MDA Decomissions Two Missile-Tracking Satellites After 12 Years of Service

The Missile Defense Agency has decommissioned two Space Tracking and Surveillance System satellites after over 12 years of service. The satellites stopped collecting data in September 2021.

The STSS satellites were created by Northrop Grumman and were launched to low-Earth orbit on a United Launch Alliance Delta 2 rocket in 2009. Their mission was to detect missile launches and track U.S. missile tests from over 1,300 kilometers above the Earth using infrared sensors.

The satellites have been passivated and moved to orbits that were selected to prevent contact with other space objects. The organization requested $15.2 million in its fiscal year 2022 budget for the operation, SpaceNews reported.

The STSS mission was conceived in the 1990s when the Department of Defense planned to deploy a constellation to support missile monitoring tasks performed by the geostationary Space-Based Infrared System satellites. The program, dubbed SBIRS Low, was transferred to the MDA in 2001, where it became the STSS.

MDA said the satellites were originally expected to work for only four years. With the eight additional years of service, the agency was able to use data to develop new missile defense sensors and systems, including the Hypersonic and Ballistic Tracking Space Sensor program.

In 2023, the DOD component will begin an on-orbit demonstration of two HBTSS prototypes made by Northrop Grumman and L3Harris Technologies. Like the STSS, the anticipated satellites will detect and track missile threats from low-Earth orbit and will use infrared sensors to execute their mission.