Obsidian *will* be required for thruster reparation, but currently you only
need to refuel the thrusters using lava. I recommend you have another look
at the GPS on Floor 4. Music should be part of the resource pack, so feel
free to turn that on, even if only quietly. The iron mine near the ship can
be made operational by putting a minecart on the track. This will
constantly collect iron from the mines – but of course, costs iron to set
up. :)