A Soyuz spacecraft digital clock teardown #Space #Teardown @kenshirriff
Ken Shirriff posts about obtaining a clock that flew on a Soyuz space mission. The clock, manufactured in 1984, contains over 100 integrated circuits on ten circuit boards. Why is the clock so complicated?
In the blog post, Ken examines the clock’s circuitry and explains why so many chips were needed. The clock provides a glimpse into the little-known world of Soviet aerospace electronics and how it differs from western methods.
Removing the clock’s cover revealed a dense stack of circuit boards. The clock was much more complex than expected:
(The clock had) ten circuit boards crammed full of surface-mount ICs and other components. The components are mounted on two-layer printed-circuit boards, a common construction technique. The boards use a mixture of through-hole components and surface-mount components. That is, components such as resistors and capacitors were mounted by inserting their leads through holes in the boards.
The surface-mount integrated circuits, on the other hand, were soldered to pads on top of the board. This is more advanced than 1984-era American consumer electronics, which typically used larger through-hole integrated circuits and didn’t move to surface-mount ICs until the late 1980s. (American aerospace computers, in contrast, had used surface-mount ICs since the 1960s.)
See Ken’s post for a full teardown and analysis.