Reaction engine

From Kerbal Space Program Wiki
Revision as of 15:04, 10 June 2013 by Ruedii (talk | contribs) (Disadvantages of Solid Fuel Rocket Engines: --Monolithic Design)
Jump to: navigation, search
This article is a stub. You can help KSP Wiki by expanding it.

A rocket engine is an engine that uses nothing but its onboard propellant to generate thrust. Unlike traditional air breathing engines used by atmospheric crafts rocket engines are able to function in a vacuum where no oxygen is present.

History

Rocket engines were present in KSP in all public releases of the game.

Approaches to Rocket Engines

Rocket engines come in two commonly used forms. The first and most ancient type is a solid fuel rocket which is as simple as igniting a solid, self-oxidizing compound within the casing of the rocket and allowing the escaping gases to be released through a nozzle at the rear.

Liquid fuel engines are powered by a liquid propellant which is usually comprised of two separate fuels which are combined and ignited, typically liquid hydrogen and liquid oxygen or liquid kerosene, and liquid oxygen. In KSP there are two different types of liquid rocket engines; aerospike and bell type liquid rocket engines.

Advantages of Solid Fuel Rocket Engines

  • Has a very high thrust to weight ratio
  • Engine and fuel tank are the same part, lowering parts count

Disadvantages of Solid Fuel Rocket Engines

  • Monolithic design. Must be built in one piece.
  • Cannot be throttled or switched off after ignition
  • Once spent, they are unable to use fuel from another source of the craft

Advantages of Liquid Fuel Rocket Engines

  • Can use fuel stored elsewhere on the craft
  • Throttle can be adjusted depending on thrust requirements
  • Can be switched off and re-ignited at will
  • Many nozzles can be gimballed for thrust vectoring

Disadvantages of Liquid Fuel Rocket Engines

  • Lower power to weight ratio compared to Solid rocket engines
  • Complex design with fuel tanks and fuel lines
  • Efficiency largely dependent on design, with large variations.