Contractors must submit bids to NASA by 1 p.m. ET Friday in seeking the contract to build the Ares I upper stage.

Ares is part of the Orion-Ares next-generation space vehicle that will replace the venerable space shuttle fleet. The new system will have a light version to loft crew members into space, and a heavier cargo version.

NASA last year awarded Lockheed Martin Corp. [LMT] the contract to build Orion, the crew exploration vehicle, and NASA this year will award the contract for the Ares rocket to lift Orion into orbit.