Let's talk about fairings today.
Fairings are another spaceflight workhorse component, often underappreciated. It's obviously needed because the payload, which is intended to work in space, isn't designed for the flight in the atmosphere. It's quite possible during the rocket launch that the speed of the rocket is already high enough, but the atmospheric pressure around is still too, high enough, and the payload will suffer under strong dynamic loads of the incoming air. So we cover the payload with a fairing. The first Spootnik had a fairing, establishing a tradition, and pretty much all payloads after that, including today, are launched with a fairing.
But not quite all of them. The Mercury capsule flew "in the flow". Same was for the Gemini, and the Apollo. After all, manned spacecraft might need to urgently separate from the rocket, in case something goes wrong - and back in 1960-s something went wrong uncomfortably often. It's interesting that Soviet counterparts, spaceships Vostok, Voskhod and Soyuz, all flew under fairings. Soyuz had several in-flight aborts, which were handled with separating the manned capsule and fairing together - as planned. Of course Space Shuttle (and Buran) didn't have fairings. In Soviet Union there was another manned spacecraft - which never flew with people before the program was canceled - TKS, which was also launched without fairing, for similar reasons.
And yet another interesting example is Skylab - the early space station so large that fairing protected only parts of the station. Skylab was designed as a modified 3rd stage of Saturn-V, and the rocket stage most often (hi, Neutron) flies without fairing, so Skylab had that peculiar design.
Today SpaceX reuses fairings, landing them into the ocean and recovering. Rocket Lab intend to keep the fairing attached to the 1st stage. Starship will keep fairing integrated with the 2nd stage.
Some payloads prefer a lot of volume - space telescopes and space stations are examples. It would sometimes be really good to include extra mass - the built-in protection from the atmosphere - in exchange to more close integration and therefore more full use of the volume which normally is taken by the fairing. It's sad that, unfortunately, it's not always possible for rocket designers to include such an option - the space station module designers would certainly appreciate that.