Cool MB, and a good thread idea. It's interesting how many geostationary satellites there are. You can see on:
NASA - Science@NASA J-Track 3D
We're building a little ring around our planet
I read something interesting in the delay of STS-127,
It seems that if the
beta angel exceeds 60 degrees at any time during docking procedures then it isn't safe to dock making cutouts that are apparently weeks long. That strikes me as a rather drastic design limitation—really limiting launch windows. Of course, I don't really know anything about the design so I can only imagine there is a good reason for the cutout and why it wasn't designed around when the ISS was built. I just had never heard of it and found it interesting.
Quote:
Throw a docked orbiter into the mix and you have a third constraint,
shuttle thermal control. The attitude of the orbiter/ISS stack must be
chosen to satisfy ISS power/thermal constraints and shuttle thermal
constraints. It turns out that at beta angles larger than 60 degrees,
there is no attitude that satisfies all three. So the shuttle program has
a launch window cutout when the beta angle will exceed 60 degrees at any
time during docked ops.
These cutouts occur around the solstices, because that's the time of year
when the sun's declination is farthest north (summer) or south (winter)
and so the odds are greatest that the sum of the sun's declination and
the orbit inclination will exceed 60 degrees. The summer cutout affects
night launches and the winter cutout affects day launches. The shuttle
return-to-flight restriction on night launches has effectively mooted the
summer beta cutout, but the combination of the night launch restriction
and the winter beta cutout makes winter launch opportunities few and far-
between.
Re: launch windows
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~modest
