Commercial Satellite Capacity Could Fill Potential UHF Gap

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  Space News Business

Commercial Satellite Capacity Could Fill Potential UHF Gap

By JEREMY SINGER
Space News Staff Writer
posted: 05 November 2007
02:57 pm ET





BOSTON —


Commercial satellite capacity leased from Loral Skynet appears to be the leading candidate to fill a gap in UHF-band mobile satellite communications coverage that some U.S. military leaders fear could materialize within the next three years.





Pentagon officials have grown




worried in recent years that some of the U.S. Navy’s UHF Follow-On (UFO)




satellites that are on orbit today may not last until the service begins launching the new-generation Mobile User Objective System (MUOS) satellites in March 2010. The geostationary-orbiting UFO satellites are used by mobile forces as well as headquarters staff in fixed locations




.

The most recent analysis




by the Navy’s Communications Satellite Program Office in San Diego




estimates there is a less-than-70 percent chance that the full UHF Follow On constellation will be healthy between December 2008 and when the MUOS satellites begin launching,




according to Steven Davis, a spokesman for the Space and Naval Warfare Systems Command in San Diego.

Options for filling any coverage gap that might materialize




include leasing commercial UHF services, and adjusting the Navy’s




remaining




constellation




, Davis said Oct. 25 in a written response to questions




.

Citing classification restrictions, U.S. Navy Lt. Denver Applehans, a spokesman for U.S. Strategic Command in Omaha, Neb., declined to comment on whether




a degradation of the UFO constellation would leave certain areas of the




globe without coverage or simply reduce the amount of




bandwidth available worldwide.

U.S. Air Force Gen. Kevin Chilton, commander of




Strategic Command, was briefed on the gap concerns




Oct. 18, Applehans said Oct. 26 in a written response to questions. One option under consideration – and likely the only one feasible prior to the first MUOS launch – is leasing UHF services from satellite operator Loral Skynet of Bedminster, N.J., beginning in 2008, Applehans said.

Another option is




leasing a payload aboard a spacecraft operated by Intelsat of Washington that would be available




around 2010, Applehans said.

Still another option is




a concept called




Netted Iridium




that Iridium Satellite LLC of Bethesda, Md., has demonstrated with the Marine Corps. However, that capability will




not be available until around the time of




the first MUOS launch, he said.

Iridium operates a global constellation of 66 satellites in low orbit. Scott Scheimreif, assistant vice president for government programs at Iridium, said




the




Netted Iridium




concept enables mobile forces to communicate over ad-hoc networks and




includes a push-to-talk feature




. A prototype of this system




has seen limited




use in Iraq, he said.





Iridium is




negotiating




a five-year contract with the Marine Corps that could lead to improvements




including better access, range and signal security, Scheimreif said. In the interim, however, the prototype network could be expanded to help fill any UHF Follow On gap, he said.





Strategic Command also has




asked the Pentagon’s newly established




Operationally Responsive Space program office




to look at gap-filler options




, Applehans said.




But the type of system typically associated with Operationally Responsive Space, a relatively small satellite built and launched on relatively short notice, probably would not fill the military’s needs in the desired time frame, he said.







Applehans
said




such systems have yet to demonstrate the ability to meet troops’ coverage and capacity needs. Small




satellites like the ones being developed under the Pentagon’s experimental




TacSat
series might not able to handle software algorithms that increase the number of troops who can access a single communications channel, a technique




used on the UHF Follow On system




today. “This time division algorithm needs a stable platform in a specific orbit to be effective and it is unclear if a TacSat can meet this requirement,” he said.



However, the military may gain insight that can be applied to future use of small satellites to augment communications coverage through the planned TacSat-4 experiment, Applehans said. That spacecraft is expected to launch in late 2008.





In a written response to questions, Col. James Haywood, Air Force deputy director for space acquisitions, said the Operationally Responsive Space program office received a cost estimate of around $60 million to build a small satellite to help fill the potential UHF gap, but added that the figure had not been independently validated. Other options that the office looked at to address the gap included aerial platforms like balloon relays, he said.