A Delta IV-Heavy rocket roars off a launch pad at Cape Canaveral, on Nov. 10, 2007, carrying the 23rd Defense Support Program satellite. This payload marks the end of an era, as it is the final DSP satellite in its program.

DSP satellites have provided early warning for intercontinental ballistic missile launches since 1970. The satellites employ infrared sensors for detection of heat from missile and booster plumes against the Earth's background.

This latest arrival, with previous DSP satellites, will continue to provide national defense support as part of the Space-Based Infrared System constellation. DSP will make up part of a blended constellation including the SBIRS highly elliptical orbit and geosynchronous orbit satellites.

The launch also marked the first time a Delta IV-Heavy rocket was used for the purpose of placing an operational satellite into orbit. The Delta 1V-Heavy (full name: Delta IV-Heavy Evolved Expendable Launch Vehicle) represents the United States' largest and most powerful unmanned booster rocket. This spacefaring behemoth stands more than 230 feet tall, and unleashes nearly two million pounds of thrust from its three hydrogen-fueled main engines.

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-U.S. Air Force Space Command and SPACE.com Staff

Credit: Carleton Bailie/United Launch Alliance