Windsat. Credit: National Research Laboratory

WASHINGTON — The U.S. Air Force’s proposed next-generation weather satellite program will consist of a single satellite carrying three instruments that would launch in 2021 or 2022, a service official said Nov. 7.

In a speech here at the Capitol Hill Club, Col. Heath Collins, deputy director of the remote sensing directorate at the Air Force Space and Missile Systems Center at Los Angeles Air Force Base, offered previously unpublicized details of the service’s Weather Satellite Follow-on program, saying the service would rely on the system to fill three main data requirements: ocean-surface wind speed and direction, tropical cyclone intensity, and charged particles in low Earth orbit with the potential to affect satellites.

In a recently completed analysis of alternatives for its weather satellite program, the Air Force identified nine other data products the military depends on but said this information is available from international or civil satellites, Collins said. The study itself is classified.

Key among the data products needed from a dedicated military weather satellite is ocean-surface wind vector information to support naval sea and air operations. Collins said the Air Force wants to get that capability into orbit “as fast as we can.”

The urgency stems in part from the fact that the Defense Department’s current source of ocean-wind vector data, the Windsat microwave polarmetric radiometer aboard the Naval Research Laboratory’s Coriolis satellite, is nearing the end of its life. Coriolis was launched in 2003.

The Defense Department warned Congress in an October memo that it could be facing a gap in ocean-surface wind data beginning in early 2015.

According to a U.S. Navy fact sheet, Windsat data are used for precision guidance, avoiding fallout from nuclear, biological and chemical attacks, routing ships, avoiding tropical cyclones, and search and rescue operations.

The Air Force is hoping to cobble together an interim capability based on analyzing data from other sensors using improved algorithms.

Collins said the acquisition strategy for the first satellite in the new program is expected to be completed by the end of the year, with a decision to enter development expected in 2015. He said the Air Force is considering buying the satellite and one or more replacements simultaneously, an approach that typically garners a better unit price.

Documents accompanying the Air Force’s 2015 budget request said the Weather Satellite Follow-on program comprises “a group of systems to provide timely, reliable, and high quality space-based remote sensing capabilities that meet global environmental observations of atmospheric, terrestrial, oceanographic, solar-geophysical and other validated requirements.”

Air Force officials have said a dedicated satellite could be small enough to launch on one of its Minotaur line of rockets, which utilize excess missile motors.


The Air Force requested $39 million for the Weather Satellite Follow-on program in 2015. The Senate Appropriations Committee recommended providing that full amount in its version of the 2015 defense spending bill, but the House version of that legislation proposed just $5 million.

Funding for the Weather Satellite Follow-on program next year likely is linked to a pending decision on whether to proceed with the launch of the last of the Air Force’s legacy weather satellites, which was built in the 1990s.

Collins said a decision on the fate of that satellite, known as Defense Meteorological Satellite Program-20, awaiting finalization by the deputy secretary of defense.

Mike Gruss covers military space issues, including the U.S. Air Force and Missile Defense Agency, for SpaceNews. He is a graduate of Miami University in Oxford, Ohio.