Quantum Mechanics
The Quantum Leap Subspace Portal operates on the principles of Quantum Mechanics, which is like... well, you'll probably figure it out as you go along.
Just remember, you can only travel through space, not time. That's just not how this works.
Fuel Consumption
This ship runs on a special brand of Quantum Fuel, which is only available at the local intergalactic gas station.
Don't try to use regular old gasoline, or you'll end up with a ship that's just as lost as you are.