Laser Links in Space

Jan. 1, 2008

US forces have a pressing need for greater communications power. On that, military space officials and combatant commanders agree. Bandwidth is critical to functions ranging from voice and data links for fielded forces to the dissemination of the photos and other intelligence data gathered by aircraft.

The Air Force may not be able to satisfy all bandwidth needs—at least for the near future—but it will take a huge step toward that goal with launch of the Transformational Satellite Communications System around the middle of the next decade.

TSAT (pronounced “tee sat”) is being developed—and paid for—by the Air Force. Without it, other developmental projects such as the Army Future Combat Systems will not come close to delivering on their potential.

Boeing and Lockheed Martin are leading teams competing for the TSAT prime contract, which could be worth up to $15 billion, according to the Air Force. That money covers up to five satellites and a ground spare, as well as the required command and control infrastructure.

The TSAT concept dates back to late 2001, when senior military leaders were looking for ways to dramatically increase the communications bandwidth available to troops deployed in remote areas such as Afghanistan.

A Boeing illustration of the TSAT. (Boeing illustration)

The concept caught on quickly with military commanders eager for more bandwidth to receive data from the unmanned aerial vehicles that were proving valuable during combat in Operation Enduring Freedom.

The number of UAVs in use has since exploded, as has the use of bandwidth-hogging full-motion video. Military bandwidth demand is now typically referred to as insatiable.

At that point, the Defense Department looked at possibilities that included launching the satellites—originally referred to as Advanced Wideband—as early as 2007 or 2008. That date has slipped several times for several reasons, including Congressional budget cuts.

Budget issues—originating both on Capitol Hill and within the Pentagon—led to the Air Force a year ago moving the planned launch date from 2014 to 2016.

The Air Force began its work on TSAT at a time when most of its space acquisition portfolio was plagued by cost overruns and schedule delays. Service officials, mindful of the lessons learned from programs that went wrong, have taken steps to avoid repeating the same mistakes with TSAT.

One of the strategies is to use the block acquisition approach championed by Ronald M. Sega during his tenure as Air Force undersecretary between 2005 and 2007. In keeping with this philosophy, the Air Force does not seek to field all the new capabilities envisioned with TSAT on the first satellite.

Bite-Size Chunks

As Air Force Gen. Kevin P. Chilton, commander of US Strategic Command, noted during an Air Force Association symposium last September, USAF won’t wait until it gets “the whole enchilada right” to field TSAT.

Chilton, who was commander of Air Force Space Command at the time of those remarks, said the service will instead develop the system “in bite-size chunks” that offer incremental improvements.

“We’d like to provide an infrastructure where [troops] don’t have to worry about command and control information,” said Richard D. Pino, the Air Force TSAT program director at the Space and Missile Systems Center in Los Angeles.

The Advanced Extremely High Frequency Satellite Communications System satellites will help in this regard, as they offer a tenfold increase in secure communications bandwidth over the current Milstar satellites. However, TSAT goes even further, with a tenfold increase above the capability of Advanced EHF.

Workers put the final touches on a Milstar payload just before it is fitted atop a Titan IV B launch vehicle. (Lockheed Martin photo)

“Since enemies know our dependence on [satellite-based communications] and the fact that we’re using satellite communications for everything under the sun, you can expect enemies of the future to be attempting to disrupt, interfere, and exploit our communications links any way they can,” said Leonard F. Kwiatkowski, a retired Air Force brigadier general who now works as vice president and general manager of military space programs at Lockheed Martin Space Systems. “Advanced EHF, and then TSAT, have a leap ahead in security to stay ahead of the game.”

TSAT will offer a low probability of detection and intercept, so enemies should have difficulty knowing that US forces are in the area by picking up radio signals, Kwiatkowski said.

“The enemy will have a hard time seeing that we’re communicating, much less figure out what we’re doing,” he said.

The first two TSAT satellites are considered Block I, and the four that follow are Block II, according to Pino.

While the first two blocks are similar in functionality, the capability increases dramatically on the second, he said.

Another key element in the plan to build a solid foundation for the TSAT program is risk reduction work. A large amount of risk reduction has been performed in the early stages of the program, according to Gary E. Payton, deputy undersecretary of the Air Force for space programs.

Satellite programs such as the Space Based Infrared System (SBIRS) missile warning effort, which has seen its cost skyrocket by a factor of five since its inception, “were awarded in the late 1990s under the philosophy that you have a competition amongst the prime contractors, and you select the best of the competitors, and sort of let them do it,” Payton said in October.

No Cheap Fix

For TSAT, the government has sought to ensure that the key technology is mature before it awards the prime contract. Doing so has not been cheap, Payton noted, as the Air Force has funded this work by Lockheed Martin and Boeing to the tune of roughly $500 million each.

“But once we start with full-scale development on TSAT, we will have a much higher confidence, because our departure point is based on proven subsystem technology,” Payton said. “That’s a huge difference in a program’s start-up architecture.”

A Global Hawk in flight. ( Northrop Grumman photo)

Kwiatkowski, who once served as program director for the Military Satellite Communications Joint Program Office at Los Angeles AFB, Calif., called the level of Air Force investment in maturing the TSAT technology “unprecedented.” He could not recall a space program that had received a similar degree of investment prior to prime contract award.

“That gives us confidence that we’re ready to move into the next phase,” Kwiatkowski said in October.

In order to pass huge amounts of bandwidth quickly, TSAT relays data from one satellite to another via laser cross-links. This has been one of the two major areas of focus for the roughly $1 billion in risk reduction investment over the past several years.

Most communications satellites pass data over long distances through radio frequency connections to ground nodes. This is slower and introduces ground infrastructure vulnerable to enemy attack.

