I transistor utilizzati su Europa Clipper si sono rivelati molto meno resistenti del previsto alle radiazioni e potrebbero fallire durante la missione. A riportarlo è stata la stessa NASA in un comunicato di fine maggio e in un aggiornamento di due giorni fa (entrambi dal titolo piuttosto anonimo, anche considerata l’apparente serietà del problema).
NASA Examines Electrical Switches on Europa Clipper Spacecraft
The mission team at NASA’s Jet Propulsion Laboratory in Southern California, which manages the mission, is assessing test data that indicates some transistors could be affected by significantly lower radiation levels in some conditions.
NASA Continues Assessing Electrical Switches on Europa Clipper
In June 2024, an industry alert was sent out to notify users of this issue. The manufacturer is working with the mission team to support ongoing radiation test and analysis efforts in order to better understand the risk of using these parts on the Europa Clipper spacecraft.
Testing data obtained so far indicates some transistors are likely to fail in the high-radiation environment near Jupiter and its moon Europa because the parts are not as radiation resistant as expected. The team is working to determine how many transistors may be susceptible and how they will perform in-flight. NASA is evaluating options for maximizing the transistors’ longevity in the Jupiter system. A preliminary analysis is expected to be complete in late July.
Ars Technica ha ripreso la notizia fornendo qualche ulteriore dettaglio.
At a meeting of the Space Studies Board in early June, Jordan Evans, project manager for the Europa Clipper Mission, said it was his No. 1 concern ahead of launch. “Five weeks ago today, I got an email that a non-NASA customer had done some testing on these rad-hard parts and found that they were going before (the specifications), at radiation levels significantly lower than what we qualified them to as we did our parts procurement, and others in the industry had as well. What keeps me awake right now is the uncertainty associated with the MOSFETs and the residual risk that we will take on with that,” Evans said in June. “It’s difficult to do the kind of low-dose rate testing in the timeframes that we have until launch. So we’re gathering as much data as we can, including from missions like Juno, to better understand what residual risk we might launch with.”