Fun story: one of my professors at MIT was involved in the construction of Voyager I. When earlier probes reported back extreme radiation around Jupiter, they built in shielding, but very shortly before launch realized it would not be enough.
His team proposed — Reynold’s wrap on key components.
Which is exactly what they did. He went to the supermarket and got aluminum foil — one sheet of which has all their signatures on the inside, in magic marker. (They didn’t tell anyone until decades later.)
The lunar module used layers of “aluminum foil” as radiation protection.