SpaceX announced today that it is filing a legal challenge to the U.S. Air Force’s latest Evolved Expendable Launch Vehicle (EELV) contract with United Launch Alliance (ULA), a joint venture of Boeing and Lockheed Martin. The long-term contract, which guarantees the purchase of 36 rocket cores from ULA to be used in national security launches, was granted to ULA on a sole-source basis without any competition from other launch providers. SpaceX is seeking the right to compete for some of these same launches.