Welding In Space: An Insight Into Cold Welding

Let’s start with a simple science lesson: because there is no oxygen in space, creating sparks and lighting a fire is extremely difficult. Now for welding, sparks and fire are pretty essential. So what happens when repairs are needed 60-odd miles up in the air?

This was one of the main issues that was presented to astrophysicists in the early ages of space travel. Thankfully for the future of space travel and research, over a number of years, a solution was created: cold welding.

By forming metals and materials together without any liquid or molten phase, astronauts are able to work quickly and efficiently outside of their spacecraft. Instead, cold welding consists of bonding two surfaces together through atomic diffusion. This is when the molecules of both surfaces are thermally activated and the movement created by this process allows the surfaces to bind together.

“But how can it be called cold welding if the molecules are being thermally activated.” Well, when we say cold welding, we actually mean ‘just not as hot as regular welding.’ The whole premise of cold welding is to control the temperature so that it does not exceed a certain limit that would put an astronaut in danger.

The whole process is relatively complex, and with complexity comes vulnerability. In the earliest stages of research and experiment into cold welding, there were a number of doubts. The strength and effectiveness of this practice had been cast into doubt, particularly after an incident in 1991 with the Galileo spacecraft which was cited by the European Space Agency.

With alternative solutions few and far between, the option of developing and fine-tuning the technology of cold welding seemed to be the only viable option.

Over the next 20 years, scientists tackled this issue head on and we are now left with the variable power handheld laser torch tool. This torch is specifically designed to weld materials together through the aforementioned process of atomic diffusion as safely as possible. By reducing the radius of heat that is omitted and with a number of sensors, the torch is far more accurate than those used in 1991 and significantly safer.

The technology has now become so advanced that it has left the clutches of NASA and has now entered the commercial world. Although traditional welding is the method of choice in the lower end of the industry, with the development into cold welding ever increasing, the possibility of it replacing the age-old process is very real.

As space failed to accommodate for the industry of traditional welding, the development of cold welding has allowed the research into our atmosphere to accelerate our knowledge of the galaxy. To infinity and beyond!