Moscow  - Russia successfully sent into orbit Tuesday one of the European Space Agency's (ESA) most advanced missions to date that aims to map the Earth's gravity field, the Russian Space Forces said.

Spokesman Lieutenant-Colonel Alexei Zolotukhin was quoted by Russian news agencies as saying the satellite took off on the back of modified Russian ballistic missile at 1421 GMT from the Plesetsk Cosmodrome in north-west Russia.

"Approximately 1.5 hours after its start, the satellite will already be on its second lap around the Earth," Zolotukhin told Interfax.

The launch was scrubbed just seven seconds before blastoff Monday after the pad holding the rocket failed to clear away.

The launch of the 450 million-dollar the satellite known as Gravity field and steady-state Ocean Circulation Explorer (GOCE) has been pushed back several times over fears that the launch system was not ready after another ESA satellite, meant to map the world's ice fields, crashed in 2005.

GOCE aims to measure the tug and pull of the earth's gravity on the world's oceans and peaks.

The European satellite was years in planning and design to shape a satellite frame that could withstand trying atmospheric conditions at its unusually low orbit, skimming just 260 kilometres above the earth.

At that altitude buffets of air streams are still present in the atmosphere.

Gravity's pull is radically different at the earth's poles than at the equator, and ESA's scientists hope to map these miniscule gravitational variations through two six-month test periods.

They say the data could help understand the tides and currents of the oceans, revolutionize the way altitude is measured, and aid in predicting climate change, volcanic eruptions and earthquakes.