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Rockets are the workhorse for getting into orbit but they are expensive, consume lots of one time use fuels and are dangerous. Super guns have been proposed but so far not a single launch has been successful. Space elevators have been proposed which dangle a super strong cable all the way from geosynchronous orbit down to earth using a cable. Unfortunately the breaking strengths of even tapered cables are far to short to lift anything from the surface up to the orbiting space station. And installing one of these would be a bit worrisome. There is an obvious solution but it would require some time to get it set up and operational.

Bring a large asteroid into near Earth orbit with its perigee dipping at a safe distance, about 100 km, and the apogee at perhaps the geostationary distance of 36,000 km. A cable would be dropped to an altitude attainable by a jet airplane, about 15 km, and a transfer load on the top of the plane hooked up to a tether as the two are at the same place at the same time and speed. If the mass of the asteroid is much greater than the transfer load and the tether were strong enough the load when hooked up and released from the plane would soon be lifted into outer space and after a while up to the top of the asteroids orbit. If the load were disconnected at the top while being flung forward with its still existing rotational momentum at the outermost limit of rotation it would approach the orbital velocity needed to maintain that orbit. There would need to be some rocket input to make adjustments.

To accomplish this would require the asteroid to be rotating at a precise speed and have an 85 km tether fixed to it. A weight at the tip end of the long tether would needed to counter the drag of the tether hanging through the upper atmosphere. Or perhaps a small jet engine and control surfaces that would help adjust the hooks moving to the speed of the jet plane. As the airplane approached this swinging hook there would be a period of a few seconds where the hook and the plane would be traveling at the same speed and the intended transfer load could be hooked  and lifted away. This of course requires precise timing, and some flight control for the final hookup but with modern telecommunications and fast computers these things might be accomplished routinely.

The payoff of these shenanigans is that a large amount of mass could be lifted from the surface of Earth up to an Earth orbit, and even up a geosynchronous Earth orbit as cheaply as flying an airplane and its cargo to the high altitude transfer point. Of course you must coax an asteroid into just the right place and rotational rate. That might not require too much energy if the time available was long enough to coax the mass around some complex but energy free path from the asteroid belt. Of course people might be concerned about bringing a really big asteroid that close to an Earth collision. But, we don’t need to worry personally, this set up would probably take a couple hundred years to get a spinning asteroid into this type of Earth orbit.

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