Hypersonic and Ballistic Tracking Space Sensor

The Hypersonic Ballistic Tracking Space Sensor (HBTSS) is a satellite-based sensor system being developed by the Missile Defense Agency (MDA) along with the Glide Phase Interceptor (GPI) to address hypersonic threats. The product of the 2019 Missile Defense Review's (MDR) for further enhancement of the US national missile defense system, the HBTSS will provide quality intercept data to the GPI. Equipped with "Birth-to-death" capability, the HBTSS can track potential threats from their launch until interception. The HBTSS will ultimately be integrated into the broader set of satellite constellations being developed by the Space Development Agency (SDA).

The new satellite architecture itself, dubbed the Proliferated Warfighter Space Architecture (PWSA), will consist of seven layers: data tracking, transport, custody, battle management, navigation, deterrence, and support. The HBTSS will be a part of the tracking layer, whose goal is to "provide global indications, warning, tracking, and targeting of advanced missile threats, including hypersonic missile systems." It will work alongside SDA-developed Wide Field of View (WFoV) satellites with its Medium Field of View (MFoV) with the WFoVs cueing data to the HBTSS which will then provide more specific and quality target data, referred to as "fire control data," to linked ground-based interceptors. This combination of both MFoVs and WFoVs are crucial as normal radars may miss fast-moving advanced missile technologies such as the Russian-made Avangard and Chinese-made Starry Sky-2, which are Hypersonic Glide Vehicles (HGVs).

The current phase of the HBTSS program is in protype stage and lacks operational capability. The HBTSS program plans to launch two demonstration sensors into orbit by Fiscal Year (FY) 2023. The Missile Defense Agency have selected two military contractors - L3Harris Technologies and Northrop Grumman - to design, build, and lastly demonstrate prototype satellites for the HBTSS in January 2021. Both were awarded with contracts worth hundreds of millions of dollars. By December 2021, these prototype satellites had passed critical design reviews, meaning manufacturing can move forward.

On February 2024, the Department of Defense (DOD) announced the successful launch and trajectory insertion of six satellites, which include two prototypes of the HBTSS.