NASA's Galileo spacecraft, launched in 1989, was the only space mission to make
repeated visits to Europa, passing close by the moon
about a
dozen times.
Rough calculations show if you drill
about a
dozen mine shafts as deep as possible into the thing, and plunk megaton nuclear bombs down there, and then fire them off simultaneously, you'll get a
repeat of the Long Valley Caldera explosion of
about 800,000 years ago — which coated everything east of it with miles of ash and injected a giant aerosol cloud into the stratosphere — the ash layer alone formed a triangle stretching from the caldera to Louisiana to North Dakota, including all of Arizona and most of Idaho and everything in between — I bet that would have a cooling factor of at least -30 W / m ^ 2 — and you could go and do the Yellowstone Plateau at the same
time — geoengineering at its finest.