That's correct.
"Jupiter was selected over Saturn, because to do Saturn meant, in effect, getting a convincing Jupiter first -- they are fairly similar -- and then finding a way to put rings around it. Best way to do the planet was not the best way to do the rings; they could not be made at the same time, as photographic records, like our other planetary images. Putting two separate techniques together into one image would have been quite difficult, though not impossible."
-- Special photographic effects supervisor Con Pederson quoted in The Making of Kubrick's 2001, edited by Jerome Agel