Impulse Boosters

Impulse Boosters are the sub-light propulsion systems that let a starship steer, maneuver, and cross planetary distances. They are also the engines responsible for escaping and reentering atmospheres, which is why every impulse booster is built as a hybrid fusion rocket engine — capable of both atmospheric thrust and vacuum flight.

In the world of Black Horizon there are generally two families of engines related to space travel: Impulse Boosters and Horizon Drives. Impulse Boosters are used for moving within atmospheres and between planetary bodies; Horizon Drives are FTL drives used to travel between stars.

Impulse Boosters produce controlled fusion detonations in a rotational array that evens out to a steady thrust. A magnetic coil is wrapped around the engine to launch the resulting fusion plasma out of the nozzle.

At the heart of every Impulse Booster is a Rotation Detonation Engine (RDE) — a rotating detonation front sustained around an aerospike nozzle. Rather than a continuous burn, the RDE fires in controlled pulses of energetic reactions, giving thrust or boost — which is where the name Impulse Booster comes from.

Flow

• Liquid Oxygen is pumped from the oxidizer tank down into the main combustion chamber to seed the initial detonations.
• Liquid Hydrogen, in the form of Theronium, is pumped down along the rocket nozzle. There it cools the aerospike and preheats the fuel before combustion.
• The Detonation Spark Igniter (DSI) kicks off the reaction between the hydrogen and the oxidizer. Once running, the rotating detonation front sustains itself around the aerospike.

The fuel of choice is Theronium — a nanofluid of liquid hydrogen laced with nanoparticles known as EMTraps (Electro Magnetic Traps).

Each EMTrap is a nanoscale electromagnetic cage that suspends a single anti-hydrogen atom — an antiproton with a positron around it. Antimatter cannot be stored by conventional means, since it annihilates on contact with matter, so the EMTrap is what makes Theronium possible in the first place.

When Theronium detonates in the combustion chamber, the hydrogen ignites in the RDE cycle and the EMTrap shielding evaporates, releasing the anti-hydrogen for a secondary antimatter reaction. Even at only a few hundred grams of antimatter per tonne of fuel, this dramatically multiplies the yield — and is the basis of every Impulse Booster's efficiency and range.