Robbie Rider is the younger brother of Richard Rider, also known as the cosmic hero Nova, and the son of Charles and Gloria Rider. Robbie is a scientific genius who achieved independent wealth through software development. He helped out his brother more then once, although he never knew his brother was actually the superhero Nova.
Mayor Story Arcs
When the Skrull Invasion of Earth began, Robbie Rider was working at the P.E.G.A.S.U.S. Project, an American facility full of alien weapons and technology. Due to the importance and potential threat of this facility, it became a primary Skrull target. When Nova returned to Earth after learning of the invasion, he found out from his parents that his brother was potentially in danger. He went to the P.E.G.A.S.U.S. Project to make sure Robbie was okay. When he arrived, he found out that the facility had already been attacked once. The security forces there, led by Darkhawk, believed Nova to be a Skrull, but it was Robbie who vouched for him and proved the Nova was who he said he was.
Robbie helped revive Worldmind, the Nova Corps super computer, who helped turn the tide of the battle. After the surprising return of the Nova Corps and the consequent defeat of the Skrulls, Robbie felt that he was still under the shadow of his big brother. But everything changed the moment that Worldmind selected him as a new member of the Nova Corps. Nova was against Worldmind's decision to rebuild the Corps so quickly and Robbie thought it was because Nova was jealous that he wasn't the only brother with super powers anymore.
War of Kings and Thanos Imperative
Robbie remained with the newly established Nova Corps and fought in the war known as the War of Kings, between the Shi'ar Empire let by the earth mutant Vulcan and the Kree Empire led by the Inhumans. When the Nova Corps was scattered around the battlefield, and Richard Rider was nowhere to be found, Robbie took on one of the biggest threads all by himself and even managed to defeat him. This greatly increased his confidence. Robbie remains a Nova Centurion til this day, even after the events of the Thanos Imperative, in which Robbie's brother seemingly sacrificed himself.
In Earth-9442 Robert Rider received the Nova Force instead of Rich because of his higher intellect and became the hero known as Nova 0:0. He also mange to improve the use of his powers, as he could jump to different realities by gathering energy.