Editing Time zone (section)

== Time in outer space ==
Orbiting spacecraft may experience many sunrises and sunsets, or none, in a 24-hour period. Therefore, it is not possible to calibrate the time with respect to the Sun and still respect a 24-hour sleep/wake cycle. A common practice for [[space exploration]] is to use the Earth-based time of the launch site or mission control, synchronizing the sleeping cycles of the crew and controllers. The [[International Space Station]] normally uses Greenwich Mean Time (GMT).<ref>{{cite web|title=Ask the Crew: STS-111|url=http://www.spaceflight.nasa.gov/feedback/expert/answer/crew/sts-111/index.html|publisher=National Aeronautics and Space Administration|date=June 19, 2002|access-date=September 10, 2015|archive-date=September 28, 2015|archive-url=https://web.archive.org/web/20150928070925/http://spaceflight.nasa.gov/feedback/expert/answer/crew/sts-111/index.html|url-status=dead}}</ref><ref>{{cite web|title=Day in the Life|url=http://spaceflight.nasa.gov/station/crew/exp7/luletters/lu_letter9.html|last=Lu|first=Ed|publisher=National Aeronautics and Space Administration|date=September 8, 2003|access-date=September 10, 2015|archive-date=September 1, 2012|archive-url=https://web.archive.org/web/20120901183936/http://spaceflight.nasa.gov/station/crew/exp7/luletters/lu_letter9.html|url-status=dead}}</ref>

[[Timekeeping on Mars]] can be more complex, since the planet has a solar day of approximately 24 hours and 40 minutes, known as a [[Sol (day on Mars)|sol]]. Earth controllers for some Mars missions have synchronized their sleep/wake cycles with the Martian day, when specifically solar-powered rover activity occurs.<ref>{{cite web |url=https://www.space.com/17815-mars-rover-jet-lag.html |title=New Tricks Could Help Mars Rover Team Live on Mars Time |author=Megan Gannon |website=Space.com |date=September 28, 2012}}</ref>