From the Super Mario Wiki
Mushroom Starfighters are small, one-seated spacecrafts created for outer space combat, owned by the Mushroom Colony. They appear to be made out of large pipes. Mushroom Starfighters only appeared in The Super Mario Bros. Super Show! episode "Star Koopa".
Mario, Luigi, Princess Toadstool and Toad arrived at the Mushroom Colony with only fifteen minutes left before the colony's entire planet was to be destroyed by Darth Koopa's Birdo Ray. With little time left to react, head colonist Obi-Wan Toadi suggested that Mario and his friends each take control of a Mushroom Starfighter, in order to breach Koop Star.
After agreeing, Mario and his friends took off in Mushroom Starfighters, where they fought against Stormtroopa Starfighters in outer space. Mario's group succeeded in defeating the Stormtroopas, all while staying alive. Mario then braved a trench indentation along the surface of Koop Star in his Mushroom Starfighter, evading enemy attacks with some help from Toad. Mario then entered Koop Star, and blew up the foundation with a Bob-omb, which ultimately blew up Koop Star as a whole.
Afterward, Mario and his friends flew back in their Mushroom Starfighters to the Mushroom Colony, where they were congratulated by Obi-Wan Toadi and the other colonists.