Riding piggyback on the 970 kg Oceansat-2, six other nano satellites -- four from Germany and one each from Switzerland and Turkey -- would be ejected into space by Indian Space Research Organisation (ISRO)'s workhorse PSLV, which launched India's Chandrayaan-1 spacecraft on its maiden moon mission.

The final 51-hour countdown for the launch began at 9 am on Monday and has been "progressing normally", ISRO spokesperson S Satish said.

"All parameters are normal and efforts are on for a smooth launch," he said, adding the weather was absolutely fine for the launch.

The launch window for the lift off from the Satish Dhawan Space Centre at Sriharikota in Andhra Pradesh is fixed between 11.51 am and 12.06 pm.

Oceansat-2, India's 16th remote sensing satellite, is intended for identification of potential fishing zones, sea state forecasting, coastal zone studies and providing inputs for weather forecasting and climate studies.

An in-orbit replacement to Oceansat-1, used to study physical and biological aspects of oceanography, which has completed 10 years of its space journey, Oceansat-2 would have a mission life of five years.

Besides two German Rubin nano satellites, other Oceansat-2 co-passengers are four cubesats: Beesat, built by Technical University Berlin, UWE-2 (University of Wuerzburg Germany), ITU-pSat(Istanbul Technical University Turkey) and SwissCube-1 (Ecole Polytechnique Federal de Lausanne, Switzerland).

The nano satellites are in the two-eight kg range. Oceansat-2 and the six auxillary payload would be ejected into a polar Sun Synchronous Orbit, ISRO officials said.
The nano satellites are educational spacecrafts from European Universities intended for testing new technologies.

Oceansat-2 would be injected into space first and the remaining one after another, officials said. The eight band Ocean Colour Monitor carried by Oceansat-2 images a swath (strip of land or ocean) of 1,420km with a resolution of 360 metre and works in the visible and Near infrared region of the electromagnetic spectrum. The Scatterometer covers a swath of 1,400 km and operates continuously.

In April 2008, ISRO had launched 10 satellites in a single mission --one big spacecraft (Cartosat-2A) and nine nano satellites. PSLV-C14 during its path, has four stages using solid and liquid propulsion systems alternately. The first stage, carrying 139 tonne of propellant, is one of the largest solid propellant boosters in the world while the second stage carries 41.5 tonne of liquid propellant. In the third the satellite uses 7.6 tonne of solid propellant and the fourth has a twin engine configuration with 2.5 tonne of liquid propellant.