The test follows years of development and delays as the US seeks to revive its human spaceflight program through private partnerships.
NASA awarded $4.2 billion (£3.23 billion) to Boeing and $2.5 billion (£1.9 billion) to SpaceX in 2014 to develop separate capsule systems capable of ferrying astronauts to the space station from US soil for the first time since NASA’s space shuttle program ended in 2011.
The space agency has since relied on Russian Soyuz spacecraft for trips to the orbiting space station.
During the test the SpaceX Falcon 9 rocket’s boosters will shut down approximately 12 miles (19km) above the ocean, a mock failure that will trigger Crew Dragon’s so-called SuperDraco thrusters to jet itself away at supersonic speeds of up to 1,500mph (2,400kph).