Glossary – Andøya Space Education

Here is a glossary of some of the terms that can be unfamiliar to the readers of the Andøya Space Education student rocket pre-study.

Barycenter: the mass center of a two-body system. In a Keplerian two-body system, the barycenter is very close to the center of the heaviest object
Apogee/apogeum: farthest point away from the barycenter along the rocket/satellite orbit
Perigee/perigeum: closest point to the barycenter along the rocket/satellite orbit
Fuel: the part that burns in a propellant. In a fireplace, the fuel is the wood.
Oxidizer: the part in a propellant that releases the oxygen needed for the fuel to burn. It could be pure oxygen, but also a substance that releases an oxygen molecule during the burn
Propellant: a mix of fuel and oxidizer
Mach number: a velocity in units of the local speed of sound. Mach 4 is four times the speed of sound
Delta-v: any velocity change
Inert gas: a gas that, under certain conditions, do not easily react with another chemical substance
Unit vector: a vector of unity (1) length in direction of one of the system’s primary direction. Examples is vectors with length 1 in direction of X, Y and Z directions, and parallel and perpendicular to a plane’s velocity vector.
Launcher: in sub-orbital rocketry it is exclusively used as the mount for the rocket, usually a long rod. For the large, satellite launching rockets it has dual use: the ground segment that rockets are mounted on, as for smaller rockets, but also for the rockets itself (the launch vehicles)
S band: the RF frequency band between 2 and 4 GHz

This article is part of a pre-course program used by Andøya Space Education in Fly a Rocket! and similar programs.