Blue Origin, the space rocket company backed by billionaire Jeff Bezos, is formally challenging the $2.9 billion moon lander contract awarded by NASA to rival Elon Musk’s SpaceX. Blue Origin said on Monday it had filed a protest with the federal Government Accountability Office, accusing NASA of moving the goalposts for contract bidders at the last minute. NASA early this month awarded SpaceX the contract to build a spaceship to deliver astronauts to the moon as early as 2024, choosing Musk’s company over Blue Origin and defense contractor Dynetics Inc. The sought-after project aims to put humans back on the moon for the first time since 1972. "NASA has executed a flawed acquisition for the Human Landing System program and moved the goalposts at the last minute", Blue Origin said in an emailed statement. "Their decision eliminates opportunities for competition, significantly narrows the supply base, and not only delays, but also endangers America"s return to the moon. Because of that, we"ve filed a protest with the GAO." Musk"s SpaceX bid alone while Amazon.com (AMZN.O) founder Bezos"s Blue Origin partnered with Lockheed Martin Corp (LMT.N), Northrop Grumman Corp (NOC.N) and Draper. The filing of the 50-page protest by Blue Origin was reported earlier by the New York Times.