U.S. Navy Launches Third MUOS Satellite
WASHINGTON – The U.S. Navy launched the third satellite in its next-generation mobile communications system Jan. 20, but service officials said the constellation’s primary capability – to provide smartphone-like services – would not be available until the end of the year.
The multibillion-dollar Mobile User Objective System ultimately will consist of four geostationary-orbiting satellites plus one on-orbit spare, and four ground stations. Built by Lockheed Martin Space Systems of Sunnyvale, California, the MUOS constellation is designed to provide smartphone-like communications to mobile forces at rates 10 times faster than the legacy system.
The MUOS-3 satellite was launched aboard a United Launch Alliance Atlas 5 rocket from Cape Canaveral Air Force Station, Florida, at 8:04 p.m. Eastern time. The Atlas 5 configuration used in the launch featured a 5-meter payload fairing, five solid-fueled strap-on boosters and one RL-10 Centaur engine, the fifth time such a setup has been used.
In a press release issued late Jan. 20, Lockheed Martin reported that the satellite had been safely delivered to geostationary transfer orbit and was responding to commands. The release said the satellite would take nine days to reach geostationary orbit 36,000 kilometers above the equator, after which it will be undergo testing before being turned over to the Navy.
The first two MUOS satellites launched aboard Atlas 5 rockets in February 2012 and July 2013.
Like the Navy’s legacy UHF Follow On satellites, the MUOS satellites are equipped with a UHF-band narrowband payload to provide links to ships at sea and to mobile ground forces operating in hard-to-reach areas such as beneath dense forest canopies. The smartphone capability to be introduced by MUOS is provided by a digital payload employing a technology standard known as wideband code division multiple access, or WCDMA.
To date, only the UHF payloads aboard the MUOS satellites have been utilized, a situation that is not expected to change until the end of the year.
“This provides bridge capability for the existing seven Ultra High Frequency Follow-On satellites that are still providing service,” Steve Davis, a Navy spokesman, said Jan. 19. “The full suite of MUOS services that the WCDMA payload offers should be available to end-users later this year after system operational testing by the Department of Defense.”
In a report delivered to congressional defense committees in October, the Navy said a final operational test of the WCDMA payload was rescheduled for December 2015 because of issues integrating the satellites’ waveform, ground system and radio terminal software. The report said that after initial tests in April, “system performance indicated more time was needed to mature” the capability of the digital payload before successful certification. Specifically, the report said, the system had reliability issues.
The MUOS program is expected to cost about $7.4 billion, according to the Government Accountability Office. Each satellite covers about one-third of Earth’s surface. The initial constellation is expected to provide service through 2025.
The Navy has not announced a next-generation program to follow MUOS. However, when the service reserved the UHF-band frequency for the first block of MUOS satellites, it also reserved frequency for a follow-on program consisting of another five satellites.
Capt. Joe Kan, the Navy’s MUOS program manager, said the next step would most likely be an analysis of alternatives that would begin in a year or two. Given that the final MUOS satellite is slated to launch next year, that means the existing production line likely will close down, thus limiting any economic advantages to extending the program versus going with brand new system.