I liked how the rotation would basically use the baricenter between the two objects to rotate around based on your thrust, however it did make for some very frustrating times where my ship would do nothing but rotate the wrong way. The Hauler module was a nice change to that, except that the asteroids would continually fall out of it in between the thrusters and the capsule. I'm not sure if this was intentional or a bug, but I feel like the scaffolding really needs to contain the asteroids as well. It was just so frustrating to have to constantly slow down and go back because my cargo had fallen out behind me.
I'm a sucker for games that use fairly accurate space physics, so I liked this despite how frustrating it could sometimes be. Nice job.

I like your idea, although it is very hardcore and inherently ambitious (simulator).

A few comments about game and code: 

1) Relative to the rotation of the spacecraft. Although the possibility of direct activation of the RCS does exist, in fact, the rotation of aircraft and spacecraft is controlled either by setting the angular velocity or by setting the angle of rotation. In general, it would be good to develop a simple regulator for controlling the angular velocity of the spacecraft. 

2) And I looked at your source code, and I can say that you do not need to manually attach the activation of the engine to a particular button and there is no need for pre-manual distribution of thruster in directions, instead, in simple cases, you can use a dot-product to determine which engines are directed in the right direction for the desired movement and rotation, for example, like in my example in Activation method. I don't set any threshold in this example, because this script does not interact with physics, but is only needed for special effects, but you can set a special threshold (for example, if dot-product is greater than 0.5). This works well if your engines are directed orthogonally or collinearly to each other. You can see how this works in practice in the demonstration of my other old example.

Unfortunately couldn't figure out how to stop spinning uncontrollably.  Seeing comments I figured that many players had the same issue, but figured it out after a while of playing. Since I'm not a fan of the genre, I didn't have enough patience.

The tutorial although thorough was a bit overwhelming. I wish it was given step by step as you play, but I do understand that there were resource/time limitations that probably prevented this.

Cool graphics, I liked the scale, adding the zoom feature was smart. Controlling the ship was difficult, but that's the point I guess and adds a level of realism. I found the tutorial to be a little long - maybe make it interactive  or have a small tutorial level before releasing the player into the full sized solar system?

Protip: Crashing into space rock stops you from spinning uncontrollably haha

Had lots of fun with this and it reminded my of my physics classes. I liked the attention to detail with the movement and it's care made the game really immersive. Good job

Really cool physics game! It takes a while to get the hang of the controls, but after that initial learning curve you're dashing around making calculated moves and big brain maneuvers. It's much more proactive than reactive, it's about planning your trajectory rather than making it on the go. Now, for the creator, I couldn't build the scanning station things on the surface of the planets. I landed correctly, pressed 1, clicked, and nothing would happen. The first time I reached it I landed badly and couldn't build  the station, so I thought "maybe I can't build it because I botched the landing?", then I self destructed, returned, botched it again, tried to build anyway and nothing would happen, then I finally landed correctly but I still couldn't build. What was I doing wrong?