刚刚！美国成功发射一颗新型天基红外弹道导弹预警卫星 ncaa2018-01-20 03:09:32
United Launch Alliance’s Atlas V has launched on her seventy-fifth flight, lofting the SBIRS GEO-4, a missile early warning satellite. Following a scrub on Thursday, Friday’s attempt was issue free, launching at the opening of the window at 19:48 Eastern time (00:48 UTC on Saturday).
SBIRS GEO-4 is the fourth geostationary satellite in the Space Based Infrared System (SBIRS), a constellation of satellites that use infrared sensors to detect and track missile launches.
Replacing the Defense Support Program (DSP), a fleet of satellites that began watching for missile launches in the 1960s, SBIRS is designed to provide the United States with advance warning of an enemy nuclear strike, while also allowing the country to monitor other missile and rocket launches around the world.
In addition to its geostationary satellites, SBIRS also uses sensors mounted aboard satellites in highly elliptical orbit (HEO). Piggybacked on the National Reconnaissance Office’s Trumpet-class signals intelligence satellites, these SBIRS-HEO sensors provide additional observations of Earth’s polar regions, which are less visible from geostationary orbit.
SBIRS – via Lockheed Martin