SpaceX launches Space Force weather satellite designed to take over for a program with roots to the 1960s

The Weather System Follow-on – Microwave (WSF-M) space vehicle was successfully encapsulated April 8, 2024, ahead of its scheduled launch as the U.S. Space Force (USSF)-62 mission from Vandenberg Space Force Base, Calif., marking a major milestone on its upcoming launch into low Earth orbit. Image: SpaceX

SpaceX launched a military weather satellite designed to replace aging satellites from a program dating back to the 1960s. The United States Space Force-62 (USSF-62) mission featured the launch of the first Weather System Follow-on Microwave (WSF-M) spacecraft.

Liftoff of the Falcon 9 rocket from Space Launch Complex 4 East (SLC-4E) at Vandenberg Space Force Base happened at 7:25 a.m. PDT (10:25 a.m. EDT (1425 UTC), which was the opening of a 10-minute launch window.

The booster supporting this National Security Space Launch (NSSL) mission, B1082 in the SpaceX fleet, made its third flight after previously launching the Starlink 7-9 and 7-14 missions this year.

“We’re absolutely thrilled be out here on the Central Coast, with a superb team primed and ready to launch the USSF-62 satellite. It has an important mission ahead of it and we’re excited for flight-proven Falcon 9 to deliver the satellite to orbit,” said Col. Jim Horne, senior materiel leader for the Space System Command’s Launch Execution Delta, in a statement. “And on this mission, we’re using a first-stage booster whose history is purely commercial.”

About eight minutes after liftoff, B1082 touched down at Landing Zone 4 (LZ-4). This was the 17th land landing in California and the 295th booster landing for SpaceX.

A significant milestone for the company on the USSF-62 mission was the use of flight-proven payload fairings, which will be a first for an NSSL mission. They previously flew on the USSF-52 mission, which featured the launch of the X-37B spaceplane from NASA’s Kennedy Space Center in December 2023.

“With each national security launch, we add to America’s capabilities and improve its deterrence in the face of growing threats,” Horne stated.

USSF-62 was one of three missions granted to SpaceX in May 2022 as part of the NSSL Phase 2 Order Year 3 award, which collectively are valued at $309.7 million. SpaceX launched USSF-124 in February 2024 and will likely launch the SDA-Tranche 1 satellites later this year.

The U.S. Space Force (USSF)-62 Weather System Follow-on – Microwave (WSF-M) space vehicle was successfully transported April 9, 2024, to the Space Launch Complex-4 East (SLC-4E) at Vandenberg Space Force Base, Calif., in preparation for its upcoming launch into low Earth orbit. Image: Space Systems Command

Next-generation weather sensing

Ball Aerospace, the manufacturer of the WSF-M, said the spacecraft’s primary payload is a passive microwave radiometer, which has been demonstrated on previous spacecraft. It also boasts a 1.8 meter antenna, which combined with the primary instrument allow the spacecraft to address so-called “space-based environmental monitoring (SBEM) gaps.”

It’s capabilities will provide valuable information for protecting the assets of the United States and its allies, primarily in ocean settings.

“The WSF-M satellite is a strategic solution tailored to address three high-priority Department of Defense SBEM gaps – specifically, ocean surface vector winds, tropical cyclone intensity, and energetic charged particles in low Earth orbit,” said David Betz, WSF-M program manager, SSC Space Sensing, in a statement. “Beyond these primary capabilities, our instruments also provide vital data on sea ice characterization, soil moisture, and snow depth.”

Deployment of USSF-62’s Weather System Follow-on – Microwave Space Vehicle confirmed pic.twitter.com/M9DX2A9XOW

— SpaceX (@SpaceX) April 11, 2024

The spacecraft is “based on the Ball Configurable Platform” and includes a Global Precipitation Measurement (GPM) Microwave Imager (GMI) sensor and an Energetic Charged Particle sensor. Ball Aerospace has been involved with other, similar spacecraft, including the Suomi National Polar-orbiting Partnership (Suomi-NPP) and the Joint Polar Satellite System-1 (JPSS-1).

According to a public FY2024 Department of Defense budget document, the WSF-M system will consist of two spacecraft. Once the first is on orbit, it will assess the level of Ocean Surface Vector Wind (OSVW) measurement uncertainty and Tropical Cyclone Intensity (TCI) latency.

The first seeds of the program were planted back in October 2012 during what’s called the Materiel Solution Analysis phase. That resulted in the Department of the Air Force issuing a request for proposals from companies in January 2017.

In November 2017, the Space and Missile Systems Center (now Space Systems Command) awarded a $93.7 million firm-fixed-price contract to Ball Aerospace for the WSF-M project with an expected completion date of Nov. 15, 2019.

