So the last week or so of work has been in fits and starts, with RL interruptions and Easter holidays and all that jazz, but this is the first update with actual vehicles in the game! There's a set of different "tools" now which the player can scroll through (for digging, placing blocks, building vehicle parts, etc), I've been making more tweaks to the player movement and voxel loading, and you can place launch clamps and vehicle parts (just fuel tanks for the moment). So, without further ado, the summary screenshot:
The launch clamp serves several purposes - from the game's perspective, it's the join between the dynamic, mobile vehicle model and the static terrain, so I don't have to be constantly checking if the player's done something daft like removed the bottom part and left a vehicle floating in mid-air - or at least, there's only one place I have to check. It also gives somewhere for the player to move and rotate the vehicle while they're working on it, rather than pretend the player is some sort of superhuman that can lift and rotate spacecraft at will. Finally, any interface activities the player needs (like saving or loading vehicle designs) will happen through the launch clamp.
The next chunk of work is to develop the vehicle object so that it's more than just a set of parts - mechanically it needs to merge all the parts into a smaller set of render & collision meshes, add up all the fuel tanks, mass and engines so it can simulate the actual flight, and possibly track more complex details like which areas of the vehicle are air-tight.