[osamagirl69]

I am sure there are better presentations out there, but this conference proceedings has some great pictures of the control systems in JWST [1]

I was also able to find a high resolution picture of the spacewire interface card with its glorious space grade asic packages [2]

Sadly the SSR is not shown, I assume that it is basically a gigantic sheet of sram and a fpga.

[1] https://www.researchgate.net/publication/233962152_Status_of...

[2] https://www.nasa.gov/vision/universe/watchtheskies/jwst_spac...

[bXVsbGVy]

> The JWST ICDH team delivered the SpaceWire technology – which is packaged in a digital, low power (1.5W), high speed (66Mbps) Field-Programmable Gate Array (FPGA) computer chip

The concepts of "low power" and "high speed" has changed a lot since JWST was designed.

[nine_k]

I think you're forgetting to factor in the distance.

Say, a low-power, high-speed interface which is USB 3.2 only works via good copper cables and at distances of a few meters.

[justinjlynn]

Indeed.Given that the design process started almost 25 years ago, I'd be more surprised if it had changed less than it has.

[progbits]

In [2], especially on the second picture z you can see some solder joints are not consistent or perfect: convex rather than concave fillets and differing amounts of solder.

Now of course it still looks better than most commercial PCBs and far ahead of anything I ever made. But I was expecting a board flying to space to be "perfect", touched up by a gray haired wizard.

How come? Is this actually plenty good, do they cover this in so much conformal coating there is no chance of joint breaking due to vibration and thermal cycling, or what?

Btw the large square packages in the first picture look amazing.

[shadowofneptune]

Finished modules or even whole spacecraft are tested in giant ovens to make sure there are no issues with heat.

https://m.youtube.com/watch?v=5MG9Lof1m_o

[kevin_thibedeau]

These electronics tend to be hand soldered so there is less uniformity than reflow.

[jacquesm]

I looked at both boards in detail and I highly doubt they were hand soldered.