As I'm not ex Buccs don't quote me, but 62,000 lbs was the MTOW of an S2. Launch at that weight (mass) from the Ark would depend, on other factors such as wind-over-the-deck, temperature, atmospheric pressure, and not just the energy available from the catapult.
A certain ex Groupie (sic. with a passion for flying
) lives close to me and he did a tour on Buccs with the FAA so I shall enquire from the horse's mouth, unless he sees this post and does so himself.
MB