Fuel sent up to space, to be retrieved by returning spacecraft so that any returning spacecraft can slow itself down to a non-dangerous pace.
Hydrogen parcels come to mind since most of the way they will travel by floating upwards.-- pashute, Dec 10 2016 'This is the Captain, no need to worry. We are just passing through the Mentos belt. Some of which, we will pick up on the way'-- wjt, Dec 10 2016 end of era for failing nasa reentry shuttles.-- pashute, Dec 21 2016 random, halfbakery