It looks like the rocket carrying an Earth-observation satellite has fallen into the Pacific Ocean after a failed launch attempt early Friday, NASA said.
The Taurus XL rocket carrying NASA's Glory satellite lifted off around 2:10 a.m. PST (10:10 a.m. GMT) from Vandenberg Air Force Base in California.
But NASA said in a brief statement that a protective shell or fairing atop the rocket did not separate from the satellite as it should have about three minutes after the launch.
That left the Glory spacecraft without the velocity to reach orbit, NASA launch commentator George Diller said.
"The flight was going well until the time of fairing separation," Diller said. "We did not have a successful fairing separation from the Taurus and there was insufficient velocity with the fairing still on for the vehicle to achieve orbit."
Glory was launched on a three-year mission to analyze how airborne particles affect Earth's climate. Besides monitoring particles in the atmosphere, it will also track solar radiation to determine the sun's effect on climate change.
The $424 million mission is managed by the NASA's Goddard Space Flight Center in Maryland.
Friday's launch came after engineers spent more than a week troubleshooting a glitch that led to a last-minute scrub.
Glory was supposed to study tiny atmospheric particles known as aerosols, which reflect and trap sunlight. The vast majority occurs naturally, spewed into the atmosphere by volcanoes, forest fires and desert storms. Aerosols can also come from manmade sources such as the burning of fossil fuel.
NASA suffered a mishap two years ago when a global warming satellite also destined to join the Earth-observation network crashed into the ocean near Antarctica after launching from the same kind of rocket that carried Glory. An accident board was formed to investigate and corrective action was taken to prevent future problems. A duplicate is now scheduled to fly from Vandenberg in 2013.