Some detailed information from a Jul 11 2024 article in Science: Given that the parts were ordered from Infineon for spec, and were demonstrated failing the spec (and they didn't then notify...
“We’re seeing some MOSFETs fail at lower radiation levels,” said Shannon Fitzpatrick, associate director of planetary science flight programs, speaking on 9 July to NASA’s Planetary Science Advisory Committee (PSAC). “There is a risk these MOSFET transistors may not meet the radiation tolerance we require.”
Some years ago, Infineon changed its manufacturing process for its radiation-hard MOSFETs, which it designs to meet U.S. military specifications—the same radiation-resistance standards used by the Clipper team. After this change, the company’s classified customers found that several lots of the transistors failed at lower than expected radiation levels, Fitzpatrick said. The company has already corrected the mistake, but Infineon did not report the flaw to NASA because the company did not know what the transistors would be used for, Fitzpatrick said. “They did not realize it was going to affect us.” Infineon did not respond to a request for comment.
The transistors cannot simply be replaced. Clipper’s aluminum-zinc electronics vault, meant to provide a measure of radiation resistance, was sealed in October 2023. Barring an indication that the faulty MOSFETs will cause catastrophic failure, the agency will likely seek to continue with the launch—although backup windows are available the next 2 years.
NASA engineers, working closely with Infineon, are now studying how many of the defective transistors are onboard Clipper, where in the hardware they are deployed, and which ones would most threaten the mission if they failed. They are also looking at possible ways to mitigate the problem, such as turning off certain switches for parts of the spacecraft’s lifetime, or naturally healing the vulnerable transistors, potentially by raising temperatures, a process called annealing.
The full extent of the problem, and the risk it poses to the mission, will not be known for several weeks, while testing continues at JPL, the Johns Hopkins University Applied Physics Laboratory, and NASA’s Goddard Space Flight Center. But at its most simple, the problem is easy to understand, Fitzpatrick said at the meeting. “A switch would not work when we need it to work.”
Given that the parts were ordered from Infineon for spec, and were demonstrated failing the spec (and they didn't then notify customers), it makes me wonder if there's any liability there for delays or failures. The fact that the failures came out of a classified space complicates things - Infineon could have been obligated to not report it outside cleared spaces until either a non-classified source discovered it or the flaw had been corrected in any fielded military equipment (DOD rules require any potential flaw in military equipment be held as restricted information , even if it applies to non-classified materiel).
Some detailed information from a Jul 11 2024 article in Science:
Given that the parts were ordered from Infineon for spec, and were demonstrated failing the spec (and they didn't then notify customers), it makes me wonder if there's any liability there for delays or failures. The fact that the failures came out of a classified space complicates things - Infineon could have been obligated to not report it outside cleared spaces until either a non-classified source discovered it or the flaw had been corrected in any fielded military equipment (DOD rules require any potential flaw in military equipment be held as restricted information , even if it applies to non-classified materiel).