I don't know about the Kennedy or Johnson administration, but back in 2010, near the 41st anniversary of the first moon landing, somebody posted this on /r/history
http://www.lettersofnote.com/2010/11/in-event-of-moon-disaster.html
It is a memo from Nixon's speechwriter William Safire to H R Halderman, outlining what Nixon should say if the Apollo astronauts became stranded on the moon.