[X] My Assistant

[nprev]

The spacecraft has entered its preliminary design review phase, so I think it's time to begin discussion of what promises to be a fascinating journey to one of the most interesting destinations in the Solar System. Dr. Robert Pappalardo, the mission's chief scientist, delivered an overview of Europa as well as a top-level description of instrumentation and objectives during a talk tonight at the Griffith Observatory as part of their monthly "All Space Considered" series, so that serves as a good starting point. His presentation starts at 29:35.

As a reminder, please carefully review rule 1.3 before commenting. In fact, please review all of them. Thanks!


Europa Clipper Presentation (29:35)

[Holder of the Tw...]

Designed right, tested right, and then learn that a supplier failed to meet specs ...

Shades of Psyche.

[StargazeInWonder]

The headline and one quote inside offer optimism, but there isn't much basis in specifics offered.

As it happens, there's also some Mars Sample Return commentary.

https://spacenews.com/nasa-science-head-opt...es-on-schedule/

[StargazeInWonder]

For the news to raise that concern about the MOSFETs, followed by weeks without an update seems like a disconnect, at least as far as communications go. One tweet briefly says that two inside sources expect the launch to go ahead, but there isn't anything public that addresses the issue. I guess that either the investigation is continuing silently and in parallel with launch preparations or it has concluded silently. In about 7 weeks, we'll either have a mission on the way or some implicit statement that the MOSFET issue has been addressed one way or another.

[mcaplinger]

For the news to raise that concern about the MOSFETs, followed by weeks without an update seems like a disconnect, at least as far as communications go.

It is a little surprising that there hasn't been an update.

Speaking only from my experience, many parts are sensitive not only to the total radiation dose but also the dose rate (see, for example, "Dose-Rate Sensitivity of 65-nm MOSFETs Exposed to Ultrahigh Doses" https://ieeexplore.ieee.org/document/8340851 )

Since vendors can only test at a limited number of dose rates, and it's very difficult to predict what the actual dose rates experienced in flight will be, this may be difficult to nail down as well as one might like. A part could be fine at one dose rate and fail much sooner at another.