Elon Musk's space venture could be cleared to launch satellites for the Pentagon by Dec. 1, a senior U.S. Air Force official said Tuesday, hours before the firm won a government deal worth up to $2.6 billion to build and operate space taxis.

The planned certification of the Falcon 9 rockets used by Mr. Musk's Space Exploration Technologies Corp., or SpaceX, would allow the firm to challenge the near monopoly for national security satellite launches enjoyed since 2006 by a joint venture between Boeing Co. and Lockheed Martin Corp.

SpaceX has been involved in a fierce lobbying battle with the United Launch Alliance LLC, or ULA, joint venture and the Pentagon to win military work. It sued both earlier this year in an effort to break up an existing multiyear deal involving ULA and enter the market itself more quickly.

The prospect of competition in space launches has been energized by concerns that ULA's reliance on Russian-made rocket engines could leave some U.S. military and spy satellites grounded if the venture can't secure more supplies or spares. ULA has said it has enough engines to last two years and received a new shipment in August. The Pentagon is exploring the development of a new, totally U.S.-made rocket engine.

"I'm rooting for SpaceX to come into the competition," said Gen. John Hyten, the new head of Air Force Space Command, in a speech at an industry conference near Washington, D.C.