Lockheed Martin (LMT 0.10%) landed a sizable contract award from the U.S. Air Force Thursday, announced as part of the Department of Defense's daily summary of contracts awarded last night.

The contract in question, a $45.6 million modification to an existing contract, instructs Lockheed to perform "Rapid Repair and Response legacy repair" work on Lots 3, 4, and 5 of the C-5 Reliability Enhancement and Re-engining Program (RERP ).

The RERP program aims to modernize the Air Force's fleet of Lockheed C-5 Galaxy transport aircraft by upgrading them with new General Electric (GE -0.07%) F138-GE-100 jet engines -- an analog to the CF6-80C2 engines that power Air Force One, as well as many Boeing (BA 3.03%) 747 and 767 commercial jets. With better engines, the Air Force hopes to improve the C-5's "mission capability rate" by as much as 20 percentage points to 75%, allowing the planes to spend more time in service, and less time in the repair shop. It is also hoped that the upgraded planes will be able to carry more cargo (in excess of 270,000 pounds) and take off and land on shorter runways (as short as 5,000 feet).

Thursday's contract modification lifts the value of the RERP program for Lockheed to nearly $3.7 billion in total. Lockheed's work on this latest installment of the program should be complete by Oct. 29, 2014.