Upper Platform

I would engineer a spaceflight from a similar upper platform attached to the nominal buoy. Up another 25km or so, a smaller spherical launch plate with scientific equipment and a specially heat treated pad, and the floating platform fitted with balloons in the event of being exposed to massive heat to dissipate it without popping the platform or changing its buoyancy significantly.

From here, rockets would launch into space missions. Their primary chamber would be water to be split into HHO and combusted out, dropped onto the platform and planet. The chamber that the water is held in could be collapseable. It might be good to have some room there. Other equipment can be held in the water in the meantime, and the added mass of the water chamber should not be an obstacle, as the secondary power source will be the contained-chemical-circuit [CCC] water splitter with fuel cell, producing electricity at a steady rate for the ship and held optionally in a superconductor, or with the use of an MEG if it does not interfere with the ship's signals. This is an ideal setting for a modified ion engine and other superconductor tests.