At some point, Sunstreaker boarded the Ark along with several other Autobots.
When Optimus Prime and the others were captured by the Quintessons, the remaining Autobots aboard the Ark contemplated their next move. As pilot of the Ark, Sideswipe remained nominally in charge. Sunstreaker remained cavalier about the situation, boasting that he, Mirage, Trailbreaker, and Bluestreak could assemble a simple strike force to rescue the big guy and their friends. Still, Sideswipe cautioned his brother to wait until repairs were done and they knew what the Decepticons were up to.
As Sideswipe flew the Autobot spaceship through the Quintesson artillery, Sunstreaker and the rest of Strike Force Zero dropped from the ship to reinforce their fellow Autobots, who had already broken free and had engaged the Sharkticons.