TacSat-3 is the second 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 ...
. It was assembled in an
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 ...
(AFRL) Space Vehicles Directorate facility at
Kirtland Air Force Base
Kirtland Air Force Base is a United States Air Force base located in the southeast quadrant of the Albuquerque, New Mexico urban area, adjacent to the Albuquerque International Sunport. The base was named for the early Army aviator Col. Roy ...
,
New Mexico
)
, population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano)
, seat = Santa Fe
, LargestCity = Albuquerque
, LargestMetro = Tiguex
, OfficialLang = None
, Languages = English, Spanish ( New Mexican), Navajo, Ker ...
. The TacSat satellites are all designed to demonstrate the ability to provide real-time data collected from space to combatant commanders in the field.
TacSat-3 includes three distinct payloads:
* the Advanced Responsive Tactically Effective Military Imaging Spectrometer (ARTEMIS) hyperspectral imager,
* the
Ocean Data Telemetry Microsatellite Link and
* the Space Avionics Experiment.
Design
TacSat-3 uses a standard satellite bus developed and provided by
ATK.
The payload consists of a two mirror
Ritchey–Chrétien telescope
A Ritchey–Chrétien telescope (RCT or simply RC) is a specialized variant of the Cassegrain telescope that has a hyperbolic primary mirror and a hyperbolic secondary mirror designed to eliminate off-axis optical errors (coma). The RCT has a wi ...
plus correction optics, with a
focus
Focus, or its plural form foci may refer to:
Arts
* Focus or Focus Festival, former name of the Adelaide Fringe arts festival in South Australia Film
*''Focus'', a 1962 TV film starring James Whitmore
* ''Focus'' (2001 film), a 2001 film based ...
device incorporated in the secondary mirror unit, and with a slit Offner spectrometer. The spectrometer uses the ARTEMIS hyperspectral imaging sensor (HSI), which is a single
HgCdTe Hg1−xCdxTe or mercury cadmium telluride (also cadmium mercury telluride, MCT, MerCad Telluride, MerCadTel, MerCaT or CMT) is a chemical compound of cadmium telluride (CdTe) and mercury telluride (HgTe) with a tunable bandgap spanning the shortwave ...
Focal Plane Array
A staring array, also known as staring-plane array or focal-plane array (FPA), is an image sensor consisting of an array (typically rectangular) of light-sensing pixels at the focal plane of a lens. FPAs are used most commonly for imaging purpo ...
covering the entire V/NIR/
SWIR spectrum from 400 nm to 2500 nm at a uniform resolution of 5 nm. ARTEMIS measures first the spectral information at each point on the ground in 400 spectral channels. HSI data cubes obtained by ARTEMIS are then handled by a reprogrammable digital signal processor with 16
gigabit
The bit is the most basic unit of information in computing and digital communications. The name is a portmanteau of binary digit. The bit represents a logical state with one of two possible values. These values are most commonly represented a ...
data storage capability to generate on-board products and for in-theater downlink.
[Alt URL]
/ref>[ ] TacSat-3's main focus is land-based HSI. According to Peter Wegner from 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 ...
, TacSat-3 cost US$90 million.
Launch
In January 2009, the Air Force announced that a malfunctioning component has postponed the launch date on its Minotaur
In Greek mythology, the Minotaur ( , ;. grc, ; in Latin as ''Minotaurus'' ) is a mythical creature portrayed during classical antiquity with the head and tail of a bull and the body of a man or, as described by Roman poet Ovid, a being "pa ...
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 ...
. However, in March 2009 it was announced that the component issues had been resolved and a launch date was set for 5 May 2009. The 5 May 2009 launch attempt was scrubbed and a new launch date was set for 19 May 2009, with a backup date of 20 May 2009. The launch occurred successfully at 23:55 UTC on 19 May 2009, 20 minutes into a launch window running from 23:35 to 03:30 UTC each night.
The first attempt to launch TacSat-3 was made on 6 May 2009, during a window running from 00:00-03:00 UTC. However, due to thunderstorms and very low ceilings which prevented the surveillance plane from taking off, this launch attempt was scrubbed and the next attempt was scheduled for 8 May 2009 during the same window. The 8 May 2009 attempt was also scrubbed due to thunderstorms and heavy rain, which once again, prevented the surveillance plane from being able to take off. Another attempt was scheduled for the next day on 9 May 2009, again with the same window. Although the weather cooperated better for the 9 May 2009 attempt, a launch support equipment problem caused a delay of approximately three hours past the scheduled launch time. This problem was resolved and the countdown resumed. However, with 2 minutes and 16 seconds left on the countdown clock, an unexpected hold was called. Several minutes later, this launch attempt was also scrubbed due to low electrical voltage on the AGC of the Flight Termination System. A new launch date was set for 19 May 2009 with 20 May 2009 as a backup date.
The spacecraft was successfully launched at 23:55 UTC on 19 May 2009 after a small delay to remove off shore boaters from the exclusion area.
Mission
TacSat-3 achieved a HSI ground resolution of 4 meters, which enabled it to detect and identify tactical targets. After a successful completion of a one-year experimental phase, and the acquisition of more than 2100 images, TacSat-3 was handed over to the Air Force in June 2010 as a full-time operational asset. It is the first hyperspectral satellite with the ability to provide reconnaissance within 10 minutes after passing overhead. Field commanders using tactical radio equipment, such as the AN/PRC-117F Multiband Manpack Radio, can directly communicate with the satellite in the 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) band.[ ] TacSat-3/ARTEMIS observations of the National Mall
The National Mall is a Landscape architecture, landscaped park near the Downtown, Washington, D.C., downtown area of Washington, D.C., the capital city of the United States. It contains and borders a number of museums of the Smithsonian Institut ...
and the Kilauea Volcano to support technical validation of the sensor have been released in June 2010. The released images comprise three of the more than 400 spectral bands.[ ]
TacSat-3 completed operations on 15 February 2012. On 30 April 2012, following the decay
Decay may refer to:
Science and technology
* Bit decay, in computing
* Software decay, in computing
* Distance decay, in geography
* Decay time (fall time), in electronics
Biology
* Decomposition of organic matter
* Tooth decay (dental caries) ...
of its orbit, TacSat-3 reentered the Earth's atmosphere and burned up.[ ]
Gallery
File:TacSat3Bus.png, TacSat-3 bus during integration
File:TacSat3 testing.jpg, TacSat-3 at final integration and testing
File:14inch RCOpticalSystems2.jpg, 35 cm Ritchey-Chrétien telescope
File:Tacsat3 theater reconnaissance.png, Tactical theater reconnaissance
References
External links
TacSat-3 Information
- includes information about ARTEMIS
Survey and Analysis of Fore-Optics for Hyperspectral Imaging Systems
RC Optical Systems 16" f/8.4 Ritchey-Chrétien Carbon Fiber Optical Tube
summary of design specifics and close-up of Ritchey-Chrétien Secondary Focuser
{{Orbital launches in 2009
Spacecraft launched in 2009
Spacecraft launched by Minotaur rockets
Spacecraft which reentered in 2012