The Navy's Tactical Satellite-IV (TacSat-4) successfully launched Sept. 27 aboard an Orbital Sciences Minotaur-IV+ launch vehicle from the Alaska Aerospace Corporation's (AAC) Kodiak Launch Complex, Kodiak Island, Alaska.

The spacecraft augments current geosynchronous satellite communications, having an apogee of 12,050 kilometers in the high latitudes to deliver near, although not continuous, global communications on-the-move (COTM) to the battlefield and provide access to mountainous regions that have previously proved problematic.

TacSat-4 is a Navy-led joint mission that provides 10 Ultra High Frequency (UHF) channels and allows forward deployed troops to communicate from obscured regions using existing hand-held radios without the need to stop and point an antenna towards the satellite.

"TacSat-4 supports a critical warfighting requirement: communication," said Chief of Naval Research Rear Adm. Nevin Carr. "We've developed a technology that will supplement traditional satellites, giving military personnel on the ground another outlet for data transmission and facilitating 'comms on the move,'"

TacSat-4 provides flexible up and down channel assignments, which increase the ability to operate in busy radio-frequency environments and will cover the high latitudes and mountainous areas where users currently cannot access UHF satellite communications (SATCOMs).

The NRL Blossom Point Ground Station provides the command and control for TacSat-4 and maintains its user Virtual Mission Operations Center (VMOC) tasking system, allowing dynamic reallocation to different theaters worldwide and enabling rapid SATCOM augmentation when unexpected operations or natural events occur.

TacSat-4 is an experimental spacecraft that will test advances in several technologies and SATCOM techniques. It will augment the existing fleet by giving the SATCOM Support Centers (SSC) an additional space asset to provide communications to otherwise under-served users and areas that either do not have high enough priority or do not have satellite visibility.

The project will potentially provide the option for launching smaller highly elliptical orbit (HEO) satellites and enabling 24-hour coverage in multiple regions simultaneously, allowing the military to achieve the benefits of a combined HEO and geosynchronous orbit constellation.

The spacecraft bus was built by NRL and Johns Hopkins University Applied Physics Laboratory (APL) to mature ORS bus standards.

It was developed by an Integrated (government and industry) System Engineering Team, the "ISET Team," with active representation from AeroAstro, Air Force Research Laboratory, Johns Hopkins Laboratory APL, ATK Space, Ball Aerospace and Technologies, Boeing, Design Net Engineering, General Dynamics AIS, Microcosm, Microsat Systems Inc., Massachusetts Institute of Technology Lincoln Laboratory, Orbital Sciences, NRL, SMC, Space System Loral, and Raytheon.

earlier related report
Orbital Successfully Launches Minotaur IV Rocket for U.S. Air Force Carrying TacSat-4 Satellite
Dulles, VA (SPX) Sep 30 - Orbital Sciences reports that its Minotaur IV space launch vehicle was successfully launched for the U.S. Air Force, placing the U.S. Navy's Tactical Satellite-4 (TacSat-4) into a precise orbit of the Earth.

The Operationally Responsive Space (ORS) Office is the launch sponsor of the TacSat-4 program, which is demonstrating the use of standard interfaces to shorten development timelines and delivering tactical capabilities to the foot soldier.

The mission originated from the Kodiak Launch Complex in Alaska on September 27, 2011. The rocket's first stage ignited at 11:49 a.m. (EDT), beginning its flight into low-Earth orbit.

Approximately 28 minutes later, the Minotaur IV deployed the TacSat-4 satellite into its targeted highly elliptical orbit of approximately 7,415 miles (11,865 kilometers) by 115 miles (185 kilometers) above the Earth's surface.

The TacSat-4 launch was the fifth Minotaur IV flight and the 23rd overall mission for the Minotaur product line over the last 11 years, all of which have been successful.

"The successful Minotaur IV flight continues our well-established record of mission success for the Minotaur rocket family. Orbital is proud to support the U.S. Air Force with the newest member of the Minotaur launch vehicle family for the operationally responsive TacSat program," said Mr. Ron Grabe, Orbital's Executive Vice President and General Manager of its Launch Systems Group.

"With a perfect track record of 23 successful launches over the last 11 years, the Minotaur family has proven to be a valuable asset for the Department of Defense to meet its space launch needs."

The Minotaur family of launch vehicles is based on government-furnished Peacekeeper and Minuteman rocket motors that Orbital has upgraded and integrated with modern avionics and other subsystems to produce a cost-effective launcher based on flight-proven hardware.

The Minotaur product line utilizes standardized avionics and subsystems, mature processes and experienced personnel to make them reliable and cost effective. Minotaur rockets are capable of launching from all major U.S. spaceports, including launch sites in Alaska, California, Florida and Virginia.