TacSat-4 is the third in a series of U.S. military experimental

technology Technology is the application of knowledge to reach practical goals in a specifiable and reproducible way. The word ''technology'' may also mean the product of such an endeavor. The use of technology is widely prevalent in medicine, science, ...

and

communication satellites A communications satellite is an artificial satellite that relays and amplifies radio telecommunication signals via a transponder; it creates a communication channel between a source transmitter and a receiver at different locations on Earth. C ...

. The

United States Naval Research Laboratory The United States Naval Research Laboratory (NRL) is the corporate research laboratory for the United States Navy and the United States Marine Corps. It was founded in 1923 and conducts basic scientific research, applied research, technological ...

(NRL) is the program manager. The

Office of Naval Research The Office of Naval Research (ONR) is an organization within the United States Department of the Navy responsible for the science and technology programs of the U.S. Navy and Marine Corps. Established by Congress in 1946, its mission is to plan ...

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

Director of Defense Research and Engineering The Under Secretary of Defense for Research and Engineering, abbreviated USD (R&E), is a senior official of the United States Department of Defense. The USD (R&E) is charged with the development and oversight of technology strategy for the DoD. T ...

(DDR&E) funded the standardized spacecraft bus and the

Operationally Responsive Space Office The Operationally Responsive Space Office (ORS Office) is a joint initiative of several agencies within the United States Department of Defense (DoD). The "stand up" of the office took place 21 May 2007 at Kirtland Air Force Base. The first directo ...

(ORS) funded the launch that will be performed by the Air Force's

Space and Missile Systems Center Space Systems Command (SSC) is the United States Space Force's space development, acquisition, launch, and logistics field command. It is headquartered at Los Angeles Air Force Base, California and manages the United States' space launch ...

(SMC). The spacecraft was completed by the end of 2009, and was launched on 27 September 2011, at 14:49:00 UTC, on a

Minotaur IV Minotaur IV, also known as Peacekeeper SLV and OSP-2 PK is an active expendable launch system derived from the LGM-118 Peacekeeper ICBM. It is operated by Northrop Grumman Innovation Systems, and made its maiden flight on 22 April 2010, carrying ...

launch vehicle A launch vehicle or carrier rocket is a rocket designed to carry a payload (spacecraft or satellites) from the Earth's surface to outer space. Most launch vehicles operate from a launch pad, launch pads, supported by a missile launch contro ...

into a

highly elliptical orbit A highly elliptical orbit (HEO) is an elliptic orbit with high eccentricity, usually referring to one around Earth. Examples of inclined HEO orbits include Molniya orbits, named after the Molniya Soviet communication satellites which used them, ...

(HEO).

Mission

TacSat-4 is equipped with a antenna operating 10

Ultra High Frequency Ultra high frequency (UHF) is the ITU designation for radio frequency, radio frequencies in the range between 300 megahertz (MHz) and 3 gigahertz (GHz), also known as the decimetre band as the wavelengths range from one meter to one ten ...

(UHF) channels that can be used for any combination of communications, data ex-filtration or Blue Force Tracking (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 The polar regions, also called the frigid zones or polar zones, of Earth are the regions of the planet that surround its geographical poles (the North and South Poles), lying within the polar circles. These high latitudes are dominated by floa ...

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

theaters Theatre or theater is a collaborative form of performing art that uses live performers, usually actors or actresses, to present the experience of a real or imagined event before a live audience in a specific place, often a stage. The perform ...

worldwide, in support of unexpected operations. Command and control of TacSat-4 will be performed at the

(NRL) Satellite Operations Center at

Blossom Point Blossom Point (russian: Мыс Блоссом), also known as "Cape Blossom", is a headland of Wrangel Island. Administratively it belongs to the Chukotka Autonomous Okrug, Russian Federation. There are walruses and polar bears in the area of ...

Maryland Maryland ( ) is a state in the Mid-Atlantic region of the United States. It shares borders with Virginia, West Virginia, and the District of Columbia to its south and west; Pennsylvania to its north; and Delaware and the Atlantic Ocean to ...

. Payload tasking will be performed via the

SIPRNet The Secure Internet Protocol Router Network (SIPRNet) is "a system of interconnected computer networks used by the U.S. Department of Defense and the U.S. Department of State to transmit classified information (up to and including information cla ...

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 The Johns Hopkins University Applied Physics Laboratory (Applied Physics Laboratory, or APL) is a not-for-profit University Affiliated Research Center, university-affiliated research center (UARC) in Howard County, Maryland. It is affiliated w ...

(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 The Air Force Research Laboratory (AFRL) is a scientific research organization operated by the United States Air Force Materiel Command dedicated to leading the discovery, development, and integration of aerospace warfighting technologies, pl ...

Johns Hopkins University Applied Physics Laboratory The Johns Hopkins University Applied Physics Laboratory (Applied Physics Laboratory, or APL) is a not-for-profit university-affiliated research center (UARC) in Howard County, Maryland. It is affiliated with Johns Hopkins University and emplo ...

, ATK Space,

Ball Aerospace & Technologies Ball Aerospace & Technologies Corp. is an American manufacturer of spacecraft, components and instruments for national defense, civil space and commercial space applications. The company is a wholly owned subsidiary of Ball Corporation (NYSE: BAL ...

Boeing The Boeing Company () is an American multinational corporation that designs, manufactures, and sells airplanes, rotorcraft, rockets, satellites, telecommunications equipment, and missiles worldwide. The company also provides leasing and product ...

, Design Net Engineering,

General Dynamics General Dynamics Corporation (GD) is an American publicly traded, aerospace and defense corporation headquartered in Reston, Virginia. As of 2020, it was the fifth-largest defense contractor in the world by arms sales, and 5th largest in the Uni ...

AIS, Microcosm,

Sierra Nevada Corp. Sierra Nevada Corporation (SNC) is an American, privately held aerospace and national security contractor specializing in aircraft modification and integration, space components and systems, and related technology products for cybersecurity and ...

Massachusetts Institute of Technology The Massachusetts Institute of Technology (MIT) is a private land-grant research university in Cambridge, Massachusetts. Established in 1861, MIT has played a key role in the development of modern technology and science, and is one of the ...

Lincoln Laboratory The MIT Lincoln Laboratory, located in Lexington, Massachusetts, is a United States Department of Defense federally funded research and development center chartered to apply advanced technology to problems of national security. Research and dev ...

Orbital Sciences Corporation Orbital Sciences Corporation (commonly referred to as Orbital) was an American company specializing in the design, manufacture, and launch of small- and medium- class space and launch vehicle systems for commercial, military and other governmen ...

, NRL, SMC,

Space Systems/Loral SSL, formerly Space Systems/Loral, LLC (SS/L), of Palo Alto, California, is a wholly owned manufacturing subsidiary of Maxar Technologies. SSL designs and builds satellites and space systems for a wide variety of government and commercial cust ...

, and

Raytheon Raytheon Technologies Corporation is an American multinational aerospace and defense conglomerate headquartered in Arlington, Virginia. It is one of the largest aerospace and defense manufacturers in the world by revenue and market capitaliza ...

Lithium-ion battery A lithium-ion or Li-ion battery is a type of rechargeable battery which uses the reversible reduction of lithium ions to store energy. It is the predominant battery type used in portable consumer electronics and electric vehicles. It also se ...

power provided by Quallion.

Gallery

References

External links

TacSat-4 (Tactical Satellite-4)
eoPortal, on the eo "Sharing Earth Observation Resources" website {{AFRL spacecraft Spacecraft launched in 2011