Welding Tests By Cosmonauts

Press, Volume CIX, Issue 32120, 16 October 1969, Page 1

Welding Tests By Cosmonauts

(N.Z.P.A.-Reuter—Copyright) MOSCOW, October 15. The official Soviet Union news agency, Tass, said today that two of the seven cosmonauts now orbiting the earth in three Soyuz spacecraft would be engaged in welding experiments connected with the building of future space laboratories.

The announcement came in I an article by the news! agency's science correspondent soon after the first official mention of the Russian aim of building orbiting labora-

tories. The welding experiments, in conditions of high vacuum 1 and weightlessness, would be done by the crew of Soyuz 6, Lieutenant - Colonel Georgy Shonin, the commander, and Dr Valery Kubasov, the civilian flight-engineer, the correspondent said.

An explanatory statement on the group flight was made in Wellington today by the First Secretary (Press) at the Russian Legation (Mr E. Podzniakov). “Experiments in space will reveal new opportunities for developing cold-welding techniques, or, more precisely, studying the method known as diffusion welding in a vacuum,” he said. “This type of welding does not accord with the classical definition, but, with much smaller power requirements, it provides for the reliable

I fusion of aluminium and its | alloys, copper, nickel, lead, I zinc, silver and gold.. “Diffusion welding also provides a method of uniting such combinations as steel

and glass, or silver and quartz. However, the two surfaces have to be only several 'millionths of a millimetre apart, and they have to be free of the slightest grease film and oxidised film. . It is here that the vacuum technology assists, by removing the oxygen. The higher the vacuum, the better the welded joint. “An almost absolute vacuum exists in space. At a height of 125 miles, the density of the earth’s atmosphere is 1000 million times less than at sea level. This is a much higher vacuum than has been achieved in the laboratory on earth. “. . . Diffusion welding is going to be important in the construction of large orbiting space stations in the future, and an additional advantage here will be thermal energy, where required, provided by the sun.”