“This is an exciting win for us, and we’re looking forward to expanding our work with the Air Force and continuing to support warfighters and allies around the world,” said Rob Strain, the then president, Ball Aerospace, in a 2017 statement. “WSF-M extends Ball’s legacy of providing precise measurements from space to enable more accurate weather forecasting.”

Roughly a year later, Ball received a $255.4 million contract modification, which “provides for the exercise of an option for development and fabrication of the [WSF-M] Space Vehicle 1.” This new contract also pushed out the expected completion date to Jan. 15, 2023.

In May 2020, the U.S. Space Force’s SMSC noted the completion of the WSF-M system’s critical design review that April, which opened the door to the beginning of fabrication.

Ball Aerospace completed the first of two Weather System Microwave-Follow-on (WSF-M) satellites for the U.S. Space Force Space Systems Command as of Sept. 7, 2023. Image: Ball Aerospace

Over the following year, the spacecraft went through a series of tests, running both the software and hardware through its paces. The primary bus structure was completed by August 2021 and by October 2022, the spacecraft entered its integration readiness review (IRR) and test readiness review (TRR).

Before that though, in May 2022, Ball was awarded a $16.6 million cost-plus-incentive-fee contract modification, which was “for the exercise of an option for integration, test and operational work” of the spacecraft. That brought the cumulative face value of the contract to about $417.4 million.

Shortly before the end of that year, in November 2022, Ball received a $78.3 firm-fixed-price contract modification to develop the second WSF-M spacecraft. That work is expected to be completed by Nov. 15, 2027, which would set up a launch opportunity no earlier than January 2028.

It was finally delivered from Ball’s facilities in Boulder, Colorado, to Vandenberg Space Force Base for pre-launch processing in February 2024.

“This delivery represents a major milestone for the WSF-M program and is a critical step towards putting the first WSF-M satellite on-orbit for the warfighter,” said Col. Daniel Visosky, senior materiel leader, SSC’s Space Sensing Environmental and Tactical Surveillance program office, in a statement. “It represents a long-term collaboration and unity-of-effort between the Space Force and our combined teams at Ball Aerospace, support contractors and government personnel.”

The WSF-M satellite is on its way to the Space Vehicle Processing Center, where it will undergo a series of post-shipment functional tests. Image: Airman 1st Class Ryan Quijas/U.S. Space Force

Out with the old, in with the new

This first WSF-M satellite, and eventually the second, will take the place of the legacy Defense Meteorological Satellite Program (DMSP) satellites, which have roots going back in the 1960s. The program features two primary satellites, which operate in sun-synchronous LEO polar orbits at about 450 nautical miles in altitude.

Originally known as the Defense Satellite Applications Program (DASP), the first of these legacy satellites launched in 1962 and they were classified under the purview of the National Reconnaissance Office (NRO) as part of the Corona Program. The DMSP was declassified in 1972 to allow data to be used by non-governmental scientists and civilians.

Artist’s concept of a DMSP weather satellite in orbit. Credit: Lockheed Martin

According to a Space Force historical accounting, a tri-agency organizational agreement was forged between the DoD, the Department of Commerce and NASA following President Bill Clinton’s directive for the DOC and the DoD “to converge their separate polar-orbiting weather satellite programs.” Funding responsibility stayed with the DoD, but by June 1998, the operational responsibility of the DMSP transferred to the Department of Commerce.

Satellite operations for the DMSP then became the responsibility of the National Oceanic and Atmospheric Administration (NOAA) Office of Satellite and Product Operations (OSPO).

The program was not without issue over the years. In 2004, the DMSP-F11 satellite, launched in 1991 and retired in 1995, disintegrated and created dozens of pieces of orbital debris. In 2015, a faulty battery was blamed for a similar disintegration of DMSP-F13, which resulted in 147 pieces of debris.

That year, Congress ordered an end to the DMSP program and the yet-to-launch F20 satellite was to be scrapped.

In February 2016, the DMSP-F19 had its planned five-year mission cut short less than two years after launch. The satellite suffered a power anomaly that caused engineers to lose control of it. The spacecraft was declared lost in March.

The DMSP-F17 satellite, launched in 2006, was then relocated to the primary position vacated by F19. According to the Observing Systems Capability Analysis and Review (OSCAR), a tool developed by the World Meteorological Organization, there are three DMSP satellites still in service: F16, F17 and F18. They launched in 2003, 2006 and 2009 respectively.

The latter two have expected end-of-life dates of 2025, with F16 intended to conclude its mission in December 2023, according to the Committee on Earth Observation Satellites (CEOS). However, that expiration has been extended as the WSF-M replacements are still on the way.

It’s unclear if F17 and F18 can hang on until the second WSF-M spacecraft is completed and launched in 2028.

A rendering of the WSF-M Space Vehicle. Graphic: Ball Aerospace