Assertion: astronaut's time | /r/HasProperty | spent on the planet
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text: Astronauts already spend extended periods of time on the International Space Station—the record is almost 438 days, set by a Russian cosmonaut in the mid-’90s, and U.S. astronaut Scott Kelly just embarked on a yearlong stay in space —but a trip to and from Mars would take about 14 months (not including time spent on the planet), and there wouldn’t be other visiting spacecraft that could bring an ailing astronaut (or dead body) back to Earth.