Back in the 1970s, how did NASA describe when an event happened during a mission?

For example, when Mariner 10 did its fly-by of Venus, how did the Mariner team refer to that moment in time? Did they use the ordinary date and time from a particular timezone on Earth? Did they count some number of elapsed seconds since the start of the mission?

(Apollo 11, in 1969, appeared to use elapsed days/hours/minutes/seconds from the start of the mission, at least according to transcripts.)


For manned missions, everything was usually tracked in Mission Elapsed Time in days, hours, minutes, and seconds.

I don't know if longer term unmanned interplanetary missions did the same -- they might "re-base" time as they approach a target and use, for example, expected time of closest approach to Jupiter as a reference time, so "PJ -1:00:00" could refer to one hour before closest approach.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.