The Space Development Agency’s effort to deploy a constellation of low Earth orbit satellites for missile warning and tracking is at risk of falling short of its goals and operational requirements, according to a new report by the Government Accountability Office released on Thursday.
The report, covering the period from October 2023 to January 2026, focuses on SDA’s Tracking Layer within its broader Proliferated Warfighter Space Architecture (PWSA). While the findings are specific to missile warning and tracking satellites, GAO said many of the challenges identified extend across SDA’s wider effort to field interconnected constellations, including data relay satellites and ground systems.
GAO said SDA has been overly optimistic about the technology readiness of several critical elements, including spacecraft being built by multiple contractors. According to the report, these systems have required unplanned modifications that added work for suppliers and contributed to schedule delays. More critically, GAO said SDA and its contractors have yet to demonstrate the ability to generate timely and accurate two-dimensional tracks in orbit and three-dimensional tracks on the ground needed to counter hypersonic and other advanced missile threats.
Although SDA has reported progress through early milestones as it develops new satellite variants in two-year increments known as Tranches, GAO said those reports do not adequately reflect schedule risks. The agency has also not developed an overarching, architecture-level schedule that would allow stakeholders to assess overall progress and interdependencies.
As of July 2025, SDA had awarded $4.7 billion in contracts for 101 Tracking Layer satellites across Tranches 0, 1 and 2 to six prime contractors, including L3Harris Technologies, Lockheed Martin, Northrop Grumman, Raytheon, Sierra Space and SpaceX. In December, the agency issued an additional $3.5 billion in contracts for 72 Tranche 3 satellites to teams led by Lockheed Martin, Rocket Lab USA, Northrop Grumman and L3Harris.
The report also highlighted uncertainty around long-term costs. Tracking Layer satellites are expected to have a service life of about five years, after which they must be replaced. GAO said the Department of Defense has not yet established a reliable life-cycle cost estimate for delivering missile warning and tracking capabilities, limiting its ability to make cost-informed decisions.
GAO further criticised SDA’s requirements-setting process, saying it lacks transparency and insufficiently involves combatant commands that will ultimately rely on the constellation. As a result, GAO warned, SDA risks delivering satellites that do not fully meet warfighter needs.
To address the issues, GAO issued six recommendations to the Office of the Secretary of the Air Force, which oversees SDA’s acquisition and budget plans. These include conducting tailored technology readiness assessments for future tranches, developing an architecture-level schedule for PWSA, improving collaboration with warfighters on requirements, and establishing reliable, data-driven cost estimates beginning with Tranche 3, which is expected to begin launches in late 2029.
In a December letter to GAO, the Department of Defense said it concurred with five of the recommendations and partially concurred with one. SDA, however, said it disagreed with several of GAO’s specific findings. “The Space Development Agency appreciates the time and the attention to detail the Government Accountability Office applied to their review,” said SDA spokesperson Jennifer Elzea, adding that the agency would review the recommendations to identify areas for improvement.
