This story was updated at 2:40 a.m. ET.
The U.S. Air Force lit up the night sky above California Saturday (Sept. 25) with the launch a new satellite sentinel to keep tabs on other spacecraft and the growing problem of space junk around Earth.
The Space-Based Space Surveillance satellite, called SBSS, will monitor the orbital environment as part of the U.S. military's evolving Space Surveillance Network.
The satellite blasted off from Vandenberg Air Force Base atop a Minotaur 4 rocket at 9:41 p.m. PDT (0441 GMT). Air Force officials said the rocket reached its intended orbit and deployed the SBSS spacecraft as planned. [ Photo of the satellite's night launch.]
"This satellite is going to revolutionize the way we track objects in space by not being constrained by weather, the atmosphere or the time of day," said Col. J.R. Jordan, vice-commander of the Space Superiority Systems Wing at the U.S. Air Force Space and Missile Systems Center, in a prelaunch briefing. "This capability will be essential to our space situational awareness architecture for the near future and beyond." [ Worst Space Debris Moments in History ]
The satellite is essential to keep U.S. space assets safer and more secure, as well as "keeping America at the forefront of space," Jordan added.
The overall cost of the SBSS program is about $858 million, Air Force officials have said.
There are about 500,000 known pieces of space junk orbiting around our planet. Of those, about 21,000 objects are larger than 4 inches (10.1 cm) in diameter, and are being tracked by the Department of Defense, as part of the Space Surveillance Network. These are items like spent rocket stages and broken satellites.
The 2,277-pound (1,031-kg) SBSS satellite was launched on a Minotaur 4 rocket, which was designed by the Virginia-based Orbital Sciences Corp. It was the first time a Minotaur 4 booster has been used to launch a satellite into space.
The Minotaur 4 rocket is a four-stage booster with three stages built using retired Peacekeeper missile motors and a commercial fourth stage developed by Orbital Sciences. The rocket can launch payloads weighing nearly 2 tons into orbit. It made its first test flight in April.
The SBSS satellite is about the size of a small car, Air Force officials said. It is designed to track space debris and satellites from an orbit about 392 miles (630 km) above Earth.
"SBSS will greatly enhance our existing space situational awareness capability, a capability vital to protecting our space-based assets," said Col. Richard Boltz, commander of the 30th Space Wing at Vandenberg Air Force Base. Boltz added that Saturday night's launch was the third in eight days for Vandenberg's launch team.
Aerospace heavyweight Boeing is responsible for the overall SBSS program management. The Colorado-based Ball Aerospace & Technologies Corp. developed, designed, manufactured and tested the satellite, using the Boeing-built onboard mission data processor.
The spacecraft is equipped with a visible sensor mounted on an agile, two-axis gimbal. This device will give ground controllers the flexibility to quickly move the camera between targets without needing to reposition the satellite itself or expend additional fuel.
"That gimbal is able to quickly move to detect events in space," said Todd Citron, director of the Boeing Advanced Space and Intelligence Systems. "The agility contributes significantly to the advantages of the SBSS to provide space situational awareness."
The satellite will collect data to be used in conjunction with observations from ground-based radars and telescopes.
The SBSS satellite was originally scheduled to launch in Oct. 2009 but was delayed due to technical concerns with its rocket launch vehicle.
Saturday's liftoff was the second of three Minotaur 4 rocket launches planned for this year. The next flight is slated to launch Nov. 19 carrying several satellites for the Air Force's Space Test Program.