[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.