Bangalore, Sep 23 - India Wednesday successfully injected a cluster of six European micro-satellites into low-earth orbit after deploying its 960 kg remote sensing satellite Oceansat-2 in the polar sun-synchronous orbit.

This is the second time India's space agency launched multiple satellites - it deployed on the polar orbit a record 10 satellites, including eight international nano-satellites, on April 28, 2008.

Of the six micro-satellites, which had a piggy ride on Oceansat-2, four are from Germany and one each from Switzerland and Turkey, with a combined weight of 20 kg.

The first four tiny spacecraft, christened Cubsats, are educational satellites from European universities weighing around one kg and developed to perform technology demonstration in space.

The other two spacecrafts are christened Rubin-9.1 and Rubin-9.2.

'The satellites were launched inside a single pico-satellite launcher, also weighing one kg,' the Indian Space Research Organisation (ISRO) said in a statement after the seven satellites were launched onboard the 320-tonne polar launch satellite vehicle (PSLV-C14) from spaceport Sriharikota, about 80 km northeast of Chennai.

Cubesat-1 from University Wurzburg in Germany is a pico-satellite. Its mission objective is to demonstrate a newly developed attitude determination and control system and how a global positioning system (GPS) functions in a tiny spacecraft.

Cubesat-2 or BeeSat from Technical University of Berlin in Germany is also a pico-satellite. Its objective is to verify the on-orbit function of newly developed micro reaction wheels for pico-satellite applications.

It will demonstrate the use of coin-sized micro reaction wheels for attitude control of pico-satellites in orbit as one of the key elements.