[FPSPACE] Soyuz Spin

[james oberg]

>From the ISS Staus Report: "Tonight, at about 4:30pm, Flight Day 2 (FD2) will begin on DO12 (end of crew sleep), featuring the third orbit adjust burn (~12:27am EDT) and initiation of ISK sun-spinning ("barbecue") attitude for Soyuz."  

'Barbeque' for Apollo was a spin along the Apollo long axis, with that axis perpendicular to the spacecraft-sun line. That is, the mode subjected all sides of the Apollo to equal shares of solar heating.

But as I recall, the spin stabilization for Soyuz is to spin the plane of the solar arrays around an axis that is parallel to the spacecraft-sun line -- that is, it keeps the solar arrays full face to the Sun, does NOT distribute solar heating equally.

The differences were because Soyuz is in low earth orbit and has substantial heating from Earth, whether its facing the Sun or not. Apollo was in Earth-Moon-Earth transit, and in deep space, so the only heating was from the Sun.

Do I understand this correctly?

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