Atmospheric entry

Re-entry is the process of a spacecraft or other object entering the atmosphere of a planet. It is most commonly used when referring to the re-entry of Kerbin. Re-entry is often the most dangerous point of the mission, as any parts not protected will be destroyed.

Surviving Re-entry

Surviving re-entry depends on the structural integrity of your spacecraft and the density of the atmosphere you are entering. Most objects will survive re-entry of any planet no matter how they enter the atmosphere (until they hit the ground). However, there are two exceptions.

Solar Panels and Re-entry

Solare panels are the only objects that will be destroyed during re-entry. Solar panels will be destroyed ALWAYS unless they are retracted. Any extracted solar panels are broken apart. If your returning to Kerbin then it's quite a fun site to watch, but it can be a danger to probes on other planets. In extreme cases, it is possible for solar panels (without the protective casing) to be destroyed despite being retracted, though this only occurs on Eve.

Physics Warp and Re-entry

While solar panels are the most fragile objects during re-entry, a spacecraft will be easily obliterated during re-entry of any planet (with an atmosphere) if physics warp is activated. It is advised not to activate physics warp with a ship with a parachute until the chute opens. Parachutes that have opened can survive physics warp x3 on Kerbin.

Kerbals and re-entry

With their protective spacesuits, Kerbals can survive re-entry. Of course, they will be completely obliterated once hitting the ground.