The Space Development Agency (SDA) has renamed its proliferated LEO constellation as the Proliferated Warfighter Space Architecture, or PWSA. Logo: SDA

The Department of Defense (DoD) says that the U.S. Space Force’s Space Development Agency (SDA) has met the “minimum viable product” (MVP) standard for the agency’s Proliferated Warfighter Space Architecture Tranche 0 Transport Layer communications satellites and Tracking Layer missile warning satellites, but a Government Accountability Office (GAO) report said that four evaluated contractors for the Tranche 0 satellites have only met standards four times out of 32 in eight optical communications terminal (OCT) categories.

SpaceX hit the mark three times–in the category of Tracking Layer space-to-space laser links among SpaceX satellites in the same orbital plane, Tracking Layer space-to-space data transmission among SpaceX satellites in the same orbital plane, and Tracking Layer space-to-ground laser links.

York Space Systems passed muster in the Transport Layer space-to-space laser links among York satellites, while Lockheed Martin and L3Harris Technologies did not hit any of the marks, according to the GAO report, Laser Communications: Space Development Agency Should Create Links Between Development Phases (GAO 25-106838).

“SDA has met the MVP for [Tranche o], which is to demonstrate the feasibility of the proliferated architecture in cost, schedule, and scalability towards necessary performance for beyond line of sight targeting and advanced missile detection and tracking,” the Pentagon wrote on Feb. 6 in response to the GAO report. “SDA’s MVP for the [Tranche 0] Transport Layer includes periodic regional access for low latency data connectivity, data directly to tactical elements, and data disseminated to theater targeting cells.”

“[Tranche O] validates our approach and achieved stated objectives: Link-16  from space-to-ground, air, and sea; and forming an optical network in low Earth orbit for both the Transport and Tracking Layers,” DoD said. “SDA continues to incorporate lessons from [Tranche 0] into [Tranche 1], Tranche 2, and future tranches.”

Yet, former SDA Director Derek Tournear, who is on administrative leave, said in October “that SDA is no longer planning to develop an MVP, rather that the agency considers the MVP to be equivalent to the MVC [minimum viability capability].”

GAO said that an example of MVC would be the amount of global coverage expected for a satellite constellation, while MVP would be the number of satellites required to provide such coverage.

OCT laser links among satellites built by different companies has been a point of concern and one that DoD has sought to alleviate with the Enterprise Management and Control effort.

SDA developed an OCT standard of 2.5 gigabits per second data transmission —“relatively lower than some commercial technologies that transmit data at 100 gigabits per second,” according to GAO.

“DoD officials stated that the lower rate was due, in part, to the need to conform to DoD data encryption requirements, which do not support the higher data rates,” the report said.

The OCTs are to accelerate communications with military forces in the field significantly, compared to traditional radio frequency communications.

COVID-19 related supply chain problems, such as with electronic boards, slowed the efforts of SDA, which has had two-year “tranche” advanced system development/fielding cycles under fixed price contracts as the agency’s lodestar.

“While SDA has taken considerable steps to prioritize speed, this has had consequences,” according to the new GAO report, adding that “SDA does not yet fully understand what will and will not work in [Tranche 0].”

“Without demonstrating key laser communications technology capabilities, or MVPs, SDA is risking not being able to leverage past experiences into the investments either under contract or planned for in the future,” GAO said. “These investments are substantial–nearly $35 billion.”

This story was first published by Defense Daily