Defense Meteorological Satellite System (DMSP) spacecraft. Credit: U.S. Air Force Credit: U.S. Air Force
By Sandra Erwin,
Published by Space News, 21 November 2023
WASHINGTON — The U.S. Space Force is on track to launch at least two weather monitoring satellites next year while determining a long-term replacement for its aging fleet that currently supplies essential yet insufficient environmental monitoring.
In the coming years, some capacity will come from U.S. military-owned satellites but DoD planners and weather analysts for the most part will use data from the National Oceanic and Atmospheric Administration (NOAA), Europe’s Eumetsat, the Japan Meteorological Agency and other partners, officials said Nov. 20.
Col. Patrick Williams, director of weather for the U.S. Air Force, said the military can no longer rely on the aging Defense Meteorological Satellite Program (DMSP) constellation. Only two are still functioning, and their limited observational capabilities are insufficient for modern military missions, Williams said at a Mitchell Institute for Aerospace Studies event.
The Mitchell Institute on Monday released a report criticizing DoD’s lagging efforts to recapitalize its environmental monitoring satellites. “For over 20 years, multiple incomplete replacement programs have resulted in this capability gap as DMSP comes to its end of life,” said the author of the report, senior fellow Tim Ryan.
DMSP satellites in sun-synchronous low Earth polar orbits carry sensors to measure parameters like cloud cover, precipitation, temperature, and moisture in the atmosphere. They are used by the Air Force Weather Agency and other organizations to generate environmental analysis and forecasting models needed for planning aviation missions, ship routing, missile testing and other military operations.
“There are not enough DMSPs to give us enough of a refresh rate,” Williams said. “So it might as well be a dead constellation at this point.”
Ryan in the report lays out several unsuccessful efforts by the Air Force over the past two decades to replace DMSPs. “Knowing DMSP is on its last legs, leaders are augmenting U.S. capabilities with a family-of-systems approach that combines data from other sensors on orbit through partnerships with NOAA and U.S. allies,” he said. But he called this a “band aid” that does not address certain coverage requirements and refresh rates that are “very military specific.”
New programs in the works
Under a program called EWS, short for Electro-Optical/Infrared (EO/IR) Weather Systems, the Space Force plans to launch a prototype cubesat in 2024 and a small EO/IR satellite in 2025 that would perform similar functions as DMSP.
It also plans to launch in 2024 the first of two Weather System Follow-on Microwave, or WSF-M satellites. These will collect data on the conditions of the ocean surface and other atmospheric conditions.
Ryan argued that these projects are not moving fast enough and noted that there is still no long-term plan to procure a constellation of EO/IR satellites. To get a one-hour refresh rate, he noted, requires 12 satellites.
The EWS should be a top priority, said Ryan, because the military needs accurate data on cloud cover to launch munitions, and intelligence agencies rely on that data to plan satellite imagery collections.
Williams said the Air Force, which manages weather data collection and analysis for the U.S. military, has established agreements with many partners to ensure demands are met. “We don’t always have all the assets that we need when we need them. So we need others to help us out,” he said. “And until we can have our own reliable, relevant data at our fingertips, we have to rely on others.”
“There’s a danger in that,” he said. “But right now, they’re all willing participants, so that’s a good thing.”
The Space Force recently took ownership of a retired NOAA weather satellite to fill gaps in coverage over the Indian Ocean.
DMSP has ‘a few more years’
Lt. Col. Joseph Maguadog, materiel leader for weather systems at Space Systems Command, said the remaining DMSP satellites still have a “a few more years of life.”
Maguadog’s office oversees the EWS program. Studies are underway to determine the most appropriate solution to replace DMSP, he said at the Mitchell Institute event.
The U.S. military is getting the data it needs via “a family of systems with our partners and NOAA, the European Meteorological Agency, the Japan Meteorological Agency,” he said. “And the only way that we are going to deliver the refresh rates that our DoD operators need today is to continue to work within that family of systems.”
A shoebox-size cubesat demonstration projected to launch in March 2024 is about “trying to push the bounds of how small we can make this,” Maguadog said. “There are lots of things that we’ve got to study as we’re trying to drive towards a smaller and cheaper capability.”
In 2025 the Space Force will launch a small EO/IR satellite as an “operational demonstration.”
One of the issues is how to “disaggregate” the functions of jack-of-all-trades satellites like DMSP into multiple smaller spacecraft, he said. “If our users cannot ingest the data or the data data is not operationally viable, we’re going to consider that a failure.”
The Space Systems Command is working with weather data users to make sure that an architecture of small satellites can be set up in a way that supports their needs, Maguadog said.
Regardless of what future satellites are acquired, he said, “the partnerships with NOAA our allies have and will continue to be a key to our success.”
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