What is SpaceX? How does it make money?
The company is set to make history as, alongside Nasa, it send two astronauts to the International Space Station – the first time a private company has done this.
The launch from the Kennedy Space Centre in Florida is scheduled for 16:33 local time (20:33 GMT / 21:33).
Science correspondent Laura Foster takes a closer look at the company’s aims.
source: bbc.com