Lockheed Martin [LMT] completed thermal vacuum testing on the fourth satellite scheduled to join the U.S. Navy Mobile User Objective System (MUOS) constellation, the company said on Dec. 1.
This fourth satellite is designated MUOS-4 by the Navy.
The testing of MUOS-4 was concluded on Nov. 12 inside the Dual Entry Large Thermal Altitude chamber at Lockheed Martin’s Sunnyvale, Calif., satellite integration facility. MUOS-4 is set to advance to final integrated system testing before launching in the second half of 2015.
“The successful completion of thermal vacuum testing assures that MUOS-4 can endure the extreme hot and cold temperatures it will experience throughout its on-orbit mission life,” Iris Bombelyn, vice president of Lockheed Martin’s Narrowband Communications mission area, said in a statement.
Once it is launched into orbit, MUOS-4 is expected to complete the operational constellation and provide global coverage of secure mobile satellite communications.
Lockheed Martin is under contract to produce five MUOS spacecraft, with MUOS-5 planned to launch in 2016.
MUOS-3 was transported to Cape Canaveral Air Force Station on Nov. 5, MUOS-2 was launched in 2013, and MUOS-1 was launched and became operational in 2012.