Space Test Program

STP provides spaceflight via the International Space Station (ISS), piggybacks, secondary payloads and dedicated launch services.

For example, the initial experiments that led to the modern Global Positioning System (GPS) satellite constellation were STP-launched projects.

[citation needed] In December 2001, STS-108 hosted the Shuttle Ionospheric Modification with Pulsed Localized Exhaust (SIMPLEX) experiment.

[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.

[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.

[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)".

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

[13] The primary role of the COSMIC-2 satellite constellation is to provide radio occultation data with an average latency of 45 minutes.

[22] The STPSat-4 satellite was launched on 2 November 2019 onboard the Cygnus NG-12 mission and was subsequently deployed to orbit from the ISS on 29 January 2020.

[23] The satellite hosted a variety of experimental technologies, including: iMESA-R, a USAF mission to measure plasma densities and energies; MATRS, a modular solar array that partially failed to deploy; NISTEx, an inferometric star tracker; NTE, a passive retroreflector.

[30] The CIRCE 1 and 2 cubesats were developed by the DSTL and the NRL using 6U platforms provided by Blue Canyon Technologies, and they would've flown in formation to study short-timescale dynamics in the ionosphere.

[31] The Prometheus 2A and 2B cubesats have been built by In-Space Missions for the UK Ministry of Defence and the NRO and they would've provided a test platform for monitoring radio signals.