Oz Lander" wrote Question answered. Thanks.
I guess that's where the solar sail technology might one day come in
handy.

Not really.

The whole idea behind a solar sail, is to exert a tiny force on a spacecraft
for a very long time, and accelerate it for a long trip between planets.

It would be able to do nothing for slowing down for re-entry.

Really, the ONLY answer is a thrust with tons of force exerted over a very
short time period. Right now, that is chemical burning of something,
and........ that's it!

The other thing left is aero braking, which is what we do now, and have done
for all past programs, and has been done by the Soviets.
--
Jim in NC