Today, nearly every person in America relies on satellites for one function or another. A majority of the population is dependent on Global Positioning System (GPS) satellites for their smartphones, which empower them to track their location and retrieve directions. Other satellites allow individuals to video-chat with contacts around the world, download information in remote locations, and even place satellite phone calls. The US military also relies on space-based capabilities. But it may not have the latest technology that's available in the general population.
The global security environment differs greatly from 10 years ago, with military forces facing a variety of threats at an ever-increasing pace. When equipped with the latest RF and microwave satellite technology, however, their defense capabilities are significantly enhanced. Utilizing commercial third-generation (3G) mobile technologies, Lockheed Martin has integrated technology used by the general public with military-specific needs. In doing so, it can offer warfighters enhanced, on-the-move communications capabilities.
In 2004, the US Navy awarded Lockheed Martin the next-generation narrowband tactical satellite-communications contract for the Mobile User Objective System (MUOS). MUOS will augment and replace the legacy Ultra High Frequency (UHF) Follow-On system (UFO), providing reliable communicationsincluding simultaneous voice, video, and datafor mobile warfighters. The program includes four geostationary Earth-orbit satellites with one on-orbit spare. A fiber-optic terrestrial network connects four ground stations. The system will provide mobile warfighters with point-to-point and netted communications services with a secure "comm on the move" capability.
MUOS will feature conversational and recognition voice services as well as mixed transport of voice and data services. At data rates of 64 kb/s and beyond, MUOS will be able to receive and transmit the following: low-data-rate telemetry; short digital messaging; imagery transfer; file transfer; electronic mail; remote computer access; remote sensor reception; sporadic messaging for distributed applications; video; and video teleconferencing. From the perspective of the warfighter, this system will be the difference between downloading the most up-to-date mission information versus relying on information previously received. It will be the difference between seeing what conditions are in real time versus relying on images that were taken earlier. This increased communications capabilitycoupled with the ability to remain in motionlimits the exposure of the warfighter in remote and potentially hostile environments. In doing so, it greatly increases mission success and personnel safety.
To bridge the gap between the current ultra-high-frequency (UHF) system and the new MUOS technology, the Lockheed Martin system features a dual-payload approach. MUOS satellites will employ both 3G wideband code division multiple access (WCDMA) and legacy UHF satcom payloads. By offering adaptive power control, the WCDMA waveform provides the required quality of service to each user while maximizing system capacity. MUOS uses Internet Protocol versions 4 and 6 (IPv4/IPv6) to give the warfighter global roaming connectivity to the Global Information Grid. These features will provide a 16-fold increase over legacy UHF satellite communications in the number and capacity of satellite links.
The architecture is designed for significant future growth as capacity demand increases. It offers opportunities for component makers to support Lockheed Martin and its teammates with upgrades as technology is developed. The first MUOS satellite (along with the associated ground system) is on track to support launch in the first quarter of 2012 (Fig. 1). The satellite has completed final factory testingincluding passive-intermodulation (PIM), electromagnetic-interference (EMI), electromagnetic-compatibility (EMC) testing, and spacecraft-level Final Integrated System Test (FIST) at Lockheed Martin facilities in Sunnyvale, CA (Fig. 2, Fig. 3, Fig.4).
Completion of PIM testing assures that intermodulation generated from the high-power satellite-downlink transmissions do not interfere with the extremely low-power signals uplinked from the legacy terminals used by the warfighter. The EMI and EMC testing ensures self-compatibility of the payloads on the satellite, as well as satellite compatibility with the launch vehicle's EM environment. For its part, FIST verified that the overall performance of the fully integrated MUOS spacecraft is compliant with the MUOS Performance Specification. It also established a performance baseline, which is compared to the Baseline Integrated System Test (BIST) data. These baselines serve as essential guidelines once the satellite is on orbit and post-launch performance is assessed.
Successful completion of environmental testing provides the MUOS team with high confidence in the functional capabilities of this next-generation communications satellite for launch and on-orbit operations with 100% mission success. The spacecraft is now in final preparations before it ships to Cape Canaveral Air Force Station, FL in December. It will launch aboard an Atlas V rocket early next year.
Soon to follow are MUOS SV-2 and SV-3, which are progressing steadily. They are currently undergoing environmental testing and assembly activities, respectively, to support the delivery of this vital technology at the earliest possible launch date. Clearly, the MUOS program is an example of how older programs are being replaced with vastly improved technologies and capabilitiesin this case, for the benefit of today's warfighters.
Mark Pasquale
Vice President and MUOS Program Manager
Lockheed Martin
www.lockheedmartin.com/muos