Europa Clipper mission threatened by faulty transistors
Engineers have learned that transistors installed on NASA’s Europa Clipper mission were not built to the right specifications and could fail in the harsh environment surrounding Jupiter.
The issue with the transistors came to light in May when the mission team was advised that similar parts were failing at lower radiation doses than expected. 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.
This issue could be disaster for the mission, which has a launch window that opens on October 10, 2024. If it is impossible to replace the bad transistors, NASA will be faced with two choices, neither great. It could launch regardless and hope for the best. It could delay the mission to fix the problem, which might involve a delay of years waiting for a new launch window.
This story appears to illustrate once again the decline in quality control that appears to be happening across much of American industry. The technology for building radiation-hardened equipment has been standard for decades. For a company to deliver equipment below standard now suggests incompetence or fraud, neither of which speaks well for it and the entire industry.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon. from any other book seller, or direct from my ebook publisher, ebookit.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Engineers have learned that transistors installed on NASA’s Europa Clipper mission were not built to the right specifications and could fail in the harsh environment surrounding Jupiter.
The issue with the transistors came to light in May when the mission team was advised that similar parts were failing at lower radiation doses than expected. 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.
This issue could be disaster for the mission, which has a launch window that opens on October 10, 2024. If it is impossible to replace the bad transistors, NASA will be faced with two choices, neither great. It could launch regardless and hope for the best. It could delay the mission to fix the problem, which might involve a delay of years waiting for a new launch window.
This story appears to illustrate once again the decline in quality control that appears to be happening across much of American industry. The technology for building radiation-hardened equipment has been standard for decades. For a company to deliver equipment below standard now suggests incompetence or fraud, neither of which speaks well for it and the entire industry.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon. from any other book seller, or direct from my ebook publisher, ebookit. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Minor edit in last paragraph: “The technology for building radiation-hardened equipment has been standard for decades.”
$50 bucks says they came from the same country that sold Boeing fake titanium.
The Babylon Bee will tell us who done it within 48 hours!
Andi: What would I do without you? Thank you. Fixed.
It turns out that the chips (called MOSFETs) were sourced from a German semi-conductor firm! The article which broke the story yesterday mentions this – it is from the New York Times, about which I would be skeptical, but it’s actually a free-lance article by David Brown, who authored a pretty good book on Europa Clipper’s development last year, so he does have good sources in the program and knows what he is talking about:
The chips currently in Europa Clipper are manufactured by Infineon Technologies, a German semiconductor firm. They are also used in military spacecraft. An Infineon spokesperson declined to comment on “actual or potential customers,” but said that the company has “stringent processes in place to ensure compliance with all relevant quality and performance standards for our products.”
https://www.nytimes.com/2024/07/11/science/europa-clipper-nasa-radiation.html?unlocked_article_code=1.6k0.-Ag8.LypxgeYjpcI4&smid=url-share
A key difficulty is that the transistors cannot simply be replaced. Europa Clipper’s aluminum-zinc electronics vault, meant to provide a measure of radiation resistance, was sealed in October 2023. So JPL is now attempting to determine if the faulty MOSFETs will cause catastrophic failure once they undergo high radiation. Otherwise, the launch may have to be cancelled, and the MOSFETs replaced – a painstaking process that could take several months to a year. Backup windows are available over the next 2 years.
Meanwhile, there are going to be some hard questions about why Infineon did not communicate this problem to JPL.
So where does this leave NASA? As noted, they are frantically running tests to determine the reliability of these MOSFETs, which will be completed later this month. As for what happens after that, Eric Berger reports:
NASA’s update is silent on whether the spacecraft could still make its approximately three-week launch window this year, which gets Clipper to the Jovian system in 2030.
Ars reached out to several experts familiar with the Clipper mission to gauge the likelihood that it would make the October launch window, and opinions were mixed. The consensus view was between a 40 to 60 percent chance of becoming comfortable enough with the issue to launch this fall. If NASA engineers cannot become confident with the existing setup, the transistors would need to be replaced.
https://arstechnica.com/space/2024/07/nasas-flagship-mission-to-europa-has-a-problem-vulnerability-to-radiation/
I think we should all steel ourselves for a multi-year delay in the launch of this mission. Which would stink. But it beats sending it out there and having it fail, or even fail partially, like Galileo did because NASA failed to catch the problems that had developed in its high gain antenna while it had been in storage.
And now it’s very launch choice has delays.
They were too good to fly atop SLS.
Ironically, if they had decided to ruggedize the electronics for solids–that didn’t break Webb mind you–the current problems might not exist.
Karma
Wow, Jeff Wright, so many problems in three sentences.
The decision not to fly on SLS had three major factors: 1. It was essentially a given that no SLS vehicle would be available. The Artemis program is fully utilizing all the SLS vehicles that can currently be produced. Even if you could convince the Artemis program to give up the second vehicle, it’s not going to be ready on time anyways. 2. Cost. They already pared down the mission design quite a bit for cost reasons, coming up with the $billion+ to use SLS instead of Falcon Heavy was simply not in the budget. 3. Vibration. And not just “solids vibrate”, but “the specific configuration of SLS vibrates more and differently than any other launcher previously modeled.
And contrary to your “if they had decided to ruggedize” they actually had to make the mission vehicles more robust to use Falcon Heavy, as the flight profile for the lower energy transfer puts them closer to the sun. But in either case, it has nothing to do with the specific problem of radiation hardened electronics. Microchips use wires that are very small, and very close to each other, originally on the “micro” scale, hence the name, but in modern transistors, it’s now on the “nano” scale. At that scale, a cosmic ray hitting the circuits can cause shorts, overloads, spurious voltage levels, etc. Hardening against this usually consists of a combination of using different substrate and conductor materials than in commercial chips, using lithography scales that are about 10 generations behind the leading edge (The processors in an Orion capsule are vintage 2002), and finally putting in some shielding layers to attenuate cosmic rays before they reach the chips in the first place.
It seems that the German provider of these transistors did their analysis of what their margins needed to be wrong. There are massive incentives on these instruments to get closer to modern scales, but you have to do a balancing act. And as we’ve recently seen with the Dragon, Orion, and Starline parachutes, the Dragon heatshield, and the survival of large pieces of Dragon trunk components through re-entry, a lot of what the aerospace engineering community “knew” turns out to be incorrect.
Hello David,
Nice explanation all around. Thanks for that.
There may not be a Falcon Heavy available either. SLS upper stage performed just fine.
Culberson–who fought for SLS is the only reason Clipper exists
There is an old saying
“Dance with them that brung ya”
Jeff, are you seriously trying to claim that one successful test mission proves that SLS is more reliable than Falcon after 365 consecutive missions with no failures?
“Dance with them that brung ya” — as David says, that rocket has only been to the dance once!
But even if you want to hang your hat on the Delta IV upper stage (which is, for the most part, what the SLS ICPS is), that’s an upper stage with only 46 launches (45 of them successful) under its belt, against a 361/364 record for Falcon 9’s second stage – which includes a streak of 298 that just ended this week.
But no one seriously expects it will take SpaceX very long to diagnose and rectify what happened with Starlink 9-3. Falcon Block 5 remains the most dependable launch vehicle in human history. Putting Europa Clipper on it was and still is a no-brainer.
I hope JPL and NASA did not farm this out to the lowest bidder.