After nearly two weeks of delays, a rocket holding NASA's second Mars rover was launched into a night sky Monday on a mission to study whether the Red Planet ever had enough water to sustain life.
The rover, Opportunity, lifted off in a cloud of steam aboard a Delta II Heavy rocket at 11:18 p.m. NASA Administrator Sean O'Keefe flew to the Cape Canaveral Air Force Station to watch the launch.
The launch had been postponed more than a half-dozen times because of bad weather, a failed battery cell and a problem with cork insulation failing to stick to the aluminum rocket.
Technical problems continued to plague the launch Monday night. Launch officials halted the countdown with seven seconds left during the first launch opportunity at 10:35 p.m. because of a problem with a rocket valve.
NASA had until July 15 to launch Opportunity before Earth and Mars became too far apart. The next chance would be in four years.
The failed battery cell was discovered over the weekend and replaced. Fixing the cork on the Delta II Heavy rocket had been more challenging. The cork is believed to have peeled off from the rocket during fueling, when minus-300-degree liquid oxygen is loaded into the rocket. Workers replaced pieces of the cork and used a stronger adhesive.
Workers also fixed minor last-minute problems Monday night on software and the replacement battery cell.
Opportunity and its sister rover, Spirit, which was launched last month, are scheduled to arrive at Mars in January and land on opposite sides of the planet as part of the $800-million mission.