Eight repair workers at Russia's main space launch facility in Kazakhstan are feared dead after the roof of a hangar collapsed on Sunday.

Russian space officials say the eight repair workers were on the roof when it suddenly collapsed, and it's unlikely they survived the 80 meter fall to the ground.

The roof fell when three support columns gave way at a large hangar which has long been used to test space vehicles.

The hangar is one of many buildings at the Baikonur Cosmodrome, which has served for decades as the main Russian base for space launches.

A specialized rescue team has been sent from Moscow to the space complex, located out on the vast plains of Kazakhstan.

Space agency officials say that only well-trained experts can enter the partially collapsed building. High winds have also hindered any attempt to rescue the men buried under the rubble.

The hangar was primarily used for the Russian space shuttle known as the Buran, which was discontinued due to lack of funds in the early 1990's.

Russia's space program has long been hindered by reduced state funding since the end of the Soviet Union, and many facilities are in need of repair.

In the past year Russia has turned to space tourism to partly make up for the financial shortfall; an American and, just two weeks ago, a South African have both paid around 20-million dollars to go to the International Space Station.

Both were launched into space from Baikonur, which was also the launch site for the first man in space, Yuri Gagarin, in 1961.