WASHINGTON (REUTERS) - Blue Origin, the space rocket company backed by billionaire Jeff Bezos, is formally challenging theUS$2.9 billion (S$3.8 billion) moon lander contract awarded by Nasa to rival Elon Musk's SpaceX.

Blue Origin said on Monday (April 26) it had filed a protest with the federal Government Accountability Office, accusing Nasa of moving the goalposts for contract bidders at the last minute.