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FullOfStarships t1_jcabdpw wrote

NASA needs to build on their own previous research on electromagnetic EDL - "Magnetoshell Aero Capture":

Click through to the PDF for detailed info on their modelling, EG aerocapture of a 60t spaceship at Mars replaced a 20t heatshield with a 1t magnetic system. Also 20km/s aerocapture at Neptune.

"This means that for any given breaking drag forces on the Magnetoshell will be three orders of magnitude larger than the aerodynamic forces on the spacecraft. With the ability to rapidly and precisely modify the drag in varying atmospheric conditions, much larger braking forces can now be contemplated at low risk, enabling very aggressive aerocapture maneuvers."

The thing that makes this suitable is that when you turn the system on it basically kicks in the atmospheric reentry much higher than normal. You then adjust the magnetic field strength to accurately target the deceleration that you have pre-planned.

Some concepts that I've seen literally put the system on a tether behind the spacecraft, and it acts like the parachute behind a drag racer or a plane landing on a short runway. Nice feature of this is that it's a dynamically stable system - it just brakes in a straight line.

Just what this needs.

I'm honestly disappointed that SpaceX aren't testing this. Not because it's their patriotic duty to do everything interesting in spaceflight, but because they're launching 100 F9US this year alone, and every Starlink mission should be testing this during U/S disposal post mission (after all payloads have deployed).

Exactly like they tested reentry of the first stage long after MECO / stage separation / payload in its way to orbit. Zero risk to mission success.

First target should be to slow down FH core stages so they can survive F9-style reentry and recovery.

Also, those simulations were based on "room temperature" copper coils to reduce the technical complexity of the system during testing phase.

There are now very low mass / high performance thin film superconducting tapes which would be perfect for this job, I think. There will be LOX residuals to provide the cryocooling.

I'd love to see a world where every Starship uses this to reduce the performance requirements on the heatshield. Starship docks behind ISS, switches on the MAC, targets the reentry, then un-docks, reboosts itself, and lands safely.

(Before you say "why Starship"? ISS is about 4x the dry mass of Starship. If MAC is in regular use in Starship EDL, then it will work on a combined Starship / ISS system by just running the MAC for 5x longer than normal.

If any other provider is going to be in a position where they have 100t+ spaceships in regular use, ground control teams with years of experience with ISS rendezvous, MAC built into the system [I can dream], etc, etc, then perfect. But I'm not seeing it.)