Doug... wrote in message
...
In article ,
says...

snip

2. The Reentry Attitude Control System (in the nose of the Gemini
8,usually only used during reentry) was turned on to regain control of
Gemini 8. Once this system was activated, the flight rules said they
must land as soon as possible.

I just wanted to point out that there was a little softness in that "as
soon as possible." As Henry pointed out, once the valve seals were
broken on the Re-entry Control System, the system had the potential of
losing fuel and degrading. You wanted to land within hours, not days, of
activating the Re-entry Control System.

I heard the reason is that the thrusters used peroxide with a catalyst, and
that once used, the catalyst would start to break down.