Summary: The U.S. Space Force successfully launched the Department of War’s (DoW) Space Test Program S29A (STP-S29A) mission aboard a Minotaur IV rocket from Vandenberg Space Force Base, Calif. This mission delivered the the STPSat-7 space vehicle housing five DoW experiments and additional research CubeSats into low Earth orbit (LEO).
EL SEGUNDO, Calif. -- The U.S. Space Force’s (USSF) Space Systems Command (SSC) launched the U.S. Department of War’s (DoW) Space Test Program S29A (STP-S29A) mission aboard a Minotaur IV launch vehicle from Space Launch Complex 8 at Vandenberg Space Force Base, Calif., at 4:33 a.m. PDT, April 7, 2026.
This flight was the second STP mission to launch in four months, highlighting SSC’s continuing efforts to develop and test new technologies leading to the next generation of space capabilities. The DoW’s STP, managed by SSC’s System Delta 89 (SYD 89), will oversee on-orbit operations.
The primary payload aboard the mission was STPSat-7, an Evolved Expendable Launch Vehicle (EELV) Secondary Payload Adapter (ESPA) class satellite designed and built by the DoW Space Test Program (STP). DoW STP is headquartered at Kirtland Air Force Base, New Mexico, with an Operating Location at the National Aeronautics and Space Administration’s (NASA) Johnson Space Center in Houston, Texas.
The co-prime on this mission is a pair of U.S. Army-sponsored CubeSats called Rawhide. Secondary payloads onboard are MISR-C, CANVAS, AggieSat6, and ASTRA-HyRAX. DoW-STP plays a critical role in advancing space technology by providing experimental demonstration opportunities and rapid access to space for research and development projects.
“The successful launch of STP-S29A directly answers the call for a stronger, more capable military and underscores the critical role of the Space Force in deterring future conflicts,” said USSF Lt. Col. Brian Shimek, system program manager and director for STP. “The space domain is where we can and must maintain our strategic advantage. This mission is a clear demonstration of that principle in action.”
“The advanced experiments on board will provide invaluable data, enhance our space domain awareness, and ensure we continue to outpace our adversaries,” said Shimek.
The launch service was procured and led by SSC System Delta 80’s (SYD 80) Small Launch and Targets Division under its the Rocket System Launch Program (RSLP), which the department’s dedicated organization for small experimental, test, target, and responsive launch solutions.
“This launch, made possible through our strong partnership with the Rocket System Launch Program, is a vital step in building the next generation of space capabilities required to secure our nation's future. I am extremely proud of the team that executed this mission with the sense of urgency our strategic environment demands.”
With multiple pathways to efficiently launch capability on orbit, RSLP has supported more than 740 launches to date.
“Fantastic launch today from Vandenberg Space Force Base with our Space Test Program, Northrop Grumman, and SLD 30 teammates,” said USSF Lt. Col. Steve Hendershot, system program manager for RSLP. “Every mission has its unique challenges, and this one is no exception, and it’s a thrill to tackle them from mission design to spacecraft separation,”
Hendershot added that the launch profile was adapted for payload composition, trajectory, and a very specific separation timing to satisfy the individual satellite needs.
“It’s highly technical, exciting, and is what attracts talented folks to the Space Force…and being part of a successful launch that delivers capability on orbit is our reward,” Hendershot said.
RSLP used the Orbital Services Program (OSP-4), a highly flexible Indefinite Delivery, Indefinite Quantity (IDIQ) contract used to provide launch services for military payloads over 400 lbs. to any orbit.
“RSLP launches from sites around the globe, including Pacific Spaceport Complex-Alaska at Kodiak, MARS at Wallops Flight Facility in Virgina, Cape Canaveral and here at Vandenberg…we can launch wherever, whenever the mission needs,” said Sean Mussell, RSLP’s STP-S29A mission manager.
Northrop-Grumman is the launch service contractor and is responsible for providing the Minotaur IV launch service for the STP-S29A mission. The initial value of the launch service was $29.9M when awarded in September 2022. The last Minotaur IV launch occurred one year prior, also from SLC-8 at Vandenberg.
The STP-S29A mission is the 308th mission for DoW’s STP. Throughout its 58-year history STP missions have supported the development of technology behind all critical Space Force capabilities such as satellite communications, positioning, navigation, and timing, space sensing, space domain awareness, and space access.
Once on orbit, the Space Test Program will operate STPSat-7 from Johnson Space Center, Houston, TX. The spacecraft was developed using common platform avionics deployed to the International Space Station in their H-series missions as well as using commercial ground antenna infrastructure. The five experiments comprising the mission are:
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The Naval Information Warfare Centers’ NanoUHF Comms will demonstrate military SATCOM capability for proliferated Low Earth Orbit (pLEO) constellations. It will provide crucial beyond-line-of-sight (BLOS) communication and message broadcast services, significantly extending the operational reach of naval forces. A key innovation is the payload's ability to perform real-time Doppler compensation while in orbit. This feature allows existing Navy radio systems to seamlessly connect with LEO satellites, overcoming the frequency shifts caused by high-speed satellite movement.
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The Naval Research Laboratory's GAgg Radiation Instrumentation-1C (GARI-1C) follows the GARI program in the goal of space qualifying the Gd3(Al,Ga)O12 (GAGG) scintillator for space-based defense applications. The detector technology offers improved energy resolution, lower power consumption and reduced size compared to similar systems. The experiments represent teamwork across the services, and stem from a collaboration between the DoW Space Test Program, the U.S. Naval Research Laboratory (NRL), Naval Information Warfare Center- Pacific (NIWC-PAC), and the Air Force Research Laboratory (AFRL).
Secondary payloads, once in orbit, will be operated via their respective sponsors and serve a myriad of defense and academic research programs:
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The Department of War's MISR-C satellite program uses 16U CubeSats to demonstrate responsive, multi-mission capabilities, including testing two-way communications with ground devices and exploring novel tactical applications for small satellites. This program is the third in a series of missions to prove the effectiveness and versatility of CubeSat technology for the DoW.
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ASTRA-HyRAX, built by Auburn University and funded by the Army’s Space and Missile Defense Command, is the newest mission under development in AUSSP. The mission aims to use a hybrid retro directive array (HRA) payload developed at Auburn to characterize the direction of signals from targets of opportunity.
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AggieSat6 is developed by students at Texas A&M University, in partnership with the Air Force Research Laboratory, to demonstrate new space domain awareness technology for tracking other satellites using commercial off-the-shelf components. The results from the payloads will be collected after the on-orbit test period is complete and will be fed back into various development pipelines for future capabilities.
Space Systems Command is the U.S. Space Force field command responsible for acquiring, developing, and delivering resilient capabilities to outpace emerging threats and protect our Nation’s strategic advantage in, from, and to space. SSC manages a $15.6 billion annual space acquisition budget for the Department of War, working with joint forces, industry partners, government agencies, academia, and allied nations.
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Media representatives can submit questions regarding this topic to sscpa.media@spaceforce.mil.