Moscow, May 11 (IANS/RIA Novosti) Russian space freighter has undocked from the International Space Station Monday to embark on a two-month flight to carry out a geophysical experiment.

The Progress M-04M space freighter had been docked with the ISS since Feb 5 and will now remain in autonomous flight for two months to take part in a geophysical experiment to study the reflective characteristics of the freighter's hull and the transparency of the earth's atmosphere, a mission control spokesperson said.

It will then be "buried" in the Pacific Ocean July 1.

"Progress M-04M has been undocked from the ISS and with the help of its on-board motor will go into a working orbit not far from the station," the spokesperson said.

Progress-series freighters have been the backbone of the Russian space cargo fleet for decades.

In addition to their main mission as cargo spacecraft, they are used to adjust the ISS orbit and conduct scientific experiments.