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. But STP is a DoD-wide organization. STP provides spaceflight via the International Space Station, piggybacks, secondary payloads and dedicated launch services.
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 GPS satellite constellation were STP-launched projects.
During August 2001 STP conducted two successful activities using the Shuttle and ISS. STS-105 delivered and successfully deployed the Materials International Space Station Experiment (Materials International Space Station Experiment (MISSE)) externally on the ISS. MISSE, a passive materials exposure experiment, is 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 experiment on ISS and was operated for nearly a year.
On September 30, 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.
STP and the Air Force Research Laboratory’s Space Vehicles Directorate developed a secondary payload adapter ring for the Evolved Expendable Launch Vehicle (EELV), which can host up to six 400-pound micro satellites. 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.
In December 2001, STS-108 hosted the Shuttle Ionospheric Modification with Pulsed Localized Exhaust (SIMPLEX) experiment. SIMPLEX observed ionospheric disturbances created by Shuttle engine burns via ground radar sites and supported plume technology, plume signature, and space weather modeling.
SIMPLEX flew again on STS-110 in April 2002. STP also worked to obtain a 1-year radio frequency license extension for the Picosat experiment launched on the September 2001 Kodiak Star mission.
The satellites shared the launcher through use of an Evolved Expendable Launch Vehicle Secondary Payload Adapter (ESPA). United Launch Alliance provided a video feed of the launch.
The C/NOFS (Communications/Navigation Outage Forecasting System) satellite, which was launched on 2008-04-16, will be 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, 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-kilometer (400 mi) orbit, before the Hydrazine Auxiliary Propulsion System (HAPS) upper stage was demonstrated by deploying two ballast payloads into a 1,200 km (750 mi) orbit. The payload included the STPSat-2 spacecraft. 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.
STPSat 3 is a copy of[clarification needed] 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 November 19, 2013, on the ORS-3 Minotaur 1 launch, along with 28 CubeSats. 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.
Contract award : As announced on Tuesday, October 14, 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.
Included was COSMIC-2, a cluster of six satellites, with a mass of 277.8 kg each. 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 degrees[which?] with plans for them to move eventually to six separate orbital planes with 60 degree separation between them. 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.
STP-2 also deployed a number of CubeSats as secondary payloads, including E-TBEx, PSAT, TEPCE, and ELaNa 15 CubeSats. LightSail 2 is carried by the Prox-1 nanosatellite. Other satellites and payloads included Oculus-ASR nanosatellite, GPIM, and the Deep Space Atomic Clock.
The STP-3 mission was scheduled to be launched on a ULA Atlas V 551 rocket in 2020. Now scheduled for April 2021. It includes the STPSat-6 satellite with the NASA's Space and Atmospheric Burst Reporting System-3, NASA's Laser Communications Relay Demonstration payload, and six secondary payloads for the US Air Force. STPSat-6 is destined for an orbit slightly above the geostationary orbit. SpaceX bid a Falcon Heavy in December 2016 for this launch.