Inspecting suspected gas leaks on the International Space Station is, of course, a unique endeavor. The constant balancing act between individual safety and the well-being of the entire vessel places a strain on maintenance and operations personnel and emphasizes the reliability of the key technology and specialized equipment.
Recently, this dynamic was illustrated when those onboard the ISS identified a small leak in the ammonia coolant loop. More information about the nature of the leak was needed, but that would entail a risky spacewalk outside the station by an astronaut.
The solution was to employ the Robotic External Leak Locator (RELL), to "smell" for the leak. The RELL's instruments are capable of detecting the amount and types of gases present in assessing leaks or taking samples of the atmosphere outside of the ISS. These samples provide data on the gases which are usually present and therefore establish a baseline to compare against when assessing possible leaks.
A faulty isolation valvewas identified as the source of the leakusing this robotic technology. The information gathered by the RELL helped determine that the leak posed no immediate risk to the station or crew. Later, armed with a pinpoint location and more overall information provided by the RELL, ISS personnel were able to execute a highly-organized spacewalk focused onventing, isolating, and repairing the leaking line.
Since initially coming onto the station in 2015, the RELL has logged nearly 190 total hours in space. The same technology could also find greater application in the industrial chemical and gas sector in helping to ensure greater worker safety.
