Glossary

Burn

"To burn" is a colloquial term used to describing use of a rocket.

Interlunar

Travel between natural satellites of the planet or between a planet and its satellites.

Overcooling a reactor

If the thermal power demands of a spaceship exceed the capacity of the reactor, it's internal temperature can fall and degrade the operation. Symptoms of overcooling include:

 * Loss of thrust due to insignificantly heated propellant.
 * Electrical power shortages due to insufficient heat and pressure provided to power plant.

Overheating

All reactors are equipped with mechanisms to regulate the temperature to prevent both overheating and overcooling and in normal operation excessive temperature is not a risk. Damaged reactor may however lag behind, causing temperature to fall or rise above rated operating threshold.

Excessive temperature poses a great risk to the spaceship. Symptoms of overheat include:

 * With low overheat risk of turbine galling.
 * With moderate overheat risk of explosive reactor decompression.
 * With severe overheat risk of meltdown.

Methods of preventing overheat:

 * Maintaining fuel rod actuators in proper working order.
 * Venting excessive remass with simultaneous RCS burns.

Propellant

Reactive Mass, propellant, or remass, is what enables ships to move. Moving in space is really hard, almost the only way to do it is to eject something in opposite direction. The faster the exhaust velocity of your engines the less propellant you need to maintain same acceleration.

Propellant economy

Fissile fuel of a Nuclear Thermal Rocket can last months to years, so the only factor that limits mission time is the amount of propellant and propellant economy.

The propellant economy measures how much propellant the rockets uses for a burn. It's usually measured by __kg/s__ or __g/s__ for smaller thrusters. Better (smaller) propellant economy will allow longer missions on the same Propellant Tank.

The propellant economy is improved by:

 * Higher exhaust velocity and specific impulse inherent to the rocket.
 * Lower thrust.

The propellant economy is degraded by:

 * Lower exhaust velocity and specific impulse inherent to the rocket.
 * Higher thrust.

Most thermal rockets in the rings use water as a reactive mass, due to it's abundance in the Saturn system.

Propellant tank

Modern ships can be retro-fitted with various sizes of Propellant Tank , ranging from close-range to interplanetary-capable.

Increasing the size of your tank will prolong your available ringdive time, but at the same time the added mass will make the ship less maneuverable.

Railgun

Railguns are simple mass accelerators requiring physical contact of the projectile with guiding rails. Projectile closes the electric circuit and induces electromagnetic force that propels it. Compared to more complex coilguns, railguns are relatively simple devices capable of delivering impressive rate of fire, but they lose a lot of efficiency due to friction of the projectile and are prone to malfunctions.

Railguns require kinetic ammunition storage to function.

Reaction Control System

RCS thrusters are the main method of propulsion during ringdives. A set of relatively small engines positioned in key location of a spaceship can be used to precisely control movement and orientation of the craft.

Modern spaceships utilize either nuclear thermal, magnetoplasmadynamic, ion or hybrid thrusters as their RCS. Tiny craft will usually utilize cold gas thrusters.

Nuclear reactor

The reactor is a core power-plant of any codex:spaceship, providing it with both thermal and codex:electrical power.

Both codex:fission and codex:fusion reactors provide heat directly, through the respective nuclear reaction. Production of the codex:electrical power from the supplied heat is performed by codex:turbines, codex:magnetoplasmadynamic genrators or codex:thermoelectric generators in small crafts.

Exhaust of a codex:nuclear thermal rocket will cool down the reactor with every codex:burn, and waste heat is disposed with codex:radiators.

Ringdive

A colloquial term for a excavation mission in the Rings of Saturn.

Ringroids

Ringroids is the colloquial name of particles forming the Rings. Composed mostly of water ice, they range in sizes from grains of dust to huge moonlets.

Structure of a ringroid will range from ball of ice to loosely-packed snow and effect of impact is not predictable. Ringroids in the A Ring are know to contain unusually high concentration of ore chunks.

Skyscraper layout

A "skyscraper layout" of a codex:spaceship takes into account the apparent codex:artificial gravity of an codex:interlunar codex:burn.

Ships utilizing skyscraper layout will have decks aligned paralel to the engine-tip axis of the ship. When ship codex:burns forward, the apparent "up" will be along the direction of acceleration.

In usual codex:interlunar travel ship will codex:burn to accelerate half of the way, flip and codex:burn to deccelerate the other half, providing near constant codex:artificial gravity to the crew.

Space Station

A permanent orbital habitat, designed for prolonged occupation.

Spaceship

Spaceship is an umbrella term to describe any codex:spaceworthy vehicle capable of at least codex:interlunar travel.

Spaceworthy

Able to provide crew safety in space travel.

Specific impulse

Specific impulse (I_sp) of a rocket determines it's codex:propellant economy. The higher the specific impulse the less propellant will your rocket consume to provide same acceleration - it will however need much more power, both thermal and electric to maintain the codex:burn.

The exhaust velocity usually measured in __s__.

Exhaust velocity is directly proportional to codex:exhaust velocity and the terms are used interchangeably.

The rings

Most prevalent ring system of the Sol, rings contain codex:ringroids with mass equivalent of small moon. With thickness ranging from dozens meters to few kilometers, rings span enormous surface area and are valued resource of rare earth minerals discovered during codex:asteroid impact of 2184.

Thermal power

Thermal power is produced by codex:spaceship's nuclear codex:reactor directly through codex:fission or codex:fusion. Heat is usually consumed by codex:RCS thrusters, codex:main engine to propel the craft.

If propulsion power consumption will exceed your reactor heat output, spaceship risks codex:overcooling the reactor.

Thrust

Thrust is the measure of propulsive power of the rocket. The higher the thrust the more acceleration will the rocket provide to a codex:spaceship of same mass.

Thrust is measured in kN.

Higher thrust will demand more thermal and codex:electrical power from the codex:reactor. The power requirements can be negated by decreasing codex:specific impulse and codex:exhaust velocity at cost of degraded codex:propellant economy.

Turbine

Electrical turbine is a common power plant used by codex:spaceships.

Simple and reliable, it uses pressurized codex:supercritical codex:propellant directly from codex:reactor core to produce codex:electrical power. The propellant is vented in an codex:open cycle cooling.

While turbines provide relatively low power output, they are reliable and don't require any initial power to operate.

Excessive temperature of the codex:reactor can damage the turbine.