At orbital speed, spacecraft circle the Earth every 90 minutes, with a sunrise or sunset every 45 minutes, making it difficult to keep track of time as usual. Time in space is tracked more than one way. Astronauts sometimes wear more than one wristwatch, one set to Houston time and another set to mission time. This is a mission timer that is started at launch and stopped at landing. It shows how much time has elapsed since the mission began. Mission elapsed timers like this are located in the spacecraft and Mission Control Center, and also in the Press Center, so everyone knows how far into the mission they are, when scheduled events will happen, and when it's time to sleep and wake. Events that happen in space are typically recorded in mission elapsed time (MET). NASA gave this timer to the Museum when it was no longer needed on the Space Shuttle.
Display Status
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.
Object Details
Country of Origin
United States of America
Type
EQUIPMENT-Electronics
Manufacturer
LSI Avionic Systems Corp.
Dimensions
3-D: 13.8 × 10.1 × 8cm (5 7/16 × 4 × 3 1/8 in.)
Materials
aluminum, acrylic, velcro
Inventory Number
A20130074000
Credit Line
Transferred From NASA
Data Source
National Air and Space Museum
Restrictions & Rights
Usage conditions apply
For more information, visit the Smithsonians Terms of Use.