I was watching the movie Apollo 13, and one thing struck me as quite odd. According to Wikipedia,
[Movie director Ron] Howard went to great lengths to create a technically accurate movie, employing NASA's technical assistance in astronaut and flight controller training for his cast, and even obtaining permission to film scenes aboard a reduced gravity aircraft for realistic depiction of the "weightlessness" experienced by the astronauts in space.
However, around 63 minutes into the movie, during the command module shutdown scene, the movie shows the command module's guidance computer being shut down followed by mission control stating "computer off" and specifically confirming shutdown of the CM computer with indications on one of the big screens in the background that would appear to state that the telemetry values are out of range.
What I find weird is that even after the DSKY digital display is turned off and during the "Odyssey signing off" scene immediately following it, the CM computer DSKY shows the
STBY light seemingly turned on. According to Wikipedia, standby mode was originally designed for use in mid-flight and to reduce the CM computer's power consumption from 70 W to 60-65 W, though "in practice ... this feature was never used".
Obviously some things were changed for dramatic effect in the movie (for example, the apparent proximity in time between the cryo tank fans being turned on and the explosion, which in the movie is depicted as being on the order of a few seconds whereas in reality it took considerably longer), but this seems like a really silly mistake to make if one sets out to make a technically accurate movie.
- Was the CM guidance computer completely shut down following the accident on Apollo 13, or was it simply set to standby mode?
- If it was set to standby mode and the computer was designed to allow standby mode for long stretches of mid-course flight, why was this seemingly so much of a problem if (presumably) when needed the computer could relatively easily be powered back up for only a marginal increase in power drain for the short period of time it would be needed?
- Even considering NASA's desire to make it possible for the crew to operate the spacecraft (relatively) autonomously, was the Apollo CM even designed so that it was possible for the astronauts to fully power off such a critical system as the main guidance computer in the middle of the flight?