SpaceX's first crewed mission is headed back to Earth. Here's every step that must go perfectly for 2 NASA astronauts to come home safely.

NASA, SpaceX, and two veteran astronauts are about to finish the first-ever crewed commercial spaceflight. On Saturday, astronauts Bob Behnken and Doug Hurley are scheduled…

Read More SpaceX's first crewed mission is headed back to Earth. Here's every step that must go perfectly for 2 NASA astronauts to come home safely.