How long can an astronaut stay in ISS?

"Can"?  We don't know.  Typically crew members stay for about six months.  This March, however, we will launch an astronaut (Scott Kelly) and a cosmonaut (Mikhail Kornienko) that will stay there for a full year.  By studying how they react in those second six months, we will gather more data that will help us understand how a two year journey to Mars will affect crew members.    Both Scott and Mikhail have previously spent 6 months aboard ISS.  Scott has a twin brother who is also an astronaut.  He will be studied on the ground as a control.

The record for a single stay in space was made 20 years ago, aboard the space station Mir.  Cosmonaut Valeri Polyakov was there for 437 days.

Read other answers by

Robert Frost on Quora:

• What are the procedures when astronauts on the ISS are in danger from debris?
• Why is the International Space Station not placed above the atmosphere to stop the need for regular boosts to stay in orbit?
• How much velcro is used on the ISS, in light of the Apollo 1 fire? When did it "come back" into use?

from Quora http://ift.tt/2dJr6s7