up space elevator, we can borrow it to shoot some electrons to the moon by using lightning energy.
Once the moon begins accelerating to Earth, acceleration rate will build up aggressively, it is an one way street.
Look into the star sky, I wonder if somewhere someone is shooting electrons at the moon?
It's only a matter of time......till dogs dance on the moon.
- by pirategypsy February 22, 2009 2:35 PM PST
- Ok, the thing I see that may be a problem with the Space Elevator is the drive system that runs it up the ribbon. All the ones I see use wheels to pull it up. But would there be friction to pull it up. In space there is no friction, right?
- Reply to this comment
-
(49 Comments)