WASHINGTON — SpaceX launched a U.S. military classified mission Feb. 14, sending to orbit six missile-detection satellites: two for the Missile Defense Agency and four for the Space Development Agency.

The mission, named USSF-124, flew to low Earth orbit on a Falcon 9. The rocket lifted off at 5:30 p.m. Eastern from Launch Complex 40 at Cape Canaveral Space Force Station, Florida.

The payload included five satellites made by L3Harris Technologies and one made by Northrop Grumman. 

The upper stage separated from the booster just over two minutes after liftoff. The first stage landed back on Landing Zone 2 at Cape Canaveral Space Force Station. After the landing, at the request of the government, SpaceX ended the webcast and did not show any images of the payload. 

USSF-124 was the 11th mission flown by SpaceX under the National Security Space Launch program, and the second under the NSSL Phase 2  contract

Two of the satellites — one from L3Harris and the other from Northrop Grumman — are the first prototypes developed under the Missile Defense Agency’s Hypersonic and Ballistic Tracking Space Sensor (HBTSS) program.

The other four L3Harris satellites are part of the Space Development Agency’s Tracking Layer Tranche 0. These are demonstration satellites that will provide test data as SDA continues to build a large constellation for global indications, warning, tracking, and targeting of missile threats.

MDA is a Defense Department agency. SDA, a U.S. Space Force organization, is building a space network — called the Proliferated Warfighter Space Architecture — that includes a transport layer and a missile-tracking sensor layer. 

Both agencies are collaborating to develop a sensor network for tracking both hypersonic and ballistic missiles.

All six satellites on USSF-124 were delivered to their intended orbit, the Space Systems Command said late Wednesday.

Credit: Space Systems Command

“They are all in the same plane in a near equatorial orbit and will work together to do demonstrations,” SDA said. “We’ll take Tranche 0 wide-field-of-view satellites and use that data to cue HBTSS satellites. That will help inform what we do in future tranches.”

“This launch represents a pivotal time for MDA as we enter a new phase of missile warning, tracking and defense,” said Lt. Gen. Heath Collins, director of MDA.

The USSF-124 mission launched the four remaining satellites of Tranche 0 of SDA’s proliferated satellite architecture. The agency launched 23 other Tranche 0 satellites last year in April and December. 

“Launching our tracking satellites into the same orbit with the MDA HBTSS satellites is a win for both agencies,” said Derek Tournear, director of SDA. “We’ll be able to look at test targets from the same orbit at the same time, so that we can see how the two sensors work together.”

SDA’s satellites have so-called wide-field-of-view sensors, designed to detect the heat signature of a missile launch and identify whether it’s a legitimate threat. 

MDA’s medium-field-of-view payloads are designed to provide “fire control quality” data needed to precisely follow the missile’s trajectory throughout its flight path and provide continuous updates on location,speed and altitude. This detailed information is crucial for accurately predicting impact points and for aiming interceptor missiles at hypersonic threats, which are much faster and maneuverable than traditional ballistic missiles.

A big deal for L3Harris

Simultaneously launching missile-defense satellites for two different programs marks a significant milestone for L3Harris, which for years has sought to position itself as a military satellite prime contractor to challenge dominant players like Northrop Grumman and Lockheed Martin.

“This is our first missile-defense mission with L3Harris as a prime,” Kelle Wendling, the company’s president of space systems, told SpaceNews.

To develop these satellites, the company used infrared imaging technology developed over decades for weather imaging and Earth science missions for agencies like NASA and the National Oceanic and Atmospheric Administration. 

“The same phenomenology can be applied to detect the heat signatures of hypersonic missiles,” said Wendling. 

She said L3Harris currently has a backlog of 50 satellites on order, including 34 for SDA’s Tracking Layer Tranches 1 and 2. 

Sandra Erwin writes about military space programs, policy, technology and the industry that supports this sector. She has covered the military, the Pentagon, Congress and the defense industry for nearly two decades as editor of NDIA’s National Defense...