Why is it always a helium leak? It seems whenever there’s a scrubbed launch or a narrowly averted disaster, space exploration just can’t get past the problems of helium plumbing. We’ve had a bunch of helium problems lately, most famously with the leaks in Starliner’s thruster system that have prevented astronauts Butch Wilmore and Suni Williams from returning to Earth in the spacecraft, leaving them on an extended mission to the ISS. Ironically, the launch itself was troubled by a helium leak before the rocket ever left the ground. More recently, the Polaris Dawn mission, which is supposed to feature the first spacewalk by a private crew, was scrubbed by SpaceX due to a helium leak on the launch tower. And to round out the helium woes, we now have news that the Peregrine mission, which was supposed to carry the first commercial lander to the lunar surface but instead ended up burning up in the atmosphere and crashing into the Pacific, failed due to — you guessed it — a helium leak.
Thankfully, there’s a bit more technical detail on that last one; it seems that a helium pressure control valve, designated PCV2 and controlling helium to pressurize an oxidizer tank, got stuck open thanks to “vibration-induced relaxation” in threaded components within the valve. So, launch vibrations shook a screw loose inside the valve, which kept it from sealing and over-pressurized an oxidizer tank with helium to the point of tank failure — kablooie, end of mission. All of these failures are just another way of sayin ..
Support the originator by clicking the read the rest link below.
