WASHINGTON—Jeff Bezos’s Blue Origin sued the U.S government over NASA’s decision to award a $2.9 billion lunar lander contract to Elon Musk’s SpaceX. Blue Origin said its lawsuit filed in the U.S. Court of Federal Claims on Friday is “an attempt to remedy the flaws in the acquisition process found in NASA’s Human Landing System.” It added it believes “the issues identified in this procurement and its outcomes must be addressed to restore fairness, create competition, and ensure a safe return to the Moon for America.” Last month, the Government Accountability Office (GAO) sided with the National Aeronautics and Space Administration over its decision to pick a single lunar lander provider, rejecting Blue Origin’s protest. Blue Origin’s lawsuit remains under seal. NASA must file a response to the challenge by Oct. 12. Blue Origin and defense contractor Dynetics have argued that NASA was required to make multiple awards. The GAO …