Lockheed Martin has completed thermal vacuum testing of the U.S. Navy\'s first Mobile User Objective System satellite. A next-generation narrowband tactical satellite communications system, MUOS will provide significantly improved and assured communications for mobile warfighters. It will augment and ultimately replace the current UHF system and provide 10 times more communications capability, including simultaneous voice, video and data. In tests in Lockheed Martin\'s Dual Entry Large Thermal Altitude chamber, the MUOS spacecraft was stressed in a vacuum environment at extreme hot and cold temperatures it will experience throughout its design life. The milestone was the culmination of an extensive test program that proves the spacecraft\'s overall design, quality of workmanship and survivability during launch and on-orbit operation environments, the company said. Lockheed said thermal vacuum testing of the first MUOS satellite was completed later than planned as the team worked to validate the performance of the state-of-the-art spacecraft. \"The team worked extremely hard to complete this important test phase in a disciplined and timely fashion to support our customer\'s launch needs,\" said Mark Pasquale, Lockheed Martin vice president and MUOS program manager. \"The test confirms the spacecraft\'s ability to provide critical on-the-move communications for our deployed forces in remote and rugged locations and represents a pivotal moment toward achieving mission success on this program.\" The first MUOS satellite, along with the associated ground system, is on track to launch early next year.