The last Atlas 2 rocket was launched on Tuesday, putting a national security satellite into orbit after four days of delays caused mostly by stormy weather.
The two-stage rocket, built by Lockheed Martin and launched by International Launch Services, jumped off Launch Pad 36A at the Cape Canaveral Air Force Station at 7:17 p.m. ET after a 28-minute delay for adjustments to a valve on the first-stage booster.
On Saturday, a wrongly set valve caused one of the four days of delays by accidentally dumping thousands of gallons of super-cold liquid oxygen, one of two fuels used, off the rocket.
The rocket's secret payload belonged to the National Reconnaissance Office, which operates the U.S. network of orbiting spy satellites.
This was the 63rd and final launch of the Atlas 2, which made its debut in 1991 and had a perfect flight record, Lockheed Martin said.
It was also the end of an era dating back to the 1950s, when most rockets, including early manned flights, were launched from concrete blockhouses adjacent to the pads. For this launch, the 120-member team was inside a blockhouse 1,400 feet (427 meters) from the launch pad.
The Atlas 2 is giving way to the Atlas 5, a more versatile and less expensive rocket that is in contention with the new Boeing Delta 4 and other systems to become the primary launch vehicle for NASA's new moon program, which is scheduled to fly in the next decade.