The secure communications satellites that precede TSAT—Milstar and Advanced EHF—use cross-links to avoid this vulnerability, but rely on radio frequency, which lacks the speed and capacity of lasers.

The Defense Department has experimented with laser satellite links in the past with the National Reconnaissance Office’s GeoLITE spacecraft. It exchanged information with other government satellites during a demonstration in 2001. However, TSAT will represent the first operational use of this technology.

The speed with which TSAT will pass data is staggering, particularly when compared with the first block of Milstar secure communications satellites.

An air tasking order that would have taken an hour to send in 1994 over Milstar will take less than a second with TSAT.

A reconnaissance aircraft’s high resolution image that would have taken nearly a day to send will take less than a second.

A radar image from a Global Hawk that would have taken nearly five days to transmit would also take less than a second.

Unlike Milstar, TSAT won’t just serve troops in fixed sites or those who have stopped and erected antennas (and become more vulnerable targets in the process), according to John Peterson, Boeing’s TSAT program manager.

While the military has some satellites that equip mobile forces with a limited communications capability, those satellites don’t approach the capacity envisioned for TSAT. The next generation constellation will enable troops to have Internet capabilities comparable to someone at a desktop computer. This connection will still be available while driving 35 to 45 miles per hour, Peterson said in October.

Even the next generation of mobile communications satellites that the Navy plans to launch in late 2009 offers “no comparison” with TSAT, Pino said.

This speed will dramatically change the intelligence picture for troops on the battlefield, Peterson said.

TSAT will allow troops to receive so much relevant data that they will view the battlefield like a quarterback who can determine the precise location of opposing defenders, know who may have fallen down or be otherwise out of position, and react quickly to find an open receiver, he said.

Simulations of battles in areas such as Korea and Southwest Asia indicate that this capability could help significantly reduce US casualties, Peterson said. It will also boost the precision of US strikes—leading to a considerable reduction in collateral damage, he said.

The Global Hawk’s hangar—the type of large, detailed image that will zip through TSAT. ( Northrop Grumman photo)

While the discussion on TSAT’s advanced capabilities often focuses on the benefits to ground forces, Kwiatkowski noted that the increased speed and capacity will benefit nearly every area of Air Force operations. TSAT will provide previously unobtainable intelligence products to airmen flying missions ranging from air cargo to close air support.

The other key technology that the Air Force and its contractors have worked to mature for TSAT is the Internet protocol (IP) router that some program officials refer to as “the brains of TSAT.”

Troops communicating over most satellites today need to set up circuits; TSAT will enable them to easily plug into networks. It should be like a business traveler connecting to the Internet with a laptop in a random hotel room, without significant preplanning, Pino said.

This networking will greatly expand the use of video teleconferencing for US forces, a capability that is generally limited to commanders.

As is the case with the lasers, TSAT will represent the first operational use of the router technology aboard a military satellite. Like the lasers, there is precedent for incorporating IP routers in space—the technology is featured on the Boeing-built Spaceway 3 commercial communications satellite, which launched in August.

Despite the considerable work that has been completed in developing and testing the technology for the individual components of the TSAT satellites such as the laser and router, the rest of the effort will still be challenging, Payton said.

While the Air Force is confident that the individual components will work, still to come is “the tough part”—integrating those pieces into the satellite system, Payton said.

Congress has been intrigued by the promise of TSAT since the beginning, but has been skeptical about the cost and risk involved with the development of the laser-linked satellites.

Keep Them on Track

The Advanced EHF system is the Milstar successor and TSAT’s predecessor. When the Air Force began development on TSAT, the service truncated its planned AEHF acquisition. The buy was cut off at three satellites from five, with the first scheduled to launch in 2009.

Lawmakers have repeatedly pushed the Air Force to slow TSAT development to a more cautious pace, and buy at least one more AEHF satellite in the interim. They see this as insurance, to avoid a possible gap in communications coverage that could result if TSAT runs into the technical problems that have plagued the other satellites in the Air Force’s space acquisition portfolio.

The Air Force believes it has properly addressed risk and would prefer to keep those satellites on track. The alternative is to slow the work and take money from the TSAT program to buy another Advanced EHF, according to Lt. Gen. Michael A. Hamel, commander of Space and Missile Systems Center.

As head of Air Force Space Command, Gen. Kevin Chilton—left, shown here in 2007—was anxious to get TSAT fielded. (USAF photo)

Though the Congressional push for a fourth Advanced EHF satellite continues, the Air Force’s TSAT budget requests have been treated somewhat more gently on Capitol Hill over the past two years. Congressional staffers have in fact pointed to the program during conference speeches as a model for future space acquisition work.

Officials are hoping the huge increase in communications capability that comes from TSAT will play a significant role in reducing use of commercial satellite services, which today make up about 80 percent of the communications bandwidth used by US forces operating in Afghanistan and Iraq.

Some officials feel that that the Defense Department needs to reduce its dependence on commercial satellite services. Some capability is provided by firms based in the Middle East, where host governments may not always be friendly to the United States.

While commercial satellite services have proved valuable, they lack the ability to resist jamming and other types of interference. It would require “a heroic effort” for an adversary to even come close to jamming TSAT, Pino said.

Another security concern is that commercial systems are more vulnerable to the threat of an enemy hijacking the spacecraft for its own use. This has happened; Kwiatkowski pointed to the Liberation Tigers of Tamil Eelam’s hijacking of a transponder aboard a satellite operated by Intelsat. The Tamil Tigers then broadcast the group’s message in Sri Lanka.

Jeremy Singer is a Boston-based staff writer for Space News. He covers the Pentagon and is the editor for special projects. His most recent article for Air Force Magazine, “Bandwidth Breakthrough,” appeared in the March 2007 issue.

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