[HS]

Just a bit of a brainwave here, thermal shielding, especially ablative shielding, seems like a big waste of potential energy. Has anyone thought about ways to recapture the energy spent on lift off?

Maybe through a method where a bunch of atmosphere is compressed and then used as a landing jet. Kind of the same principle as a turbine which redirects the fluid in a complete U turn thus doubling the usable velocity. Breaking during compression & decompression.  Alternately/additionally, you could use some kind of mechanical regeneration, like rotors to pressurize a second stage, or to directly generate electricity.

[Korrelan]

https://www.nasa.gov/centers/kennedy/news/rotocapsule.html

[infurl]

If you do a Google search for "regenerative aerobraking" you'll find some references about it.

It looks like the concept has been explored for re-entry on Mars at least.

https://ntrs.nasa.gov/citations/20050209956

I also found this post.

https://space.stackexchange.com/questions/19400/is-there-a-way-to-recover-any-of-the-energy-of-reentry-of-a-mars-lander

[HS]

Thanks, I didn't figure out the correct terminology. People have really developed some next level ideas, wow. Though I didn't find any simple mechanical or thermal-conduction solutions. It's mainly ionization to electricity, and approaches which depend on specific gasses being present in the atmosphere. There may still be room for invention with something that works with "atmospheres" across the board.

[infurl]

Yes it's a really interesting idea and not one that I ever thought of before, though I've been reading about regenerative braking techniques for electric cars for years. Maybe there is a way to harness friction to turn it into electricity instead of heat. Best of all would be a way to turn it into antimatter!

I think ultimately the best way to conserve and reuse the energy would be a space elevator. I haven't heard anything about space elevators for a couple of years but there were quite a few articles about research on them earlier in the decade.

[frankinstien]

https://www.nasa.gov/centers/kennedy/news/rotocapsule.html

Actually, that's an old model rocket nose cone recovery technique.