Planetary engine

Classics War Planets.

Those who desire total conquest of Cybertron rarely want to stop there, instead envisioning the creation of a vast intergalactic imperium with Cybertron as its throne. To further this conquest and enslave the rest of the heavens, many a would-be dictator has attempted to either create or use Cybertron's unfathomably powerful planetary engines that can actually repurpose the world as an unstoppable mobile dreadnaught.

In theory.

Fiction

Generation 1 continuity family

Marvel Comics continuity

Marvel The Transformers comics

Megatron's plans to create the planetary engines, The Transformers were seen as so radical and extreme that most of Cybertronian intellectual society dismissed him as a meaningless kook. One who did not do so was the egotistical Autobot scientist Flame, who liked the idea so much he chose to appropriate it for himself. Acting covertly, Flame discovered the immense fusion engines Megatron had tried to use, and endeavored to reactivate them himself—disregarding all warnings from Xaaron that engaging the reactors would destroy the planet. Flame would be undone by his own ambition, destroyed in the reactor explosion. Meltdown!

Transformers '84

The Decepticons' plan to attach planetary turbines to Cybertron was officially known as Project Dreadnought, through which Cybertron would become a galaxy conquering warship. Megatron's increasing obsession with Optimus Prime however delayed these plans, even as his science division sought to use the turbines to guide Cybertron, since shaken from its orbit, to other worlds for resources. To try and get Megatron to refocus on galactic conquest, Shockwave test-fired one of the partly completed turbines, diverting Cybertron towards the Stellae Cimeterium. While this failed to deter Megatron's vendetta, the Dynobots were sent to the remains of the turbine, Shockwave and Skyfire managing to heavily wound them, though the battle had all but killed the former. Secrets & Lies #1

After a series of events had resulted in Straxus becoming Decepticon leader, he gave Counterpunch the authorization to restart Project Dreadnought. Secrets & Lies #3 With Abominus as a guard, the Decepticon scientific division resumed work on the project in Stanix where they were attacked by the newly minted Wreckers. The Autobot commandos were ultimately successful, managing to plant explosive charges that ripped the main planetary turbine apart, ending Project Dreadnought. Secrets & Lies #4

The Transformers cartoon

Galvatron first experimented with planetary engines on a comparatively small scale, arranging to have a set built on a comet. He intended to use them to crash the comet into Metroplex, but an attack by the Autobots destroyed the engines, and the comet was then eradicated by the sonic weaponry on the nearby planet Eurythma. Carnage in C-Minor

Galvatron later revisited the idea of planet engines when devising his master plan to punish humanity for having helped the Autobots. With the Autobots themselves largely defeated on Cybertron, Galvatron ordered the Combaticons to extract their defeated victims' power packs, then construct gigantic planetary engines—"the biggest rockets ever built!"—and use the power packs as fuel. This tactic succeeded, allowing Galvatron to pilot the planet into an Earth-orbit, at which time he attempted to use the power of the Plasma Energy Chamber to destroy the entire Solar System. Luckily for everybody (including himself), the planetary engines actually provided the means to foil Galvatron's plans, as Spike Witwicky had the Autobots' Nebulan allies reverse the rockets' polarity. With its mechanism thus reversed from "output" to "intake" (we know, we know, just go with us, okay?), the engines were used them to absorb the excess solar energy and channel it straight to Vector Sigma, preventing the explosion of the sun and revitalizing Cybertron and restoring its Golden Age. The Rebirth, Part 3

Dreamwave Generation One continuity

The planetary engines were constructed by Primus himself as he adjusted to his new body. Transformers: The Ultimate Guide Eons later, when Megatron built his underground army, he somehow came to glimpse the ancient nature of Cybertron and its potential ability to traverse the stars. Using attacks against Autobot cities as a diversion, The War Within #2 Megatron attempted to activate the giant planetary engines and turn Cybertron into a warworld—but Optimus Prime was able to defeat him. The War Within #4

