Original sentence: The unresearched claim that "in space metals stick" requires further qualification.This phenomenon has been replicated using only carefully-designed experiments that limit themselves to susceptible materials, taking great care to avoid contamination, and requiring mechanical removal of oxide layers
Edited sentence: However, in 2006, Henry Spencer stated that the phenomenon of spontaneous cold welding in outer space is "basically a myth", pointing out that "there are no documented cases of it actually occurring in orbit, except in experiments deliberately designed to provoke it (with susceptible materials, great care to avoid contamination, and deliberate mechanical removal of oxide layers, etc