What is the Space Disco?

Space Disco is a time-limited event consisting of 10 steps. Each step has its own goal and rewards. You can collect fuel by beating levels.
When you reach the goal of a step, you can claim your rewards, then move on to the next step.
You don't win extra fuel from Hard and Super Hard levels.
At the start of each step, you have 3 rockets. When you lose a level, you lose one rocket. If you lose all your rockets, you fall to the start of the current step, and then you will have 3 rockets again.