An Atlas V rocket operated by the United Launch Alliance on mission AV-076 put the SBIRS GEO-4 early warning/missile warning satellite on behalf of the US Air Force into orbit on 20 January 2018. The Atlas V 411 rocket lifted off at 0048 GMT from its launch pad at Cape Canaveral, Florida. The 4,833 kg satellite which uses Lockheed Martin’s A2100M (SBIRS) bus design was sent into a transfer orbit from which it will use its own engine to circularise itself into a slightly inclined geosynchronous orbit.

Atlas V launches SBIRS GEO-4 Courtesy: ULA

The Space Based Infra Red System (SBIRS) has had four satellites launch to date.  Two more are due to complete the programme.

After the launch, the Centaur stage of the rocket made an additional burn to lower its perigee and thus remove itself from orbit. It re-entered at 1013 GMT over the Pacific, South West of Hawaii (detail courtesy Jonathan McDowell).