"All spacecraft come with an expiration date: They can only travel as far as the fuel onboard allows.

This is one of the biggest obstacles we face in attempting to explore deep space.

But an experiment spearheaded by the Planetary Society may be a step toward addressing that problem. The group launched a satellite called LightSail 2 on June 25; it's designed to be the first-ever spacecraft propelled solely by sunlight."

https://www.businessinsider.com/worlds-first-ever-solar-sail-unfurling-in-orbit-2019-7