An auction of valuable Soviet space memorabilia has been cancelled in New York after Sotheby’s was unable to attract serious buyers. The move dashes hopes that rare documents relating to the golden age of space exploration might be returned to Russia.

Observers say the credit crunch has dampened the market.

Among the relics for sale was a report made by the first man in Space, Yury Gagarin, during his historic flight on April 12, 1961. The document – one of only four copies made, features the first-ever description of Earth from orbit, and had a price-tag of $US 700,000.

Also up for grabs was Gagarin's speech, given to Soviet space experts just two days before he went into space. This lot was expected to go for at least $US 200,000.

Other documents on display were diaries of space constructor Vasily Mishin, an aid to the founding father of Soviet space programme Sergey Korolyov.

The relics, first auctioned at Sotheby's fifteen years ago, were bought by American billionaire and politician Ross Perot.