Advanced Thruster Mechanics

I've always found the hydrogen thrusters the most interesting because they are the only thrusters that you actually need to think about the layout of the inside of your ship for. Atmospheric thrusters always made sense to me because, with the way the game is set up, they're the first thrusters you'll realistically use so it tracks they'll be simple to use. On the other hand, it always seemed strange to me that ion thrusters, the last thruster type you get access to, were so basic. I know it's because they were the only thrusters in the game at first and the devs just didn't change ion thrusters from their base form, but I think that SE2 is a great opportunity to change that, and make everything else more interesting!

Fans (basic atmospheric and aquatic thrusters)

Fans should be the first aerial mobility block new players try to use, and as such they should be fairly straight forwards Aesthetically they would look like. There is still room for more depth than in SE1. Fans shouldn't be destructive no matter how close to another block they are, however, they should lose efficiency the more they get covered up, so if you can't draw a straight line from any part of the thrust side of the fan to the outside of the grid then you have a problem, and a fully encased fan shouldn't work at all. The intake side of the fan should require that the space behind the fan is unpressurizable and in atmosphere or under water. This will mean a small amount of thought will need to be given to the location of the fans. I also think that fans should have some gimbal so they're able to provide a small amount of thrust at right angles to the fan direction. Not enough to act as forward thrust but enough to act as inertia dampeners while flying so that you'll finally be able to make an atmospheric ship which can have its primary forward thrust be its upwards thrust while you're leaning forward.

Additionally, I think that fans should be able to reverse thrust, flipping which side is considered the intake and which side is considered the thrust, but that should be an option in the control panel, rather than just working automatically whenever you try to thrust in the opposite direction. Finally, I think fans should be able to work in series, with additional fans not counting as obstructions for calculating fan efficiency.

Fans should be incredibly powerful, being able to move a lot of mass, but also super slow, taking ages to accelerate to any decent speed making them perfect for slow-moving starting ships, mining and trade ships and being great for teaching players any mechanics for centre of mass, or air resistance. They're less helpful for anything however that needs speed

Jets(advanced atmospheric and aquatic thrusters)

Jets are the second type of aerial mobility block available to players. And they actually are thrusters meaning they share some new mechanics with the other thrusters. There are 3 blocks important for Jets. Thruster Nozzles, which are shared by all thruster types, intakes, which double up for just taking oxygen from the atmosphere, with extra armour plating, unlike the vent. And finally the compressor. The compressor is the main jet block, and the way it works is that you need to pipe water or oxygen to your compressor, which can come from the environment or your own internal stores if you need to do that for some reason, and then you need to plumb your compressor to the Thruster Nozzle blocks.

These are much faster than regular fans, but they have the downside of requiring more complex ship internals, though not by too much. Your compressor needs to be set to work with either air or water in the control panel, allowing for that cool moment where the jets turn off when entering the water but then they power up again! When compressing water the power usage is way higher adding some challenge to making a hybrid vehicle, but not preventing it entirely. The thruster nozzles need to be set to Jet, but they will work as long as they have a compressed water or compressed air input.

Jets should be balanced so they work in any environment but they burn through water or oxygen so quickly they're not viable outside of water or air except as a last resort, because the idea of a stranded ship deciding to vent some of their atmosphere to get just that last bit of thrust they need is incredible to me! They should also be much faster at accelerating a ship, but lack the fan's gimbal properties or raw energy to force efficiency making them work best when mixed with fans.

This is great for teaching players about plumbing their ship and for easing them into more complex ship internals since a new player won't need to plumb up thrusters in every direction straight away, they can do jets in one direction and fans for everything else.

Hydrogen Thrusters (Atmospheric and space but not aquatic)

Hydrogen thrusters work mostly as they do now, but unlike jets, they don't work in water, and they don't need a special block to convert the thruster resource into something the thruster can use. The hydrogen can go straight from your storage to the thruster nozzle.

There is a special block though which is an oxidizer, which takes in hydrogen and a small amount of oxygen and allows you to boost the output of a hydrogen thruster, at the cost of it burning through some oxygen and your hydrogen way faster.

The hydrogen thrusters are balanced around teaching players how to build ships where every direction has thruster nozzles and is plumbed in. Additionally hydrogen not working under water helps to balance it a bit against jets and fans, and helps teach players about the ability to set up both hydrogen and jet internals and change which type of thrust the thrusters are using on the fly, which I think is really cool! The hydrogen boost is about leaning into the hydrogen thruster's speciality. Short bursts of high power which quickly burn through your hydrogen, without making regular hydrogen thruster use so exaggeratedly expensive as to cause problems.

Ion Thrusters (Space only)

Ion thrusters will also be changed quite a lot because they will have the thruster block behind the nozzle removed since its just uses the same nozzle as every other type of thruster now (This allows you to make every new thruster skin work with every thruster type multiplying the value of DLC blocks) The Ion thruster blocks are an ionizing chamber AND a xenon refinery. The xenon refinery needs to be plumbed into a nuclear reactor which it will use to generate Xenon gas (Working off of the fact that xenon is one of the byproducts of nuclear fission) This can then be stored in xenon tanks or in the ionising chamber itself. The ionising chamber takes xenon and electricity and when plumbed to the thrusters allows them to operate as ion thrusters. At that point they work as the ion thrusters we know and love.

Thruster nozzle as a separate block

The reason I like separating the thruster components out like that is because it makes for a more interesting progression for new players, and allows for a lot of interesting engineering challenges with the internals of the ship. It also allows ion thrusters pointing in different directions to be built closer together, and for multi-context ships to not need to have multiple entire thruster arrays, just the internals to accommodate multiple thruster types.