By Kurtis Archer | 2025-03-12

A recent Congressional watchdog report highlights challenges in the Space Development Agency (SDA)'s ambitious Proliferated Warfighter Space Architecture (PWSA) -- a next-generation satellite network designed to enhance missile warnings, tracking and secure communications.

In a report released February 26, the US Government Accountability Office (GAO) said the SDA pushed too hard for a constellation of military missile-tracking satellites without first demonstrating the technology needed for the project.

The SDA, a semi-independent acquisition unit under the US Space Force, disputed the findings.

The main concern expressed by the GAO claims the SDA has not proven the laser communication technology needed for the PWSA constellation.

PWSA is a tactical low Earth orbit network that communicates missile warnings as well as position, navigation and timing data to "wherever it's needed on the ground as quickly and securely as possible," according to the SDA.

The laser-based communication links are necessary for the high-speed transmission of data required by the military project, but the GAO says the technology has not been sufficiently demonstrated in the harsh environment of space to push ahead without first proving that the inter-satellite communication system will work.

"SDA is moving forward with dramatic increases in the scale of future tranches even though it has made limited progress demonstrating laser communications -- a central capability for PWSA," the report said.

Baseline objectives met

Still, the SDA expressed confidence in its phased approach. It emphasized the successes already achieved and its strategy for demonstrating full capability in upcoming launches.

An SDA spokesperson on February 27 refuted some of the report's findings and asserted that the agency's approach to the project has been appropriate -- pointing out that the first batch of satellites launched under PWSA has been successful.

"While GAO is accurate in their report that we have not yet demonstrated the 'full range of laser communications,' SDA successfully met the baseline objectives set forth in Tranche 0: proving critical technology and providing lessons learned for both the government and vendor teams," the spokesperson said, according to SpaceNews.

Tranche 0 was the deployment of 27 satellites last year to test key technologies for the program.

"Accomplishments from Tranche 0 tests include successful in-plane lasercom links," the spokesperson said. "We also demonstrated the feasibility of a mesh optical network on orbit, procured through multiple vendors on abbreviated acquisition timelines, and now seek to expand our optical communication terminal (OCT) capability."

The GAO report states that while certain laser communication tests were performed, the SDA did not fully confirm the system's ability to function properly in orbit before moving onto launching the next batch of satellites.

The GAO raises the concern that a lack of complete testing in the initial phase could complicate the constellation's ability to perform as needed after more deployments in the future -- costing the roughly $35 billion program more time and money in the long run.

The SDA countered by stating that the baseline objectives for Tranche 0 were completed. It pointed out that a complete demonstration of the technology would be an impractical endeavor at such an early stage in the project.

The SDA assured that Tranche 1's launch in 2025 will see more advanced optical communication terminals and that the project will continue to demonstrate its viability.

Hundreds of satellites

The SDA has already spent about $9.5 billion awarding contracts for hundreds of satellites.

PWSA is set to have at least about 400 satellites that provide missile warning, tracking, communication and navigation services for troops wherever needed.

Using a narrow beam of light to transmit data down to Earth is 10 to 40 times faster than traditional radio communication methods, and it is much more difficult for enemies to intercept communications with these laser systems.

Lasers also allow the system to adapt and reconfigure as needed should any of the satellites malfunction or be attacked someday.

Spacecraft in low Earth orbit move at about 17,000 mph (27,359km/h) -- meaning the time windows for satellites to send each other data via lasers are relatively small. The constraints of orbital space make proving the technology even more necessary now than later, the GAO argues.

The US Department of Defense (DoD), while acknowledging the GAO's findings, confirmed that the SDA has met its revised minimum viable product for Tranche 0 and is progressing toward a fully functional system in Tranche 1.

"In Tranche 1, SDA is on track to leverage in-plane optical links to operate a fully functional system and continue work toward demonstrating the full range of laser communications to enable delivery of critical warfighting capabilities," a DoD official said.

The SDA maintains that advancing the program through incremental development cycles allows it to deliver capabilities to the military faster while refining technology along the way.