An official website of the United States government
Here's how you know
A .mil website belongs to an official U.S. Department of Defense organization in the United States.
A lock (lock ) or https:// means you’ve safely connected to the .mil website. Share sensitive information only on official, secure websites.

HomeAbout UsFact Sheets

Fact Sheet Search

Fact Sheet Alphabetical List

Space Based Space Surveillance


The Space Based Space Surveillance (SBSS) operates 24-hours a day, 7-days a week collecting metric and Space Object Identification data for man-made orbiting objects without the disruption of weather, time of day and atmosphere that can limit ground-based systems. SBSS has a clear and unobstructed view of resident space objects orbiting earth from its 390-mile altitude orbit.

SBSS communicates information through the world-wide Air Force Satellite Control Network and commercial Unified Space Network ground stations and then to Schriever Air Force Base, Colo., where operators oversee the day-to-day command and control operations of SBSS. This satellite system can monitor very small objects all the way out to the Geosynchronous belt. SBSS provides the data necessary to predict the trajectories of these objects, which gives experts an idea if an orbiting satellite may collide with another orbiting object, which allows time for evasive action to be taken in order to avoid collisions.


SBSS was launched from Vandenberg AFB, Calif., Sept. 25, 2010. The first signals from the space surveillance satellite were received a short time later at the Satellite Operations Center at Schriever AFB. U.S. Air Force Space Command declared that the SBSS satellite reached Initial Operating Capability on Aug. 17, 2012.

SBSS is the follow-on to the Midcourse Space Experiment (MSX) satellite, which was the first space-based sensor to contribute to the Space Surveillance Network after initially being a technology demonstration to identify and track ballistic missiles during their midcourse flight phase.


SBSS uses a visible sensor mounted on an agile, two-axis gimbal, which allows ground operators to quickly move the camera between targets without having to expend time and fuel to reposition the entire spacecraft.

General Characteristics

Primary Mission: Space Surveillance
Orbit Altitude: Sun Synchronous
Dimensions: Solar Panels - 201.36 inches x 92.50 inches
Length Along Z-Axis: 110.33 inches
Weight: 1,031 kilograms (2277 pounds)

(Current as of July 2019)