The SFS P-s4 twin ion engine, a product of Sienar Fleet Systems, functioned as an ion drive system. Its most prominent application was in powering the TIE/LN starfighters.
Due to the absence of any mobile components, the twin ion engine required minimal upkeep. In addition, it was celebrated as the most precisely engineered propulsion technology throughout the galaxy. The TIE/LN variant was rated at 150 KTU, while the TIE/sa bomber version was rated at 125 KTU.
- A dozen solar energy collectors (six on each wing panel)
- One solar energy grid monitor for each collector
- Dedicated energy accumulator lines for each collector
- An Energizer [1]
- A recharge system [1]
- A heat exchange matrix
- Six phase two energy collection coils (three on each wing attachment pylon)
- A high-pressure radioactive gas fuel tank
- An SFS I-a2b solar ionization reactor
- An SFS P-s4 twin ion engine array (comprising two engines)
- Two SFS P-w401 ion maneuvering jets (supplied by the twin ion engine array)
The squadron known as Scythe Squadron, operating TIE/LN starfighters, utilized enhanced P-w702 ion maneuvering jets to boost maneuverability within the confined spaces of the second Death Star.
Sienar eventually designed an improved iteration of this engine, named the P-s5.6 twin ion engine, for use in TIE/IN interceptors.
The SFS P-s4 engine represented an evolution of the SIE-TIE twin ion engine system, initially developed by Sienar Advanced Systems under the guidance of Raith Sienar during the later years of the Separatist Crisis. However, the underlying twin ion engine technology can be traced back to the Sith fighters employed by the ancient Sith Empire.