Egg Jet

Doctor Eggman's rocket ship is seen at one time in Sonic the Hedgehog 2 and is possibly created by Dr. Robotnik for himself. It is a large, grey and red colored space shuttle with four wings each side and five rotors. This rocket ship also is later seen at few comic adaptations.

It is used once, when the doctor escapes from Wing Fortress Zone to his space station, the Death Egg, after he failed to capture and get rid of Sonic at the cockpit room of Wing Fortress Zone. While Sonic manages to miss the rocket ship, Tails returns with a repaired Tornado (now with a rocket add-on set below) and Sonic and Tails start chasing Eggman through the sky. After a while, Sonic manages to grab the rocket ship's side and keeps hanging on there when the rocket ship starts to rise and come close to Earth's atmosphere and docks to the Death Egg. The game then progress to Death Egg Zone, the last zone of the game. The rocket ship is not seen since then and gets possibly destroyed during the explosion of the Death Egg in the game's ending.

Sonic the Comic
The rocket ship is seen in Fleetway's Sonic the Comic issue 6's story "Attack of the Death Egg", which is seen to after the storyline adaptation of Sonic the Hedgehog 2 in the comic's run. In the story, Sonic and Tails used the rocket ship (which might be the second model) to get from Wing Fortress Zone to the floating ruins of Death Egg in space. In the comic, the rocket ship is shown to have four wings as the game originally had only two. As the Death Egg later crashes to the ocean, the rocket ship is completely destroyed.

Archie Comics
Two rocket ships have made appearances in Archie's Sonic the Hedgehog comics, based on the appearance from Sonic the Hedgehog 2, even through there are only have two wings above and under the rocket ships. The first one is used by Doctor Eggman himself in issue 229 during his quick escape from Wing Fortress to the Death Egg Mark 2, while Sonic manages to hop on the rocket ship just in time. Later as the rocket ship gets docked at the space station and Eggman with his Death Egg Robot and Sonic starts fighting, Eggman threw the rocket ship toward Sonic, destroying it at same time. While Sonic manages to dodge it, destruction of the rocket ship makes the arena go on fire.

After the GENESIS arc., Eggman is shown to have second rocket ship with different a color scheme at a storage area inside of the Death Egg Mark 2, which is used by Snively in Sonic Universe's issue 37 to escape from the space station. He used it again in the next issue, after his failure of bringing Hope along with him. It is not seen since then as Eggman later caught Snively at Stormtop Village.

Trivia

 * Eggman is known to have more space shuttles inside of his hidden pyramid base during the events of Sonic Adventure 2, as Sonic, Tails, Knuckles and Amy used one to get to the Space Colony ARK and then possibly used it to get back to the earth at the end of the game. This space shuttle apparently has heavy resemblance to American space shuttle called Discovery, which was part of NASA's Space Shuttle program.
 * While the rocket ship in Sonic the Hedgehog 2 is shown to have only two wings, others are seen hidden on the other side and thus unable to see.
 * The rocket ship in Sonic the Comic resembles an X-Wing from the Star Wars franchise.