NASA uses a lot of gold… It isn’t for jewelry or teeth; gold is actually used on a number of spacecrafts and other items sent outside of Earth. Despite the very expensive nature of gold, it has some great properties that make it a wonderful fit for the harsh environment of space.
Unlike tin, aluminum, copper, or other metals that are typically used in foil, gold foil is actually quite unique. Gold also serves a very important feature on many spacecraft which is that it provides a fantastic barrier to radiation. The atmosphere of Earth protects us from a lot of the harmful radiation from the sun and other things in outer space, but without that protective covering, humans are susceptible to high doses of radiation. Furthermore, without the protective atmosphere of Earth, machinery and instrumentation are affected by heat through radiation. Using gold as an insulator will ensure that equipment is functioning properly and kept at the right temperature.
Another great benefit of gold is that it does not tarnish or rust in the same way other metals do. This means that gold doesn’t require a lot of upkeep or maintenance, which means the spacecraft may launch sooner. Gold is also much more malleable when stretched as compared to aluminum or copper, which makes it much easier to work with.
Lastly, gold is also used as a collection plate. Similar to the Petri dishes found used for cleanroom testing, scientists can see what types of particles hit the spacecraft while outside of Earth.
Just about everything that gets sent into space spends some time in a cleanroom. This ensures that machinery and electronics can be kept free of contamination and that we don’t send organisms from Earth to the universe. Furthermore, the gold is typically applied, tested and cleaned in the cleanroom.