As Green Lantern, Hal Jordan patrolled the galaxy and took on many missions in space. Green Lantern was one of the founding members of the Justice League of America, along with the Flash, Aquaman, Martian Manhunter and of course, Superman, Batman, and Wonder Woman. This group first banded together when they met to fight Appellaxians invading the planet, and realized that they worked much stronger as a team than any of them could have individually.
Hal is a righteous hero with a strong willpower and an ability to overcome great fear. Those traits are what make him worthy of becoming a Green Lantern. Having a strong sense of right and wrong, Hal is guided by his own conscience rather than the general rules that most of the Green Lanterns follow. One of his most notable traits is his refusal to admit defeat even in the darkest of situations, which has allowed him to achieve victory even in the most difficult odds.
Despite his virtues, Hal is also reckless and arrogant. More than once he has left his emotions cloud his better judgment, something the Guardians berate him for. Also, Hal is especially hard on himself for allowing Parallax take control of him, which resulted in the destruction of the Green Lantern Corps. But as time passes, Hal is able to overcome his guilt and move on with his life. As a normal human being, Hal does not possess any permanent superpowers. However, when he wields his Green Lantern Ring, Hal is able to fly, shoot laser beams and create constructs from the Green Light of Willpower. Hal posseses no superhuman powers, but with his Green Lantern Ring , he can do many things that a normal human cannot like fly, create solid light constructs, forcefields, and anything the ring and his imagination will allow him to do.