Stellar Sphere was one of several Imperial projects developed in secret by the Tarkin Initiative. The technical schematics for Stellar Sphere were kept at the Citadel Tower on Scarif, along with those of the War-Mantle and the Death Star.
- Catalyst: A Rogue One Novel (First mentioned)
- Rogue One: A Star Wars Story novelization (Mentioned only)
- Star Wars: Rogue One: A Junior Novel (Mentioned only)