I have been watching From the Earth to the Moon, and just saw Part 4 which dramatised the Apollo 8 mission.
During Apollo 8 the crew placed themselves in orbit around the moon, for one day, and then returned to earth, using a single engine (on the SPS). A big deal was made in this episode about the possibility, but unlikelihood, of something going wrong with the engine, stranding the crew in lunar orbit.
I understand there was no planned contingency or backup system, but with all the people at NASA, someone would have been thinking what might be done in that case? If it didn't fire they surely wouldn't just sit there waiting for their oxygen to run out?
For example, did crew have suits that they could EVA with? (In the episode it was said that the fuel is self igniting and one "only" needs to open the valves.)
What would the procedures be, had the crew of Apollo 8 found themselves in lunar orbit with a non-responsive engine?