USA-273, also known as SBIRS GEO-3, is a United States military satellite and part of the Space-Based Infrared System (SBIRS).
Launch of USA-273 on an Atlas V
SBIRS GEO-3 in orbit
Space-Based Infrared System
The Space-Based Infrared System (SBIRS) is a United States Space Force system intended to meet the United States' Department of Defense infrared space surveillance needs through the first two to three decades of the 21st century. The SBIRS program is designed to provide key capabilities in the areas of missile warning, missile defense, battlespace characterization and technical intelligence via satellites in geosynchronous Earth orbit (GEO), sensors hosted on satellites in highly elliptical orbit (HEO), and ground-based data processing and control.
SBIRS High GEO
SBIRS Low