Mission Elapsed Time (MET) is used by NASA during their space missions, most notably during their Space Shuttle missions. Because so much of the mission depends on the time of launch, all events after launch are scheduled on the Mission Elapsed Time. This avoids constant rescheduling of events in case the launchtime slips. The MET-clock is set to zero at the moment of liftoff and counts forward in normal days, hours, minutes, and seconds. For example, 2/03:45:18 MET means it has been 2 days, 3 hours, 45 minutes, and 18 seconds since liftoff.
The International Space Station (ISS) does not use an MET clock since it is a "permanent" and international mission. The ISS observes Coordinated Universal Time (UTC/GMT). When the shuttle visits ISS the ISS-crew usually adjusts their workday to the MET clock to make work together easier. The shuttles also have UTC clocks so that the astronauts can easily figure out what the "official" time aboard ISS is.
Famous quotes containing the words mission, elapsed and/or time:
“When you’re dealing with monkeys, you’ve got to expect some wrenches.”
—Alvah Bessie, Ranald MacDougall, and Lester Cole. Raoul Walsh. Captain Nelson, Objective Burma, giving a subaltern a mission (1945)
“The quickness with which all the “stuff” from childhood can reduce adult siblings to kids again underscores the strong and complex connections between brothers and sisters.... It doesn’t seem to matter how much time has elapsed or how far we’ve traveled. Our brothers and sisters bring us face to face with our former selves and remind us how intricately bound up we are in each other’s lives.”
—Jane Mersky Leder (20th century)
“Boys finding for the first time their loins filled with heart’s
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Widowed farmers whose hands float under light covers to find
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Arisen at sunrise”
—James Dickey (b. 1923)