|
SPACE TECHNOLOGY
July 2007
Navy Upbeat About Communications Spacecraft,
Despite
Radio Troubles
By Sandra I. Erwin
 The Navy is building a dazzling satellite constellation that promises frontline troops and sailors at sea access to a multimedia wonderland.
But while the satellites are on a fast track toward a 2009 launch, the tactical radios that ground troops would need in order to receive the spacecraft’s digital signals may not be ready on time.
The $6 billion mobile user objective system, or MUOS, is scheduled to replace aging ultra-high frequency communications satellites that, by information-age standards, are severely outdated. The new system will offer voice, data and video services.
Unlike other big-ticket space programs in the Defense Department, the MUOS spacecraft, military officials said, are on course to meet their launch deadlines and have not experienced cost overruns.
One unforeseen glitch, however, emerged in recent months, when program officials realized that the portable digital radio terminals that are required to receive the MUOS signals will be taking much longer than previously anticipated.
When the MUOS program got under way in 2004, the plan was for the terminals to be developed as part of the Defense Department’s Joint Tactical Radio System. The JTRS program would deliver handheld and backpack-size radios, as well as larger terminals for ships and aircraft, that could be programmed to run the MUOS software. But JTRS has been derailed by a series of technical setbacks, budget cuts and Pentagon turf battles.
The Army — expected to be the largest user of MUOS communications services — earlier this year decided to curtail funds for the JTRS MUOS terminals, which effectively will delay the project by several years.
As a result, the JTRS program office published a solicitation in late May, that sought industry proposals for an “interim” radio that could be programmed to operate the MUOS waveform. Contractors were asked to submit “white papers” by June 4.
MUOS program officials at the Space and Naval Warfare Systems Command in San Diego said they are hopeful that the Army will be able to acquire new radios by the time the first MUOS satellite reaches orbit. Ground troops, including soldiers and Marines, account for 85 percent of the users of ultra-high frequency satellite communications.
While the Air Force oversees most of the Defense Department’s space systems, the Navy is responsible for narrowband satellite communications. UHF is the only radio frequency that can penetrate clouds, foliage and urban structures.
The MUOS constellation was designed to replace the Ultra High Frequency (UHF) Follow-On satellite system currently in operation. Two of the Navy’s 10 UHF Follow-On satellites broke down and went out of service — one in June 2005 and the other in September 2006. The Navy said it can continue to provide adequate service with the remaining eight satellites but still worries that capacity will be running short, at least until the first MUOS satellite is fully operational in 2010.
“MUOS is critical to satisfying the demand for tactical satellite communications,” said Vice Adm. James D. McArthur Jr., head of the Naval Network Warfare Command.
In recent combat operations in Iraq and Afghanistan, the UHF satellites were only able to support 80 percent of the narrowband tactical satellite communication requirements, McArthur told the Senate Armed Services subcommittee on strategic forces.
The full constellation of four MUOS satellites — built by Lockheed Martin Corp. — will be deployed by 2014, said Navy Capt. David B. Porter, program manager for communication satellites at the Space and Naval Warfare Systems Command.
One satellite will have the same capacity as two of the current spacecraft, Porter explained in an interview. Each MUOS will carry two major components — a “legacy” payload that replicates the functions of the existing UHF Follow-On satellites and a W-CDMA bus, which features the advanced communications technologies that commercial vendors offer in third-generation multimedia cellular phones.
While the existing UHF Follow-On satellites can process 2.5 megabits of data per second, the W-CDMA (Wideband Code-Division Multiple-Access) technology delivers 40 megabits per second.
It would be unreasonable to draw comparisons between MUOS and commercial systems, since no commercial systems operate in the UHF spectrum. According to Porter, the closest similarity is Inmarsat or ACES, which are regional systems that operate in the L-band. “MUOS is taking advantage of the advances in commercial satellite services, while still providing the users the more robust performance that the UHF spectrum inherently offers the war fighter,” Porter said.
Four earth stations — in Italy, Australia and the United States (Hawaii and Virginia) — will serve as communications hubs for the MUOS system. Each will be equipped with three 60-foot diameter reflector antennas.
The military users of the MUOS network, however, only will be able to take advantage of the W-CDMA technology if they have modern radios that can operate the MUOS software. Until the new receivers are available, troops will have to stick with their existing terminals, which only can communicate with the legacy payload that will be aboard the MUOS satellites.
Another source of uncertainty in the program is whether and when the Defense Department will fund the “teleport” connections that are required for MUOS users to access the Pentagon’s proprietary networks (SIPRNET, NIPRNET and DSN).
The teleport connections are relatively easy to implement but, so far, the effort has not been funded by the Defense Information Systems Agency, Porter said. He said he is confident that the agency will budget for these technologies in fiscal years 2009 or 2010.
The teleport connections and the user terminals are two major concerns in the program today, Porter said. “It’s problematic that the JTRS program is not completely synchronized and the teleports aren’t funded.”
“The war fighters are very concerned” about the prospect of not having the advanced software-programmable radios, and of having to continue to operate legacy terminals, Porter said. He is optimistic, however, that contractors will be able to supply interim radios to fill the void. Current Navy and Air Force radios — the Digital Modular Radio and the ARC-210 — will be able to process the new MUOS waveform, Porter said. But none of the existing handheld or manpack radios is equipped to run the software.
“Several companies have expressed interest in providing handheld terminal for the new MUOS waveform,” Porter said.
Several of the Defense Department’s UHF radio suppliers — such as Harris RF Communications, the Raytheon Company and ViaSat — are expected to bid for the interim radios. The “request for information” specified that the desired terminals “should meet commercial standards, pass National Security Agency certification, and be rapidly fielded.” They also must be compliant with the Defense Department’s so-called Software Communication Architecture, use upgradeable embedded encryption and be built with an “open architecture.”
One word of advice from Porter is that contractors should “keep it simple.” The JTRS terminals ran into trouble because they were expected to process multiple software applications from a single box, which is tough to do in a handheld device. MUOS ground users want the radios to be light and easy to use, no larger than an Iridium satellite phone. “Mobile war fighters can’t move large antennas around,” Porter said.
Even though the JTRS program office categorized these terminals as “interim,” they most likely will be in operation for many years. Given the current disarray in the JTRS program, insiders said, it is unlikely that the military services will fund an interim radio and a yet-to-be developed JTRS terminal.
Government Accountability Office investigators concluded in a recent report that the “problems encountered under the JTRS program have resulted in deferrals of requirements and have increased the risk that MUOS capabilities will be underutilized until MUOS-compliant terminals are fielded.”
The report also warned about the potential for “significant cost and schedule growth risks” in the ground software development. “According to the program office, development of MUOS ground software represents one of the highest risks to the program due to the size and complexity of the contractor’s design,” noted GAO.
Porter said the risks highlighted by GAO are manageable. “We are leveraging a lot of commercial software,” he said. The lead contractor in charge of the ground stations is General Dynamics, which was selected by Lockheed Martin in 2005, and is working under an $830 million contract. The company is adapting the Ericsson universal mobile telecommunications system that is used by commercial cell phones.
“We are modifying the W-CDMA waveform” for military use, Porter said. “The software coding is not a trivial task. For MUOS we are taking commercial software for a military telecom system. Some programs get in trouble because they take commercial code and use it for a different application. In MUOS that is not the case because we are using the same application as the commercial system … It’s complex nonetheless,” he said. “So far, we are on schedule, on cost.”
Please email your comments to SErwin@ndia.org
Back To Top
|
Search Tips
