Comment by bertil

The ship doesn’t need to touch the ground, but you need to attach it firmly (because as soon as you unload a ton, that ship wants to jump up by about a ton). You can mitigate some of that with helium pumps and pointing the engines up and down, but a firm cabling would be necessary. In a pinch, I assume you can drop the necessary equipment to attach cables from the ship itself (it will still jolt when you do that).