To replicate true zero gravity conditions without actually going to space, would-be astronauts usually have to take parabolic flight. But sometimes, as Brien explains, they have to go in the opposite ...

When it comes to designing spacecraft and preparing astronauts for life in zero gravity, the ocean is the best testing environment on this side of the stratosphere. One of the most useful similarities ...

Someday Elon Musk might manage to pack enough of us lowly serfs into one of his super rockets that we can actually afford a ticket to space, but until then our options for experiencing weightlessness ...