A 1961 Soviet space capsule that carried a cosmonaut mannequin and a live dog into space was sold at Sotheby's for 2.9 million dollars (£1.8 million), a spokesman for the New York auction house said.
The buyer of the Vostok 3KA-2 was Russian businessman Evgeny Yurchenko, said David Redden, of Sotheby's. The total price included the buyer's premium.
Mr Redden said Mr Yurchenko planned to take the capsule back to his home country.
"I hope that Vostok will take its rightful place in one of the nation's museums devoted to the history of the formation of the Russian space programme," Mr Yurchenko said in a statement issued by Sotheby's.
The capsule, made of aluminium alloy and measuring just over 7ft in diameter, was used on a test run for the spacecraft that carried the first man into outer space. Its pre-sale estimate was two million dollars -10 million dollars and it was offered on the 50th anniversary of the manned mission. It was classified "secret" until 1986.
Though it was scorched during its re-entry into the Earth's atmosphere, it brought a dog named Zvezdochka, or Little Star, safely back from space. The life-size space-suited mannequin was nicknamed Ivan Ivanovich.
Sotheby's said the anonymous seller bought it privately from the Russians years ago.
The capsule went into space weeks before the manned flight of Vostok 3KA-3, which carried cosmonaut Yuri Gagarin.
Redden said that getting the Vostok 3KA-2 back to Russia might be complicated because it is classified by the US State Department as a space object. "Interestingly enough, it requires some special licences," he said.