A US satellite to monitor global carbon dioxide emissions plummeted into the ocean near Antarctica Tuesday after failing to reach orbit, NASA officials said, calling it a major disappointment for climate science.

NASA said the satellite launched successfully from the Vandenberg Air Force Base in California aboard a Taurus XL rocket at 1:55 am (0951 GMT).

A fatal mission error occurred minutes after liftoff when a clamshell-like fairing that protects the satellite during its ascent failed to separate properly.

"The initial indications show that the vehicle did not have enough lift to reach orbit and landed short of Antartica in the ocean," said John Brunschwyler, program director for the Taurus rocket at Orbital Sciences Corporation, the Virginia-based company that built it.

"Our whole team at a very personal level are disappointed, we are very upset with the results," he added.

It was the first time NASA had used a Taurus rocket, but Brunschwyler said the system has had a nearly perfect record in 56 previous flights with no issues with the fairing design.

"The liftoff was smooth," Jet Propulsion Laboratory spokesman Alan Buis told AFP.

"It was pretty far along in the ascent" over the Pacific Ocean when the "contingency" was declared, Buis said.

The mission of the Orbiting Carbon Observatory (OCO) was to map the global distribution of carbon dioxide and study how it changes over time, NASA said in a statement.

Carbon dioxide is the leading greenhouse gas driving climate change.

Other than the verbal commentary during the launch there was little visual indication on NASA TV that the satellite had failed.

"Several minutes into the flight, launch managers declared a contingency when the fairing failed to separate properly," NASA said in a brief statement.

NASA flight director Chuck Dovale said all indications were that all stages of the launch vehicle burned, so there was no threat to the environment from the toxic hydrazine fuel on board.

An investigation board would be formed to determine the "probable cause" of the failure, he said.

He called it "a huge disappointment" for the science community.

Michael Freilich, the director of NASA's science division, said it was unclear how long it might take to field a replacement for the OCO, which took eight years to develop.

It was NASA's first spacecraft dedicated to studying carbon dioxide, though not the first in orbit: on January 23 Japan launched the world's first satellite dedicated to monitoring greenhouse gas emissions.

"The science is moving forward so it's difficult to put a precise time delay on how quickly in the future we would be able to realize the understanding that OCO would have given us, having succeeded," Freilich said.

The Japanese mission will help scientists measure the density of carbon dioxide and methane from almost the entire surface of the Earth, the Japan Aerospace Exploration Agency (JAXA) said.

A Japanese-made H-2A rocket carrying the Greenhouse Gases Observing Satellite (GOSAT) blasted off from Tanegashima, a small island in southern Japan.

The satellite is collecting data from 56,000 locations around the world, a dramatic increase from the 282 observation points available as of last October, JAXA said.

Japan hopes the mission will provide governments with useful data as they come under pressure to meet their 2008-2012 Kyoto Protocol goal of cutting greenhouse gas emissions.