TacSat-2 is the first in a series of U.S. military experimental technology and communication satellites.TacSat-2 (also known as JWS-D1 ((Joint Warfighting Space-Demonstrator 1) or RoadRunner)[2] was an experimental satellite built by the USAF's Air Force Research Laboratory with an operational life expected to be not more than one year as part of the "Advanced Concept Technology Demonstration" program.

TacSat-2 illustration.jpg
Artist's rendering of TacSat-2 imaging satellite
Mission typeTechnology, Communications
OperatorAir Force Research Laboratory
COSPAR ID2006-058A Edit this at Wikidata
SATCAT no.29653
Mission duration1 year (planned)
4 years (achieved)
Spacecraft properties
SpacecraftTacSat 2
BusRoad Runner Bus (NGMB, Next Generation Multifunctional Bus)
ManufacturerMicroSat Systems Inc. (MSI) (bus)
Launch mass370 kg (820 lb)
Power500 watts
Start of mission
Launch date16 December 2006, 12:00:00 UTC
RocketMinotaur I # 6
Launch siteMARS, Wallops Island, LP-0B
ContractorOrbital Sciences Corporation
End of mission
Decay date5 February 2011
Orbital parameters
Reference systemGeocentric orbit[1]
RegimeLow Earth orbit
Perigee altitude413 km (257 mi)
Apogee altitude424 km (263 mi)
Period92.90 minutes


The TacSat series of experimental spacecraft are designed to allow military commanders on a battlefield to request and obtain imagery and other data from a satellite as it passes overhead. Collected data will be delivered to field commanders in minutes rather than hours or days. The sensor on TacSat-2 could collect color images sharp enough to distinguish ground objects as small as 1 meter in diameter.[3]


Satellites in the TacSat series were planned to use commercial or available launchers, and largely off-the-shelf components, in order to reduce costs.

Satellite busEdit

The satellite bus was built by MicroSat Systems Inc. (MSI) of Littleton, Colorado. The core avionics of the spacecraft including command and data handling, electrical power switching and distribution, and subsystem and payload interfaces was handled by an Integrated Avionics Unit (IAU) developed by Broad Reach Engineering. The spacecraft flight software consisted of the low level drivers, and bus manager functionality provided by Broad Reach Engineering, ADCS Software by ASI, and a number of higher level applications by third parties, most notably the Autonomous Tasking Experiment (ATE) by Interface & Control Systems.

Camera / telescopeEdit

TacSat-2 during integration
Launch of TacSat-2

The developers originally asked for bids from contractors for a camera. These were priced at around US$10 million. The team then bought a high-end observatory telescope costing around US$20,000 and added a camera sensor (US$2 million), delivering a sensor capable of 1m ground resolution.[4]

The telescope had 50 cm aperture and was from RC Optical Systems.[5]

Signals intelligenceEdit

A signals intelligence payload, called the Target Indicator Experiment, detected radio wave emitters and could be used in concert with receivers on other platforms such as the US Navy's P-3C maritime patrol aircraft.

Other systems included:

  • RoadRunner Onboard Processing Experiment (ROPE)
  • Common Data Link (CDL)
  • Autonomous Operations
  • Hall Effect Thruster (HET)
  • Propulsion Instrument Electronics (PIE) sensor suite
  • Inertial Stellar Compass (ISC)
  • Low Power Transceiver (LPT)
  • Integrated GPS Occultation Receiver (IGOR) [6]
  • Atmospheric Density Mass Spectrometer (ADMS)
  • Experimental solar array
  • Miniaturized Vibration Isolation System (MVIS)


Apart from the Air Force Research Laboratory (AFRL), other organisations participating included:


TacSat-2 was launched on 16 December 2006 from the Mid-Atlantic Regional Spaceport, Wallops Island Flight Facility, using an Orbital Sciences Corporation (OSC) Minotaur I launch vehicle. The Mid-Atlantic Regional Spaceport is a commercial space launch facility located on the Delmarva Peninsula 8 km (5.0 mi) west of Chincoteague, Virginia.


The near circular orbit had a height of 410 km at an inclination of 40.0° to the equator. TacSat-2 decayed on 5 February 2011.

See alsoEdit


  1. ^ "Trajectory: TacSat 2 2006-058A". NASA. 13 April 2021. Retrieved 19 April 2021.   This article incorporates text from this source, which is in the public domain.
  2. ^ "Key Elements of Rapid Integration and Test" (PDF). Archived from the original (PDF) on 30 September 2007. Retrieved 28 June 2007.
  3. ^ Singer, Jeremy (4 December 2006). "USAF To Experiment With Satellite To Improve Ground Communications". Defense News. Archived from the original on 24 July 2012.
  4. ^ Singer, Jeremy (7 December 2006). "TacSat-2 Ushers in New Era in Satellite Operations". SpaceNews. Retrieved 25 November 2022.
  5. ^ "Alphabetic Index". Encyclopedia Astronautica. 2016. Archived from the original on 10 July 2016. Retrieved 19 April 2021.
  6. ^ "Integrated GPS Occultation Receiver". Broad Reach Engineering. Archived from the original on 1 December 2008. Retrieved 2 April 2007.

External linksEdit

  • USAF (1 September 2006), TacSat-2 Micro Satellite (PDF), Air Force Research Laboratory, archived from the original (PDF) on 12 July 2007, retrieved 18 December 2006
  • "TacSat-2 Mission Information". NASA.