Here is a glossary of some of the terms that can be unfamiliar to the readers of the NAROM 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

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