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We'll need far more spacecraft to figure out if anything living lies under the crust of these worlds, but in the meantime, Antarctica serves as a handy analog to figure out the limits of life.

Every time an Apollo astronaut walked off the moon and into his spacecraft, he tracked a load of dust with him.

But getting any sauce at all is a privilege of her position, one that few others on the spacecraft are afforded.

Throughout their mission there have always been spacecraft attached to the space station to get them - and the rest of those onboard - home if there was an emergency.

This week, four astronauts took off to the ISS, where the spacecraft will pick up Williams and Wilmore before returning home.