The launch of a SpaceX Falcon 9 rocket and Crew Dragon capsule, carrying NASA astronauts Doug Hurley and Bob Behnken into space, is scheduled for 4:33 p.m. EDT today. Though Elon Musk's space exploration company has been doing cargo runs to the International Space Station since 2012, this launch marks the first time a private company has attempted to fly humans to space. It is also the first manned launch from the United States since the space shuttle program ended in 2011.