Picking up where we left off…
In 1985, Rockwell considered the possibilities of space-based commercial services such as modules added to the Space Station or free-flying on their own and propellant scavenging from the External Tank and OMS pods. in the decades since, neither of these has come to pass. Commercial modules for the ISS have been proposed, but none flown, and certainly no free-flying man-tended commercial space facilities have been launched. Similarly, the idea of scavenging residual propellant is a good one… *IF* you can do it cost effectively. Every drop of rocket fuel returned to Earth is a waste of money and potential, along with being a potential environmental hazard when it’s inevitably just dumped into the atmosphere after re-entry or touchdown.
