The Senate’s annual defense policy bill would authorize an additional $120 million toward a space-based sensor layer capable of tracking hypersonic weapons, despite the fact the Department of Defense did not seek more funding for the project in its fiscal 2021 budget requests.

The Hypersonic and Ballistic Tracking Space Sensor is DoD’s answer to the growing threat posed by hypersonic weapons being developed by China and Russia. Hypersonic weapons present a significant challenge to the United States’ current missile warning architecture. Not only can these weapons maneuver around ground based sensors, they’re too dim to be picked up and tracked by space-based sensors in higher orbits.

HBTSS theoretically solves this problem via a proliferated constellation of Overhead Persistent Infrared (OPIR) sensors operating in low earth orbit. At that lower orbit, the sensors will be able to pick up and track the otherwise dim objects. But because the satellites are closer to the earth and have a limited field of view, the system will need to pass off custody responsibility from sensor to sensor as the weapons traverse the globe. Hence the need for a proliferated constellation.

HBTSS will plug into the Space Development Agency’s National Defense Space Architecture, a new system of satellites operating in low earth orbit.

The Missile Defense Agency awarded $20 million contracts to four companies in October to develop HBTSS prototypes: Northrop Grumman, Leidos, Harris Corporation and Raytheon.

The Senate’s version of the National Defense Authorization Act would authorize the Missile Defense Agency $120 million in research, development, testing and engineering funds for HBTSS.

If passed, this would be the second consecutive year the department did not include money for HBTSS in its annual budget request, but Congress allocated money for the project anyway. In 2019, MDA put the program at the top of its unfunded priority list, seeking $108 million for that effort. Congress fully funded that request in the legislation that passed in December.

The decision to give the HBTSS funding to the Missile Defense Agency in fiscal year 2021 continues a 2019 battle between the administration and Congress over which agency should lead the program’s development effort. While lawmakers wanted to place MDA firmly in charge of the effort, the White House argued that it was too soon to put one agency in charge. Ultimately, Congress included a provision putting primary responsibility for the development and deployment of the system in MDA’s hands.

Just three months after that legislation passed, lawmakers expressed frustration and confusion over MDA’s FY2021 budget request, which sought to transfer HBTSS funding responsibility to SDA. While MDA Director Vice Adm. Jon Hill tried to assure legislators at the March hearing that his agency was fully in charge of developing the sensor for HBTSS, skepticism has continued. According to Hill, funding for the effort would be allocated to SDA, who would in turn provide the funding to MDA. As currently drafted, the legislation de facto rejects DoD’s request to transfer funding responsibility to SDA.

Furthermore, it specifically assigns principal responsibility for the development and deployment of HBTSS through the end of FY2022, after which it may be transferred over to the U.S. Space Force.

It’s not the only legislative proposal emphasizing Congress’ desire for MDA to be in charge of the system.

The House version of the FY2021 defense bill made public in June asks for the Secretary of Defense to certify that MDA is indeed in charge of HBTSS. According to a defense official, Under Secretary of Defense for Research and Engineering Michael Griffin sent a letter signed May 29 certifying that MDA was in charge of payload development. Griffin has since resigned, stating that he has received an opportunity to work in the private sector.

The Senate version requires on orbit testing of HBTSS to begin by December 31, 2022, with full operational deployment as soon as technically feasible.

Nathan Strout covers space, unmanned and intelligence systems for C4ISRNET.

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