Space Rope Trick Experiment Goes Awry

Tjeerd writes "An experiment that envisaged sending a parcel from space to Earth on a 30-kilometre tether fell short of its goal yesterday when the long fibre rope did not fully unwind, Russian Mission Control said. It was intended to deliver a spherical capsule, called Fotino, attached to the end of the tether back to Earth — a relatively simple and cheap technology that could be used in the future to retrieve bulkier cargoes from space.""

Comments

Re:Space Elevators endanger EVERYONE.

[CRCulver]

In the years since the publication of Kim Stanley Robinson's Mars trilogy, alternative models for space elevators have been proposed that would not have the elevator falling down upon the Earth were it severed. See the Wikipedia article on the subject, as this is a frequently asked question.

Re:Is a 30km rope

[eln]

Sure, but to do that, you'd need a 35,786 km rope. I think we're gonna need a bigger spacecraft to haul that thing up there.

Re:Actually...

[lexarius]

But where did you put your magic bag while you were in there? It's dangerous to bring those inside, you know.

Tether Enabled SSTO

[StCredZero]

HASTOL stands for Hypersonic Airplane Space Tether Orbital Launch. This was studied by NASA. We currently have a hard time with a winged craft that can make it to orbit. Space elevators also require "Unobtanium" with unattainably high tensile strengths. But if we combine the two, we get something which is both technically feasible and capable of dirt-cheap earth to orbit. Basically, have an aircraft capable of very high altitude, and about half orbital velocity rendevous with a rotating tether (Rotovator) that can take a cargo the rest of the way to orbit.

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Re:Tether Enabled SSTO

[StCredZero]

Basically, the Rotovator stores kinetic energy which is transferred to the cargo being lifted. The Rotovator can be gradually accelerated back to its former speed by very high efficiency engines, like ion engines. This is much more economical than chemical rockets because: 1) the very high exhaust velocities reduce the fuel required by a couple of order of magnitude and 2) you can refuel periodically using the Rotorvator itself.

In addition, power can be beamed to the Rotorvator from the earth using lasers or microwaves, which further reduces the weight of the entire system.

Re:After a minute and a half on Google.

[Rei]

Ambient "temperature" is somewhat of an abstract concept when there's effectively no atmosphere. What matters most to how warm you are is how much radiation you're absorbing and how much you're radiating. I.e., insulation and color.

There's no way that they didn't consider the temperature of the tether. You consider the temperature of *everything* that goes into space.

What probably ruined this experiment is what ruined past experiments: oscillations. You can get axial oscillations from all sorts of sources, even things as little as variations in the speed of the motor can build up because of resonance. There's almost nothing to dampen them. We've had tethers outright snap because of this. We've also had tethers snap because of other things, of course. My "favorite" was the tether whose insulation had tiny pockets of trapped gas that expanded in the vaccum of space. The tether had become very high voltage because of moving through Earth's magnetic field, and the leak of gas allowed it to discharge in a plasma arc that cut the tether in half.

Not so simple a process as it at first seems.