The SBIRS satellites fly in geostationary orbits, and are equipped with powerful scanning and staring infrared surveillance sensors that collect data for use by the US military to detect missile launches, support ballistic missile defense and gather broader intelligence. This event took place hours before the federal government was in danger of being shut down due to budget problems. ULA's Atlas V rocket is scheduled to blast-off at 7:48 p.m. ET from Space Launch Complex-41 at Florida's Cape Canaveral Air Force Station.
The U.S. Air Force is set to launch a new missile-warning satellite into space on Thursday night. It's also the 75th Atlas V launch since the rocket's inaugural flight in 2002.
On its 75th flight Atlas V will launch the fourth geostationary satellite in the Space Based Infrared System (SBIRS), which is a group of satellites created to detect and track missile launches on Earth. The SBIRS program is created to act as a missile-warning system and provide technical intelligence.
About 42 minutes after liftoff, the satellite is expected to reach an initial orbit that ranges from 100 miles (161 kilometers) at its closest point to Earth to 19,358 miles (31,154 km) at its farthest point, according to a ULA mission description.
NASA Spaceflight said: "These include the first Atlas V launch with a dual-engine Centaur and no payload fairing - the N22 configuration - which will be used to deploy Boeing's Starliner spacecraft".