Today’s satellites are intricate, multifaceted creations, and they continue to include vital hand-made components. To ensure the electronic hardware for space missions that’s made with a human touch adheres to stringent standards, a series of ESA-approved schools train and certify top solderers.
“Soldering is an essential skill to assemble devices onto printed circuit boards (PCBs),” according to the ESA, and they are “the source of their host machine’s capabilities and intelligence.”
One satellite could contain numerous PCBs, and unlike other technology like smartphones, satellites must continue functioning for multiple years in space without failure.
“It’s a different scenario from mass-produced terrestrial PCBs, where a badly soldered board or an assembly that does not function as it should can just be thrown away. A single custom-made PCB might be worth tens of thousands of Euros and maybe have taken a year to make, so the onus is on operators and inspectors to modify the assembly—bearing in mind at the same time that too much reworking can also reduce an assembly’s lifetime reliability,” Soldering Instructor Brett Smith of ASTA Technology, explains.
Since soldering work for space missions differs from soldering for terrestrial applications, the process is much more rigorous.
“It takes place inside an environmentally controlled cleanroom—the particle count permitted within it depends on the sensitivity of the products being assembled. You wear an electrostatic discharge bracelet and other ‘ESD’ safe clothing, gloves, hair nets and in some cases beard guards—preventing static and debris from your own body doing damage or contaminating the equipment,” Smith says.
Flight hardware must be kept away from paper instructions, since microscopic fibers are damaging contaminants. Smith continues to say that since this is high-level precision work, solderers use a microscope ranging from four to 40 times magnification.
Thomas Rohr, heading ESA’s Materials and Processes section, explains why so much caution is used for soldering for space applications, “There is the violent vibration of launch, mechanical shock of launcher separation followed by the weightlessness, vacuum, and temperature extremes of Earth’s orbit—space is a place where it is possible to be hot and cold at the same time. Plus there is the dimension of time: our missions must go on operating reliably for years on end. We have to engineer accordingly.”
The electronics industry is more reliant on machine-based soldering, according to the ESA, but human soldering is still needed for production needs and precision fixes. According to the agency, “the human hand and eye are still superior to machinery.”
More than a thousand individuals enroll in the soldering schools located all across Europe, and other countries such as Argentina, Malaysia, and the U.S.