Interorbital light sails Like wind, sunlight exerts pressure.
However, in orbital space, if you make a large sail out of thin aluminum reflective material, you can go places without any propellant, merely using the pressure of the sun. However, you need to control your sails so that you go where you want to go. Thus, you have flexibility in maneuvering, assuming you have well designed sails. Notably, going straight out from the Sun is not useful for achieving into a higher orbit, and just makes your orbit more elliptical, passing back thru the point where it was when the sail was deployed. The component of force which increases angular momentum is what produces useful changes to orbital parameters.