Reaction Control System

In its normal docked configuration, the USS Solstice achieves low-velocity attitude and translational control through the use of Four main and Four auxiliary reaction control engines for fine adjustments. The reaction control system (RCS) is designed primarily for sublight operations involving station-keeping, drift-mode three-axis stabilization, and space dock maneuvering.

### Layout

The RCS is divided into two parts corresponding to the two sections of the total starship. The Saucer Module RCS consists of two main and two auxiliary engines located on the hull edge; the two remaining main engines and ten venier thrusters make up the Engineering Section RCS and are located outboard of the main deflector dish, and in both Nacelles.

In the docked configuration, both systems are cross-commanded by the main computer propulsion controller (MCPC) to provide the required guidance and navigation inputs. Each main RCS engine consists of a gas-fusion reaction chamber, a magnetohydrodynamic (MHD) energy field trap, and upper and lower vectored-thrust exhaust nozzles. Deuterium fuel for each fusion chamber is stored in six immediate-use supply tanks and tied to replenish lines from the main deuterium tank group in the Engineering Section.

Fuel transfer is managed by three redundant sets of magnetic-peristaltic pumps, pressure regulators, and distribution nodes. Ignition energy for the reaction chamber is provided by a step-up plasma compression generator, and supplied through a standard capacitance tap by the ship's power distribution net.

### Construction

The reaction chamber measures 3.1 meters in diameter and is constructed of hafnium carbide 0.2 meters thick, with a 0.21 cm replaceable inner wall of duranium tritanide. It can withstand a total of 400,000 firings and 5,500 hours' operating time before requiring inner wall servicing.

A two-stage MHD field trap lies downstream from the fusion chamber. The first stage acts as an energy recovery device and returns some of the undifferentiated plasma to the power net. The second stage performs partial throttle operations, in concert with fuel flow regulators, to control the exhaust products as they enter the thrust nozzle. Both stages are manufactured as a single unit 4 x 2 x 2 meters and are constructed of tungsten bormanite. The plasma return channels are rated at 6,750 hours before the inlets must be replaced. The vectored nozzles direct the exhaust products at the proper angle for the desired force on the ship's spaceframe.

Each nozzle assembly produces a maximum of 3 million Newtons thrust with one nozzle active, and 5.5 million Newtons with both nozzles active. Kreigerium plate valves regulate the relative proportions of exhaust products flowing through the upper and lower nozzle components. Each auxiliary engine consists of a microfusion chamber and vectored-thrust nozzle, but without the MHD trap.

The microfusion chamber measures 1.5 meters in diameter and is constructed of hafnium duranide 8.5 cm thick. Each auxiliary engine channels its exhaust products through the main RCS nozzle and can generate a total thrust of 450,000 Newtons. The auxiliary engines are rated for 4,500 hours' cumulative firing time before servicing.

Also incorporated into the RCS quads are precision mooring beam tractor emitters used for close- quarters and docking maneuvers when starbase-equivalent mooring beams are not available.