2005 IDW continuity

In Cybertron's earliest days, Adaptus put forth the idea of attacking alien worlds so that the crucible of war would force the Cybertronian race to evolve. Unable to convince the rest of the Guiding Hand, Adaptus attempted to overthrow them by force only to be overwhelmed. Retreating to Luna 1, Adaptus fired an electromagnetic weapon on Cybertron, erasing the memories of the populace. Under cover of the confusion, Adaptus constructed a set of Tri-Thrusters and sailed away into the Warren. The Unremembering

In late 2012, the crew of the Lost Light rediscovered Luna 1 but failed to find Adaptus's engines. This Calamitous Life

The Autobots that had stayed behind on Luna 1 eventually discovered the engines and wrote about them in a report detailing the many mysterious findings on the moon. Prowl had trouble swallowing the existence of the engines. When Sentinel Prime returned to life, he hijacked a Titan corpse and made for the engines, Ten to Midnight intending to use their quantum foam to create a space bridge large enough to allow his Titan army passage to Cybertron. The engines eventually proved Sentinel's undoing as he was shoved down one of the thrusters by Beak. Last Light

The Functionist Universe

To enact their holy war against alien life, the Functionist Council constructed a set planetary engines so as to pilot Cybertron through the heavens. The Return of the King

Transformers vs. G.I. Joe

After Megatron perverted Vector Sigma, the supercomputer began reshaping Cybertron into a massive starship that would cyberform the galaxy. Expelled from the Garden As part of the process, Cybertron's north pole sprouted a continent's worth of planetary engines that guided the planet through space. When G.I. Joe invaded Cybertron, they marked the site for a bombardment of green bombs. Though the artillery struck, Form Follows Function Cybertron's movement through space was unhindered. Everybody Hates Metroplex Once Megatron had been defeated, Primus sailed out of the solar system and back to his original orbit. The War Never Ends

Cybertron cartoon

Once the Unicron Singularity had been dealt with, the Jungle Planet was left far from its normal space. To fix this problem, the Autobots disassembled the Ark's engines and rebuilt them on the planet's surface to propel it through a space bridge and back to its solar system. Galvatron however crashed into one of the engines, sending the Jungle Planet on a collision course with Cybertron. The danger was negated on account of literally every Cybertronian in the galaxy physically pushing the damaged engine back into place, allowing the Jungle Planet to safely sail through the space bridge. Unfinished

Cyberverse cartoon

As part of their plan on the moon, the Decepticons constructed a set of planetary engines on the dark side of the satellite. Once their Planet Smasher had been destroyed, Shockwave activated the planetary engines to slam the moon into the Earth. Hot Rod, Wheeljack, and Prowl, after being told to not simply blow up the moon, managed to hack into the engines and reverse the moon's trajectory, returning it to its original orbit. Bad Moon Rising

Games

Transformers Legends

Megatron aimed to use the planetary engines to wipe the Autobots out in one decisive move. The War Within

Notes

• The Marvel and Dreamwave comic treatments of Cybertron's planetary engines are vaguely similar, which makes sense since they were both written by Simon Furman and there are some themes he is fond of revisiting. Though the cartoon's portrayal lacks the ancient historic tie-ins, it is notable (albeit almost certainly coincidental) that once again the idea for the giant engines comes from Megatron—or at least, the guy who was built from him.
• Galvatron was really into planetary engines in the Generation 1 cartoon—in addition to their appearances in "Carnage in C-Minor" and "The Rebirth", an aborted plotline from "Fight or Flee" involved planetary engines being built on Paradron in order to turn the planet into a mobile fortress. The Japanese sequel series The Headmasters would arguably take this trend to its logical conclusion with the Grand Galvatron plan.
• An idea for Junkion in the earlier script draft for The Transformers: The Movie had the planet being mobile. Some vestiges of this concept remain in the final product, such as Wreck-Gar's line that the "new, improved Junkion planet is sleek, sexy import with turbo handling."

See also

• Unicron, the evil god who usually transforms into a planet with interstellar propulsion capabilities.