On Friday, the U.S. Department of Defense announced it has awarded Lockheed Martin (LMT -0.20%) a $1.9 billion contract modification to pay for "space vehicle five and six production launch operations."

The award refers to an Air Force Space and Missile Systems Center contract originally announced in January, whereby SMC said it intended to purchase and launch its fifth and sixth Advanced Extremely High Frequency (AEHF) communication satellites servicing the armed forces  of the U.S., U.K., Canada, and the Netherlands. In its January announcement, SMC clarified that only the "incumbent Prime developer" (Lockheed) is deemed capable of performing the AEHF work.

SMC's first two AEHF satellites are already in orbit. Two more are expected to launch between now and 2017. Satellites nos. 5 and 6 will go up subsequently, and a further seventh and eighth satellites are also anticipated.