SpaceX is set to mark a huge milestone in its own company history, with a first-ever crewed spaceflight set to take off from Cape Canaveral in Florida later today. The mission is Commercial Crew Demo-2, the culmination of its Crew Dragon human spacecraft development program, which will carry NASA astronauts Doug Hurley and Bob Behnken to the International Space Station.


This is the first U.S.-based human rocket launch since the end of the Space Shuttle program in 2011. NASA undertook the Commercial Crew program in 2010 to seek public-private partnerships to return its launch capabilities, eventually selecting both NASA and Boeing to design and develop spacecraft rated for human flight. SpaceX is the first from this program to make a crewed launch attempt.

But perhaps most significantly, it is the first time in 17 years that anyone has launched a new type of spaceship to carry humans to Earth orbit (see ‘How humans have reached orbit’). “This is a whole new way of sending people to space,” says Robert Cabana, a former NASA astronaut who is now director of the Kennedy Space Center in Florida.