Expeditionary Battle Planetoid

"Impossibly huge. A schoolboy fancy?"
"Not at all. Quite doable, though expensive."

―Raith Sienar, presenting his design to Commander Wilhuff Tarkin^[1]

The Expeditionary Battle Planetoid was a theoretical spherical battle station conceptualized by Raith Sienar in 29 BBY. It was one of the precursors to the finalized Death Stars.^[1]

Description

"It's a dream, but an achievable dream, given certain advances in hypermatter technology. An implosion core with a plasma about a kilometer in diameter could power an artificial construct the size of a small moon. A couple of large ice asteroids for fuel…common enough still in the outer fringe systems…"

―Raith Sienar^[1]

The Expeditionary Battle Planetoid was the first true precursor to the designs that would eventually give birth to the Death Star project. The design was similar to the Death Star with a massive planet-devastating turbolaser powered by its core, but this design was deemed impractical due to the immense power generation needed to fuel such a weapon.^[2] It would have been powered by an inner plasma implosion core over a kilometer wide. Raith Sienar planned to fuel it using large ice asteroids that were common in the Outer Rim systems. It also included two smaller spheres, attached to the poles of the main sphere (which was around 90-100 kilometers wide). Sienar considered removing these spheres to make the design more wieldy for transport.^[1]

History

"What a sense of scale! What unutterable power!"

―Wilhuff Tarkin^[1]

Raith Sienar began designing the Expeditionary Battle Planetoid in 29 BBY. While the project's construction would be highly expensive, Sienar was confident that it was completely doable. The battle station served as one of Sienar's show projects that he would show to potential clients and contractors with grandiose taste to impress them. He displayed its schematics to representatives of the Trade Federation, but they showed no interest in it due to their lack of imagination, according to Sienar.^[1]

Around the time of the Second Battle of Zonama Sekot, Raith Sienar presented the plans for the Battle Planetoid to Republic Outland Regions Security Force Commander Wilhuff Tarkin, who was enamored of the idea.^[1] Tarkin turned around and showed the plans to then-Supreme Chancellor Palpatine, taking credit for them as well. Sienar, however, had since abandoned the idea of developing the weapon himself, and appeared indifferent to the apparent backstabbing.^[3]

In 29 BBY, the design was still considered impossible, as it required particular advances in hypermatter technology in order to become fully feasible.^[1] The issues were solved by 22 BBY (and were the cause of Republic Sienar Systems' grant to the Ministry of Science for hypermatter research) thanks to the advances made by the engineer Bevel Lemelisk .^[4]^[2]

With the formation of the Confederacy of Independent Systems in the months before the outbreak of the Clone Wars, Palpatine—as Darth Sidious—gave the plans to his Sith apprentice and Confederate leader, Count Dooku. The Geonosians took the designs and from them developed their Ultimate Weapon, transforming the Battle Planetoid with a functional superlaser into a planet-killing superweapon.

After the Declaration of a New Order in 19 BBY, the Ultimate Weapon's design was refined into that of the Death Star, and construction on the station began and, ostensibly as a reward for "his" design, Tarkin became the Moff overseeing the project.