Abstract: Welding in space can grow to be a helpful method e.g.for repairing solar electric panels.A welding process was obtained for the spot welding by water(or other liquids) jet impact.The process offers ring-zone like welded areas with high strength.A system was found,which is able to produce the high speed liquid-jets and it can be built with small dimensions.This together give the idea and possibility of the welding of thin sheet plates in space by liquid jet impact.