Space Test Program


The Space Test Program (STP) is the primary provider of spaceflight for the United States Department of Defense (DoD) space science and technology community. STP is managed by a group within the Advanced Systems and Development Directorate, a directorate of the Space and Missile Systems Center of the United States Space Force. STP provides spaceflight via the International Space Station (ISS), piggybacks, secondary payloads and dedicated launch services.

Past activitiesEdit

STP has actually been in existence for 50 years as of 2019, with several thousand launches it has been responsible for. For example, the initial experiments that led to the modern Global Positioning System (GPS) satellite constellation were STP-launched projects.


During August 2001, STP conducted two successful activities using the Space Shuttle and ISS. STS-105 delivered and successfully deployed the Materials International Space Station Experiment (MISSE) externally on the ISS. MISSE was a passive materials exposure experiment, was the first external experiment on ISS. In addition, STS-105 retrieved and returned MACE II (Middeck Active Control Experiment II) from the ISS. MACE II was the first internal experiment on ISS and was operated for nearly a year.[1]

On 30 September 2001, STP and NASA launched the Kodiak Star mission on an Athena I launch vehicle. This was the first orbital launch out of Kodiak Island, Alaska. In addition to NASA's Starshine III spacecraft, this mission included three small DoD spacecraft which tested a variety of new space technologies.[2]

STP and the Air Force Research Laboratory's (AFRL) Space Vehicles Directorate developed a secondary payload adapter ring for the Evolved Expendable Launch Vehicle (EELV), which can host up to six 180 kg (400 lb) microsatellites. STP also worked closely with NASA and the United States Navy on the Geosynchronous Imaging Fourier Transform Spectrometer / Indian Ocean Meteorology and Oceanography Imager project.[citation needed]

In December 2001, STS-108 hosted the Shuttle Ionospheric Modification with Pulsed Localized Exhaust (SIMPLEX) experiment. SIMPLEX observed ionospheric disturbances created by the Space Shuttle engine burns via ground radar sites and supported plume technology, plume signature, and space weather modeling.[citation needed]


SIMPLEX flew again on STS-110 in April 2002.[citation needed] STP also worked to obtain a 1-year radio frequency license extension for the Picosat experiment launched on the Kodiak Star mission, in September 2001.[citation needed]


On 6 January 2003, STP and the Naval Research Laboratory (NRL) launched the Coriolis satellite, a risk-reduction effort for NPOESS, aboard a Titan II launch vehicle.[3]


On 9 March 2007, six satellites were launched into low Earth Orbit (LEO) on a shared Atlas V launch vehicle on the STP-1 mission.[4] The satellites were:

The satellites shared the launcher through use of an Evolved Expendable Launch Vehicle Secondary Payload Adapter (ESPA).[5] United Launch Alliance provided a video feed of the launch.[6]


The C/NOFS (Communications/Navigation Outage Forecasting System) satellite, which was launched on 16 April 2008, was operated by the Space Test Program.


The third Minotaur IV, known as STP-S26, was successfully launched in November 2010. This was the 26th small launch vehicle mission in STP's 40-year history of flying DoD space experiments,[7] STP-S26 launched at 01:45 UTC on 20 November 2010 from the Kodiak Launch Complex. The launch facility contractor was Alaska Aerospace Corporation (AAC). The payloads were released in a 650 km (400 mi) orbit, before the Hydrazine Auxiliary Propulsion System (HAPS) upper stage, by Orbital Sciences Corporation, was demonstrated by deploying two ballast payloads into a 1,200 km (750 mi) orbit. The payload included the STPSat-2 spacecraft.[8] STPSat-2 had 3 three experimental payloads: SPEX (Space Phenomenology Experiment) consisting of two payloads to evaluate sensor compatibility for the space environment, and ODTML (Ocean Data Telemetry MicroSatLink) a two-way data relay from terrestrial (ocean or land) sensors to users.[9]


STPSat 3 is a copy[clarification needed] of the STPSat-2 satellite, adapted to carry six experiments, including a module designed to host various space situational awareness sensors and a pair of space environment sensors. STPSat 3 launched on 19 November 2013, on the ORS-3 Minotaur 1 launch, along with 28 CubeSats.[10] STPSat-3 carries five payloads, including "Integrated Miniaturized Electrostatic Analyzer Reflight (iMESA-R), Joint Component Research (J-CORE), Strip Sensor Unit (SSU), Small Wind and Temperature Spectrometer (SWATS), and TSI Calibration Transfer Experiment (TCTE)". It also carries a de-orbit module.[8]


As announced on 14 October 2014, the United States Department of Defense awarded Sierra Nevada Corporation's Space Systems (previously known as SpaceDev) with a contract to develop and build a next-generation science and technology demonstration satellite, known as STPSat-5, for their Space Test Program.[11][unreliable source?]


