Aside from physically training for the longest crewed missions that the United States had ever attempted, the actual training program was developed simultaneously with the hardware and experiments for the mission.
In the White House, President Nixon was very concerned for the Apollo 13 crew. Since Apollo 8’s successful lunar orbit, just one month before his inauguration, Nixon had developed a fascination with moon flight and a special admiration for the crew of that first circumlunar trip.
There was now cause for optimism in Mission Control. At the TELMU station, where the Lunar Module’s environmental signs were being continually monitored, the readings of the carbon dioxide concentrations aboard Aquarius were steadily dropping all day long.
Jack Lousma – One of the Capcoms for Apollo 13
Vance Brand (standing right) another Capcom for Apollo 13