TacSat-4 is the fourth in a series of U.S. military experimental reconnaissance and communication satellites. The Naval Research Laboratory (NRL) is the program manager. The Office of Naval Research

Office of Naval Research

The Office of Naval Research , headquartered in Arlington, Virginia , is the office within the United States Department of the Navy that coordinates, executes, and promotes the science and technology programs of the U.S...

 (ONR) sponsored the development of the payload and funded the first year of operations. The Office of the Director of Defense Research and Engineering

Director of Defense Research and Engineering

The Assistant Secretary of Defense for Research and Engineering ASD is a senior official of the United States Department of Defense. The ASD and the office s/he heads are charged with the development and oversight of DoD technology strategy for the DoD. The ASD reports to the Under Secretary of...

 (DDR&E) funded the standardized spacecraft bus and the Operationally Responsive Space Office

Operationally Responsive Space Office

The Operationally Responsive Space Office is a joint initiative of several agencies within the United States Department of Defense . The "stand up" of the office took place 2007-05-21 at Kirtland Air Force Base. The first director of the ORS Office is Col. Kevin McLaughlin, who is also commander...

 (ORS) funded the launch that will be performed by the Air Force’s Space and Missile Systems Center

Space and Missile Systems Center

The Space and Missile Systems Center is a part of Air Force Space Command of the United States Air Force. SMC is the Air Force’s product center for the development and acquisition of space and missile systems...

 (SMC).

The spacecraft was completed by the end of 2009, and was launched on September 27, 2011, on a Minotaur IV

Minotaur IV

Minotaur IV, also known as Peacekeeper SLV and OSP-2 PK is an active expendable launch system derived from the Peacekeeper missile. It is operated by Orbital Sciences Corporation, and made its maiden flight on 22 April 2010, carrying the HTV-2a Hypersonic Test Vehicle...

 rocket into a highly elliptical orbit

Highly Elliptical Orbit

A highly elliptical orbit is an elliptic orbit with a low-altitude perigee and a high-altitude apogee. It is a type of high Earth orbit....

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Mission

TacSat-4 is equipped with a 3.8 m (12.5 ft) antenna operating 10 Ultra High Frequency

Ultra high frequency

Ultra-High Frequency designates the ITU Radio frequency range of electromagnetic waves between 300 MHz and 3 GHz , also known as the decimetre band or decimetre wave as the wavelengths range from one to ten decimetres...

 (UHF) channels that can be used for any combination of communications, data ex-filtration or Blue Force Tracking

Blue Force Tracking

Blue Force Tracking is a United States military term used to denote a GPS-enabled system that provides military commanders and forces with location information about friendly military forces....

 (BFT). TacSat-4 will fly the highly elliptical, 4-hour, orbit (12,050 kilometers at peak) providing typical payload communication periods of two hours per orbit. TacSat-4’s orbit also allows it to cover the high latitudes.

Part of its capability is rapid (within 24 hours) reallocation to different theaters

Theater (warfare)

In warfare, a theater, is defined as an area or place within which important military events occur or are progressing. The entirety of the air, land, and sea area that is or that may potentially become involved in war operations....

 worldwide, in support of unexpected operations. Command and control of TacSat-4 will be performed at the NRL Satellite Operations Center at Blossom Point, Maryland. Payload tasking will be performed via the SIPRNet

SIPRNet

The Secret Internet Protocol Router Network is "a system of interconnected computer networks used by the United States Department of Defense and the U.S. Department of State to transmit classified information by packet switching over the TCP/IP protocols in a 'completely secure' environment"...

 based Virtual Mission Operations Center (VMOC).

Design

All TacSat satellites are designed to demonstrate the ability to provide real-time data collected from space to combatant commanders in the field.

The spacecraft bus was built by NRL and Johns Hopkins University Applied Physics Laboratory

Applied Physics Laboratory

The Johns Hopkins University Applied Physics Laboratory , located in Howard County, Maryland near Laurel and Columbia, is a not-for-profit, university-affiliated research center employing 4,500 people. APL is primarily a defense contractor. It serves as a technical resource for the Department of...

 (APL) to mature ORS bus standards developed by an Integrated (government and industry) System Engineering Team, the “ISET Team,” with active representation from AeroAstro, Air Force Research Laboratory

Air Force Research Laboratory

The Air Force Research Laboratory is a scientific research organization operated by the United States Air Force Materiel Command dedicated to leading the discovery, development, and integration of affordable aerospace warfighting technologies; planning and executing the Air Force science and...

, Johns Hopkins Laboratory APL, ATK Space, Ball Aerospace & Technologies, Boeing

Boeing

The Boeing Company is an American multinational aerospace and defense corporation, founded in 1916 by William E. Boeing in Seattle, Washington. Boeing has expanded over the years, merging with McDonnell Douglas in 1997. Boeing Corporate headquarters has been in Chicago, Illinois since 2001...

, Design Net Engineering, General Dynamics

General Dynamics

General Dynamics Corporation is a U.S. defense conglomerate formed by mergers and divestitures, and as of 2008 it is the fifth largest defense contractor in the world. Its headquarters are in West Falls Church , unincorporated Fairfax County, Virginia, in the Falls Church area.The company has...

 AIS, Microcosm, Sierra Nevada Corp., Massachusetts Institute of Technology

Massachusetts Institute of Technology

The Massachusetts Institute of Technology is a private research university located in Cambridge, Massachusetts. MIT has five schools and one college, containing a total of 32 academic departments, with a strong emphasis on scientific and technological education and research.Founded in 1861 in...

, Lincoln Laboratory

Lincoln Laboratory

MIT Lincoln Laboratory, located in Lexington, Massachusetts, is a United States Department of Defense research and development center chartered to apply advanced technology to problems of national security. Research and development activities focus on long-term technology development as well as...

, Orbital Sciences, NRL, SMC, Space Systems/Loral

Space Systems/Loral

Space Systems/Loral , of Palo Alto, California, is the wholly owned manufacturing subsidiary of Loral Space & Communications. It was acquired in 1990 for $715 million by Loral Corp. from Ford Motor Company as the Space Systems Division of Ford Aerospace...

, and Raytheon

Raytheon

Raytheon Company is a major American defense contractor and industrial corporation with core manufacturing concentrations in weapons and military and commercial electronics. It was previously involved in corporate and special-mission aircraft until early 2007...

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