What attitude have past and modern manned spacecraft maintain(ed) relative to Earth?

Question

I hope this question is not too broad. It is inspired by another question.

We know that ISS keeps its nadir pointing to Earth's surface.

What about other manned spacecraft?

Do/did they have distinct modes of attitude to Earth? What were motivations of spacecraft attitudes? I couldn't find info for most of historic manned spacecraft, at least now...

Skylab was keeping orientation to maximize insolation of fixed solar panels.

• Did Mir, Salyut space stations do the same as Skylab? (I suppose yes but have no proof)

• Did Mercury, Gemini craft have attitude requirements relative to Earth?

• Did Apollo have attitude requirements relative to Earth in different phases of missions? (I know at least in lunar transfer it was spin-stabilised)

  According to ESA site Soyuz spacecraft are spin-stabilised during long 2-day flights, with rotation axis perpendicular to sunlight to maximize insolation of solar panels. During short 6-hour flights Soyuzes are not spin-stabilised. But there is no info what is attitude mode in the short-flight case.

• Did Space Shuttle have attitude requirements relative to Earth?

Answer 1

I believe the shuttle normally orbited upside-down, i.e. with its upward axis pointing towards Earth's surface, though it would maneuver into other attitudes as needed during a mission. It was oriented retrograde (tail-first) to minimize the danger from orbital debris impacts.

In the first Mercury sub-orbital flights, there was very little time between MECO and preparation for re-entry, so the capsule immediately rotated into a tail-first attitude to present the heat shield for re-entry.

In the orbital Mercury flights, the default was to stay in that retrograde attitude, but a major purpose of the missions was to test manual and automatic attitude control. Often the capsule would be held with a substantial downward pitch so the astronaut could observe Earth's surface.

Likewise, the Gemini flights were often testing orbital maneuvering, so they would maneuver as needed, but again I think the default attitude was tail-first, head-up. During Ed White's spacewalk, the capsule appears to be in retrograde attitude, perhaps a little nose-down.

Apollo, on lunar missions, I believe stayed in prograde attitude from orbital insertion until it was coasting translunar -- it was attached to a rather large rocket stage, so wouldn't maneuver casually. After extracting the lunar module, it would orient itself north-south and roll on its long axis for thermal control. On the earth orbit missions it would be oriented according to the needs of whatever test it was carrying out; I don't know what its default was, but probably either prograde or retrograde, head-up.

Mir was the first Russian station to have reaction wheels for attitude control; I assume it maintained a constant orientation relative to Earth's surface like ISS does. The Salyuts may have drifted much of the time in order to conserve attitude control propellant.