(Explorer8939) wrote in
om:

Does Hubble perform observations while in direct sunlight (ie the
period of its orbit when it is not in the Earth's shadow.

Yes. Because it operates in a vacuum, light scattering is not
a problem; the only constraint is not pointing too closely in the
direction of the Sun and Moon (usually), and the Earth (obviously).

If not, then a propulsion system like that of Orbital Recovery could
be used to change the Hubble orbit while Hubble was not being used (ie
when on the sunlit portion of its orbit).

Hubble does not use a propulsion system, to prevent contamination of
the precision optics. Pointing is accomplished by flywheels and
magnetic torquers.

Something like an orbital tug could be occasionally useful for tasks
like this, however.

--Damon