Would it be possible to redirect an asteroid into earth orbit; drop some of the highly elastic strings off of that; get delta V for free from the existing potential energies in the solar system.
One problem is what you do with that thing once you’ve used enough potential energy that it’s orbit is touching atmosphere and decaying rapidly. You’d need to blow it up with good timing so you don’t leave fragments in orbit but you also don’t leave large enough chunks to not burn in atmosphere and cause tsunamis when it hits the ocean.
Ideally your tether is going to constantly adjust its orbit so it says far away from the atmosphere, but for fun I did a calculation of what would happen if a 10K tonne tether (suitable for boosting 100 tonne payloads) fell to the Earth. Apparently it just breaks up in the atmosphere and produces very little damage. More discussion here:
Would it be possible to redirect an asteroid into earth orbit; drop some of the highly elastic strings off of that; get delta V for free from the existing potential energies in the solar system.
One problem is what you do with that thing once you’ve used enough potential energy that it’s orbit is touching atmosphere and decaying rapidly. You’d need to blow it up with good timing so you don’t leave fragments in orbit but you also don’t leave large enough chunks to not burn in atmosphere and cause tsunamis when it hits the ocean.
You can absolutely harvest potential energy from the solar system to spin up tethers. ToughSF has some good posts on this:
https://toughsf.blogspot.com/2018/06/inter-orbital-kinetic-energy-exchanges.html https://toughsf.blogspot.com/2020/07/tethers-all-way.html
Ideally your tether is going to constantly adjust its orbit so it says far away from the atmosphere, but for fun I did a calculation of what would happen if a 10K tonne tether (suitable for boosting 100 tonne payloads) fell to the Earth. Apparently it just breaks up in the atmosphere and produces very little damage. More discussion here:
https://www.reddit.com/r/slatestarcodex/comments/1eqe48g/comment/liaouaa/?utm_source=share&utm_medium=web3x&utm_name=web3xcss&utm_term=1&utm_content=share_button
I was proposing something different.