WASHINGTON – The U.S. Defense Department has told a consortium of three companies, including propulsion provider Aerojet Rocketdyne, that the government does not own the design or production rights to United Launch Alliance’s Atlas 5 rocket, a ruling that would appear to thwart an early effort to add another competitor to the launch business.

In May, the consortium asked the Secretary of Defense about the possibility of obtaining production rights to the rocket, a military workhorse that ULA plans to replace by the end of the decade.

In theory, the consortium would use the Aerojet-designed AR1 engine to replace the controversial Russian-made RD-180 engine used on the Atlas 5 today.

But the Defense Department said it did not own the design or production rights for the rocket, nor did it own the intellectual property rights, according to a June 19 statement from Capt. Annmarie Annicelli, an Air Force spokeswoman.

Lockheed Martin and ULA say they own different elements of the Atlas 5 design. According to Annicelli, ULA also owns the Atlas 5 production facility in Decatur, Alabama, and the launch pads and towers at Cape Canaveral Air Force Station in Florida and at Vandenberg Air Force Base in California.

ULA officials had previously said the company has “no intention of selling or transferring” Atlas 5 production rights.

Besides Aerojet Rocketdyne, the consortium that inquired about Atlas 5 production rights includes Dynetics, of Huntsville, Alabama, and Shafer Corp. of Arlington, Virginia, which is led by former NASA Administrator Mike Griffin.

Mike Gruss covers military space issues, including the U.S. Air Force and Missile Defense Agency, for SpaceNews. He is a graduate of Miami University in Oxford, Ohio.