The STP-2 (DoD Space Test Program) payload launched aboard a SpaceX Falcon Heavy on 25 June 2019.[12][clarification needed]

Included was COSMIC-2, a cluster of six satellites, with a mass of 277.8 kg (612 lb) each.[13] The primary role of the COSMIC-2 satellite constellation is to provide radio occultation data with an average latency of 45 minutes. The six satellites were placed on an orbit with an inclination of 24° to 28.5°[which?] with plans for them to move eventually to six separate orbital planes with 60° separation between them.[14] The payload stack was integrated using an ESPA ring. Two ESPA Grande rings were used to mount the six COSMIC-2 satellites beneath the upper payload adapter hosting the DSX payload and avionics modules.[15]

STP-2 also deployed a number of CubeSats as secondary payloads,[13] including E-TBEx, PSAT, TEPCE, and ELaNa 15 CubeSats.[16] LightSail 2[17] is carried by the Prox-1 nanosatellite.[17] Other satellites and payloads included Oculus-ASR nanosatellite,[18] GPIM,[19][20][21] and the Deep Space Atomic Clock.[22]


The STP-3 mission was originally scheduled to be launched on a ULA Atlas V 551 launch vehicle in 2020.[23][24] It was launched on 7 December 2021 at 10:19 UTC.[25] It includes the STPSat-6 satellite with the Space and Atmospheric Burst Reporting System-3 (SABRS-3) for National Nuclear Security Administration (NNSA), Laser Communications Relay Demonstration (LCRD) payload for NASA, and seven secondary payloads for the U.S. Air Force. STPSat-6 is destined for an orbit slightly above the geostationary orbit.[24] SpaceX bid a Falcon Heavy in December 2016 for this launch.[23]


  1. ^ "2001 Aeronautics and Space Report of the President". NASA.   This article incorporates text from this source, which is in the public domain.
  2. ^ NASA: Kodiak Star 2001 Archived 2012-03-24 at the Wayback Machine   This article incorporates text from this source, which is in the public domain.
  3. ^ "WINDSAT Project Description". NOAA. Archived from the original on 9 November 2005.   This article incorporates text from this source, which is in the public domain.
  4. ^ "Space Test Program (STP) Payloads". Gunter's Space Page. 2 November 2021. Retrieved 19 November 2021.
  5. ^ "Atlas V Multiple and Secondary Payload Carriers" (PDF). Lockheed Martin.[permanent dead link]
  6. ^ "Atlas V launch". YouTube.
  7. ^ Brinton, Turner. "Air Force's STP-S26 Mission Loaded with New Technologies". SpaceNews. Retrieved 8 December 2016.
  8. ^ a b "STPSat-2 Experimental Satellite". Retrieved 19 December 2017.
  9. ^ STPSat-2
  10. ^ ORS-3 and Minotaur 1 launch tiny CubeSats full of big promise
  11. ^ "US DoD awards STPSat-5 satellite production contract to Sierra Nevada". airforce-technology,com. 16 October 2014. Retrieved 16 October 2014.
  12. ^ "SpaceX ready for most-challenging flight with Falcon Heavy's STP-2 mission". 24 June 2019. Retrieved 25 June 2019.
  13. ^ a b "Mission Requirements Document (MRD) FA8818-12-R-0026 T.O. SM-2.4".
  14. ^ "NARLabs-FORMOSAT-7-COSMIC-2-Mission". NARLabs.
  15. ^ "DSX (Cygnus)". Gunter's Space Page.
  16. ^ STP-2
  17. ^ a b "Lightsail". Planetary Society. Retrieved 21 April 2015.
  18. ^ "Oculus-ASR". Gunter's Space Page. Retrieved 15 March 2016.
  19. ^ "About Green Propellant Infusion Mission (GPIM)". NASA. 2014. Retrieved 26 February 2014.   This article incorporates text from this source, which is in the public domain.
  20. ^ "Green Propellant Infusion Mission (GPIM)". Ball Aerospace. 2014. Retrieved 26 February 2014.
  21. ^ "The Green Propellant Infusion Mission (GPIM)" (PDF). Ball Aerospace & Technologies Corp. March 2013. Archived from the original (PDF) on 20 December 2015. Retrieved 26 February 2014.
  22. ^ "Deep Space Atomic Clock". Jet Propulsion Laboratory. NASA. 27 April 2015. Retrieved 28 October 2015.   This article incorporates text from this source, which is in the public domain.
  23. ^ a b Swarts, Phillip (29 June 2017). "ULA wins competition for US$191 million Air Force launch". SpaceNews. Retrieved 1 February 2018.
  24. ^ a b Krebs, Gunter (5 December 2021). "STPSat 6". Gunter's Space Page. Retrieved 7 December 2021.
  25. ^ "Fuel leak at launch pad delays Atlas 5 mission". Spaceflight Now. 5 December 2021. Retrieved 6 December 2021.

External linksEdit

  • List of all Space Test Program Missions