commanded the space station to hold its position. This caused the
onboard computerto fire nitrogenthrusters,arrestingSkylab's
rotation. Although the attitudecontrol system hadn't been used in
over four years, the system performedperfectlyand within several
minutes the space station had settleddown and had gone into a
stable positionpointed within 20° of the Sun.
Flight controllersmanuallymaneuveredthe Skylab in roll
and pitch to center the vehicle on the Sun. The gravity gradien
forces then settled the Skylab into the orbital plane flying rear
end first and flight controllershad to yaw the vehicle 180° to
turn it around so it was flying in the proper direction.
Before the time Skylab was capturedout of its wobbling and
spinningpositionand stabilized,electricpower from the solar
panels was available only when illuminatedby the Sun. The ground
team had to get the space station into a positionwith the solar
panels exposed continuouslyto the Sun so Skylab'sbatteries could be
continuouslycharged and the rest of the planned activitiescould
be performedwith sufficientelectricalenergy. The vehicle solar
inertialposition is the best attitudefor this since the vehicle
tracks the Sun with the solar panels always into the Sun.