THE WATCH STAFF
The U.S. Space Development Agency (SDA) plans to have satellites deployed by 2025 that can identify hypersonic weapons in flight.
The satellites will make up the low-Earth orbit (LEO) “tracking layer” of an eventual National Defense Space Architecture (NDSA).
The satellites will detect hypersonic threats by the weapons’ heat signatures, said Dr. Derek Tournear, the SDA’s director, during the Schriever Spacepower Forum hosted January 12, 2022, by the Mitchell Institute for Aerospace Studies.
An ultrafast hypersonic glide vehicle (HGV) can take advantage of blind spots in current radar networks because — unlike traditional ballistic missiles — it can maneuver on the way to its target.
The HGVs are boosted to near-space altitudes by rockets, then “divert to a flatter trajectory —either exiting the atmosphere or staying just within it — and sail on unpowered,” according to a January 18 story in Scientific American magazine. “They use aerodynamic lift to skip across the atmosphere to their targets at hypersonic speeds.”
The launch of the missiles can be detected, but the HGV “slips out of view until late in the weapon’s flight because of ground radar’s line-of-sight limitations,” which results in little time, if any, for defense, according to Scientific American.
“That’s one of the big advantages of the LEO,” Tournear said of the position of the tracking-layer satellites, pictured.
The U.S. is developing hypersonic weapons with the goal of deployment in 2023. Russia and the People’s Republic of China have fielded hypersonic missiles.
Tournear said that satellites in LEO can better detect heat signatures.
“In the lower orbit, we can actually detect signatures that are … essentially dimmer than what you can detect in these higher orbits,” Tournear said, according to a January 12 Air Force Magazine story. Targets become detectable not just at launch, “but you can [also] see the hypersonic glide vehicles as they’re maneuvering and getting hot.”
Twenty-eight satellites launched in 2024 and 2025 will form the “kernel” of the tracking ability, Tournear said, according to Air Force Magazine. He said the advantage of having numerous satellites is they will be able to “calculate the three-dimensional track very accurately.”
When a threat is detected, the data will be sent to satellites in the “transport layer” of the NDSA via laser-optical cross links, which can rapidly move large amounts of data, according to a January 12 story by the Department of Defense News.
“The transport satellites are the backbone of the National Defense Space Architecture,” Tournear told Department of Defense News on October 5, 2020. “They take data from multiple tracking systems, fuse those, and are able to calculate a fire-control solution, and then the transport satellites will be able to send those data down directly to a weapons platform via a tactical data link, or some other means.”
The NDSA plans call for 144 transport layer satellites to be launched by September 2024, according to the Department of Defense. By 2025, 28 tracking layer satellites will be launched, resulting in global coverage, the DOD said.
During the Schriever Spacepower Forum, Tournear also confirmed that SDA, which was created in 2019, will be transferred to the U.S. Space Force in 2022.
IMAGE CREDIT: U.S. SPACE DEVELOPMENT AGENCY