Lockheed Martin Space Systems of Sunnyvale, Calif., completed thermal vacuum testing April 25 on the U.S. Navyโ€™s second Mobile User Objective System (MUOS) communications satellite, the company announced in a June 18 press release.

The testing validates satellite performance in a simulated space environment. MUOS-2 was exposed to temperature extremes during the testing, carried out inside Lockheed Martinโ€™s Dual Entry Large Thermal Altitude chamber, according to the press release.

MUOS-2 is scheduled for launch in early 2013.

โ€œWith the completion of environmental testing, the MUOS team has illustrated its continued focus on successful program execution and mission success,โ€ Kevin Bilger, Lockheed Martinโ€™s Global Communications Systems vice president and general manager, said in a prepared statement. โ€œThe first MUOS satellite is on-orbit and poised to provide significantly improved communications capabilities for the mobile warfighter.โ€

MUOS-1 was launched Feb. 24 from Cape Canaveral Air Force Station, Fla., aboard a United Launch Alliance Atlas 5 rocket. The Navy expects the MUOS constellation, consisting of four satellites plus an on-orbit spare, to reach initial operational capability in 2015 and provide narrowband service beyond 2025.