Are Defense Satellites Ready for Space-Based Laser Communications?

March 5, 2025

In September, the Space Development Agency (SDA) published this conceptual image of satellite crosslinks using lasers after demonstrating the ability of its optical communications terminals to link satellites together. (Image: SDA)

The Department of Defense (DoD) is developing technology for satellites to communicate via lasers. Laser communications could transmit data faster and more securely than traditional radio frequency communications.

DoD has made progress in developing this technology, but it also faced delays and other issues—and hasn't fully demonstrated that it works in space. Despite these challenges, DoD plans to continue to develop and launch hundreds of satellites worth billions of dollars that require the use of laser communications.

In a 56-page report published in late February, the Government Accountability Office (GAO) made four new recommendations that would help DoD demonstrate the viability of space-based laser communications before investing in further development of the unproven technology.

What GAO Found

The Space Development Agency (SDA) has taken steps to develop laser communications technology but has not yet fully demonstrated it in space. SDA has planned for iterations of satellites and related systems to be launched every 2 years, referred to as tranches. SDA's demonstration tranche — referred to as Tranche 0 or T0 — has faced development challenges and delays and has not fully demonstrated the capabilities expected from it.

For example, SDA planned to launch the first T0 satellites in 2022 but launched them in 2023 and 2024. Further, this initial group of satellites has not yet fully demonstrated laser communications technology in space. Specifically, as of December 2024, SDA reported that one of its four prime contractors in T0 had demonstrated three of the eight planned laser communications capabilities while another contractor had demonstrated one of the eight capabilities. The remaining two contractors have not yet achieved any planned capabilities.

SDA's development approach thus far is inconsistent with the leading practices GAO identified. For example, although it has not yet achieved its requirements established for T0, SDA has now awarded contracts worth almost $10 billion for Tranche 1 and Tranche 2 (referred to as T1 and T2). Further, these two new tranches are expected to include increased technology complexity and significantly more satellites. While T0 was planned with 28 satellites, T1 and T2 are to have 165 and 264, respectively.

According to GAO's leading practices for product development, iterative development depends on demonstrating necessary capability in each iteration. SDA has described its efforts as iterative and noted that tranches need to work together to create the laser-based constellations. However, SDA officials also said that tranches are independent and delays in one will not delay the development schedule of future tranches. This approach means that SDA is proceeding through tranches and increasing the complexity of its development based on designs that have not yet met initial capabilities. As a result, SDA is at risk of unnecessarily investing in new efforts without yet delivering on promised capabilities intended to support critical missions.

A generic depiction of an optical communications terminal illustrated by GAO. (Image: GAO)

Why GAO Did This Study

DoD is in the early stages of developing a new way to communicate in space, using laser technology. According to department documents, DoD has traditionally relied on radio frequency — electromagnetic waves that transmit data over a specific frequency — to communicate between satellites and with receivers on the ground or sea or in the air. Specifically, like radio frequency, laser communications can be used to transmit data from space-to-space; space-to-ground, such as to ground stations or ships at sea; and space-to-air, such as to aircraft in flight. According to DoD documentation and laser communication technology developers, laser communications are an alternative to using radio frequency to transmit data in space and are capable of communicating at a rate 10 to 40 times higher than radio frequency data transmission rates, using a beam of light that is about 1,000 times narrower. This narrower beam means that laser communications have a far smaller “footprint” or area in which a receiver can receive data. This limits the potential for adversaries or others to intercept the signal.

A Senate report includes a provision for GAO to assess DoD's efforts to develop these capabilities. GAO's report (1) describes SDA's efforts to develop laser communications technology, and (2) evaluates the extent to which SDA is following leading product development practices for its laser communications efforts.

GAO reviewed relevant documents; assessed SDA's schedule and plans against leading acquisition practices; conducted site visits to Air Force Research Lab, Naval Research Lab, and contractor facilities; and interviewed DoD, SDA, and Space Force officials and contractor representatives.

GAO's four recommendations, including that SDA demonstration laser communications capabilities before finalizing efforts in T0 and before making further investments in subsequent tranches, are outlined below:

The Secretary of the Air Force should ensure that the Director of the Space Development Agency demonstrates the minimum viable product for laser communications capability in space in PWSA's T0 and incorporates relevant lessons learned and corrective updates before proceeding with launch decisions for satellites in T1.
The Secretary of the Air Force should ensure that the Director of the Space Development Agency creates and documents a link between demonstrating the minimum viable product for laser communications capability in space in PWSA's T1 and incorporates relevant lessons learned and corrective updates before proceeding further with launch decisions for satellites in T2.
The Secretary of the Air Force should direct the Director of the Space Development Agency to ensure investment in PWSA is commensurate with development progress by demonstrating the minimum viable product of laser communications in space and incorporating lessons learned and corrective updates in T1 and, to the extent practicable, T2 before proceeding with the T3 effort.
The Secretary of the Air Force should direct that the Director of the Space Development Agency documents and communicates PWSA's T0, T1, T2 and future tranche on-orbit test plans, including timelines and results, to relevant stakeholders.

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