Enchanced space-based communication capability coming to the warfighter

  • Published
  • By Michael P. Kleiman
  • 377th Air Base Wing Public Affairs
KIRTLAND AFB, N.M. --  If U.S. Navy Lt. Michael P. Murphy had had the capability in June 2005 to communicate to a satellite from under the cover of rocks, requesting help while he and three fellow SEALs took enemy fire in the Hindu Kush Mountains of Afghanistan, the posthumous Medal of Honor recipient might still be alive today.

Due to the rugged terrain, Lt. Murphy positioned himself in open space to contact his headquarters via spacecraft, and in doing so, became vulnerable to the adversary's attack.

More than six years later, the Naval Research Laboratory-led Tactical Satellite-4, scheduled to launch Tuesday on a Minotaur IV rocket from the Alaska Aerospace Corp.'s Kodiak Launch Complex, Kodiak, Alaska, features a communications experiment comprised of 10 ultra-high frequency channels, which can be accessed by the deployed warfighter regardless of the landscape.

Following liftoff, TacSat-4, scheduled for a year-long mission, will undergo a two-week evaluation period as program members serving at the NRL's Satellite Operations Center, Blossom Point, Md., conduct checkouts of the COMMx payload and other support systems. Shortly thereafter, the spacecraft's lone trial will be exercised during its initial five months of flight. During that period, combatant commands and satellite communication personnel will also perform payload tasks using the classified, web-based Virtual Mission Operations Center.

If the COMMx transmits useful data up to the midway point of TacSat-4's mission, project personnel could then decide to transition the spacecraft from experimental demonstration to operational asset.
"I am really excited about TacSat-4. It is a little bit of a surprise, as not many people have paid attention to it. It is sort of an underdog mission," said Dr. Peter M. Wegner, director, Operationally Responsive Space Office at Kirtland Air Force Base. "Nevertheless, when the spacecraft gets into orbit, it is going to open some eyes as to what small satellites can do in providing big-time capabilities to the warfighter."

Wegner's organization is a significant supporter of the TacSat-4 project, as it has funded the launch, the spacecraft's Joint Military Utility Assessment, which will be conducted during the first 150 days of the experimental mission and the satellite's first six months of operational use.

Once placed in space, TacSat-4 will maintain a highly elliptical orbit of 435 miles by 7,470 miles at a 63.4-degree inclination. This unique flight path, three times closer to the Earth than most communications spacecraft, which operate directly above the equator in geostationary orbit with a period equal to the Earth's rotation, will enable TacSat-4 to provide four-hour coverage in the northern hemisphere during each of its six daily treks around the globe.

Because of TacSat-4's closer proximity to the planet, deployed military members will soon have the unique capability of using a hand-held radio and/or man-pack radio to contact the spacecraft using the 10 UHF channels. Likewise, various users and missions will have access to TacSat-4 through the VMOC.

"Being able to communicate on the move with a hand-held, legacy military radio is huge. This capability does not currently exist," Wegner said.

TacSat-4 is a collaborative effort, which includes participation from John Hopkins University's Applied Physics Laboratory, Air Force Research Laboratory, Air Force Space and Missile Systems Center, Orbital Sciences Corp., ATK Spacecraft Systems and Services, Ball Aerospace & Technologies Corp., The Boeing Company, Raytheon Company, General Dynamics, Massachusetts Institute of Technology Lincoln Laboratory, Sierra Nevada Corp., Design Net Engineering, AIS Corp., Microcosm, Inc., and Space Systems/Loral.

"With this capability, we want to make sure that troops with hand-held and/or man-pack radios will be able to talk to TacSat-4. With the spacecraft's payload comprised of 10 UHF channels, it will fill in areas where there is not much satellite communication coverage now," said Michael S. Hurley, TacSat-4 principal investigator, NRL. "In addition, the VMOC provides interface between the user and the satellite. As a mission-planning tool, it takes the user's input and requests to ops within 24 hours. TacSat-4 will significantly enhance the warfighter's communication capability, and in the process, save lives."