WASHINGTON — The Missile Defense Agency confirmed that a national security space mission that had been projected to launch in December 2023 is being delayed until the second quarter of 2024 due to technical issues with one of the spacecraft.

“One vendor’s space vehicle was ready to support a December 2023 launch; however, the launch was delayed to no earlier than the second quarter of fiscal year 2024 due to technical issues encountered by the other vendor during final integration testing,” MDA spokesman Mark Wright said in a statement. 

MDA’s national security mission, designated USSF-124, includes six satellites designed to track hypersonic missiles. Four of the satellites are missile-tracking sensors made by L3Harris for the Space Development Agency’s Tracking Layer constellation. The other two satellites — one made by L3Harris and the other by Northrop Grumman — are part of MDA’s Hypersonic and Ballistic Tracking Space Sensor (HBTSS) program.

The Tracking Layer is envisioned as a global network of sensors to provide a defense shield against Russian and Chinese ballistic and hypersonic missiles. While SDA’s satellites are for tracking hypersonic threats, the HBTSS has sensors designed to maintain high-fidelity tracks of the threats, and to hand off the data to interceptor missiles that would attempt to shoot them down. 

Both the Tracking Layer and HBTSS are pieces of a planned multi-layered missile-defense architecture. The fire control technology that HBTSS is seeking to demonstrate is required to be able to intercept hypersonic weapons. 

SDA and MDA decided to combine their payloads for efficiency. The four L3Harris Transport Layer satellites were originally scheduled to launch in September with other SDA satellites but were taken off the manifest due to production delays. 

MDA did not disclose which of the two HBTSS payloads is having technical issues. A source close to SDA said “any delay at this point is not related to the L3Harris” Tracking Layer satellites. 

USSF-124 will launch to a low orbit on a SpaceX Falcon 9 rocket from Cape Canaveral Space Force Base, Fla.

Congressional scrutiny

The joint MDA-SDA launch comes as congressional defense committees continue to pressure the Pentagon to clarify the responsibilities of each agency when it comes to missile tracking.

“Hypersonic defense is critical to our national security, and bureaucracy should not get in the way,” said Rep. Doug Lamborn (R-Colo.), chairman of the House Armed Services’ strategic forces subcommittee. “I look forward to continuing to work with MDA and SDA to ensure HBTSS is fielded expeditiously,” he said in a social media post.

Some lawmakers have suggested SDA, which was established in 2019 to rapidly develop and launch next-generation space capabilities, should take over the mission entirely from MDA. Others argue MDA needs to retain that authority due to its decades of experience tracking ballistic missiles.

Kelley Sayler, a defense analyst at the Congressional Research Service, noted in a report earlier this year that one of the issues to watch is how MDA and SDA work together even though they report to different bosses. MDA is part of the office of the undersecretary of defense for research and engineering, whereas SDA reports to the U.S. Space Force chief of space operations, and to the Assistant Secretary of the Air Force for Acquisition and Integration.

“Congress may monitor the implications of this reporting structure for efficiency and efficacy,” Sayler wrote.

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...