This is a list of terms used in both this Wiki and in real-life.
Terms[]
| Term | Definition |
|---|---|
| Apoapsis | An object's furthest point from a body in an orbit |
| Periapsis | An object's closest point from a body in an orbit |
| Aerobrake | The act of slowing down a spacecraft via atmospheric friction |
| Drag | Force acting opposite to any object's relative motion |
| Eccentricity | How much an object's orbit deviates from a circle (0.0 = circular; Between 0.0 and 1.0 = Ellipse; 1.0 = Parabola; More than 1.0 = Hyperbola ) |
| Gravity assist | Entering a sphere of influence without orbiting to accelerate/decelerate and reduce fuel usage |
| Liftoff | The first moment of a rocket's flight |
| Lithobrake | Slow down and safely land a spacecraft by impacting into a celestial body |
| Oberth effect | Burn at periapsis during repeated orbits to save Delta-v |
| Trajectory | The path that an object follows |
| Thrust | Reaction force described quantitatively by Newton's third law |
| Escape velocity | Minimum speed for an object to escape from a body's Sphere of Influence |
| Suicide Burn | Landing burn at 100% thrust shortly before landing. |
| Prograde | Burn in the direction of the orbit |
| Retrograde | Burn in the opposite direction of the orbit. |
| Semi-major axis | An imaginary line between an ellipse's centre and the furthest point from it on its perimeter |
| Revolution | The time it takes for an object to complete a full orbit around another object. |
| Rotation period | The time it takes for an object to rotate around its rotational axis until it reaches the same relative position to the surrounding objects as before. |
| Inclination | The angle the rotational axis is shifted from the objects relative position to its surroundings. |
| Cosine decay | The inefficiency caused by engines deviating from the direction of thrust, equal to 1 minus the cosine of the deviation. |
Abbreviations[]
| Abbreviation | Full Form |
|---|---|
| Delta-v (∆v) | Change in velocity that can be made by the spacecraft |
| g | Gravitational constant of Earth |
| ICBM | Intercontinental Ballistic Missile. |
| LEO | Low Earth Orbit |
| LES | Launch Escape System |
| RCS | Reaction Control System |
| SOI | Sphere of Influence |
| SRB | Solid Rocket Booster |
| SSTO | Single Stage To Orbit |
| TWR | Thrust to Weight Ratio |
| RTG | Radioisotope Thermoelectric Generator |
| LRB | Liquid Rocket Booster |