Liquid apogee engine

A 400 N hypergolic liquid apogee engine, including heat shield and mounting structure, on display at DLR visitors center, Lampoldshausen, Germany. The engine was designed for use on Symphonie satellites. These were the first three-axis stabilised communication satellites in geostationary orbit to use a liquid bipropellant apogee engine for orbit insertion.[1]

A liquid apogee engine (LAE), or apogee engine, refers to a type of chemical rocket engine typically used as the main engine in a spacecraft.

The name apogee engine derives from the type of manoeuvre for which the engine is typically used, i.e. an in-space delta-v change made at the apogee of an elliptical orbit in order to circularise it. For geostationary satellites, this type of orbital manoeuvre is performed to transition from a geostationary transfer orbit and place the satellite on station in a circular geostationary orbit. Despite the name, an apogee engine can be used for a range of other manoeuvres, such as end-of-life deorbit,[1] Earth orbit escape, planetary orbit insertion[2][3] and planetary descent/ascent.[4]

In some parts of the space industry an LAE is also referred to as a liquid apogee motor (LAM), a liquid apogee thruster (LAT) and, depending on the propellant, a dual-mode liquid apogee thruster (DMLAT). Despite the ambiguity with respect to the use of engine and motor in these names, all use liquid propellant. An apogee kick motor (AKM) or apogee boost motor (ABM) such as the Waxwing, however, uses solid propellant.[5][unreliable source?] These solid-propellant versions are not used on new-generation satellites.[5][6]

  1. ^ a b "Unified Propulsion System - Background". Airbus Defence and Space. Archived from the original on 2014-09-25. Retrieved 29 January 2015.
  2. ^ Amos, Jonathan (2012-09-04). "Juno Jupiter probe gets British boost". BBC News. Retrieved 29 January 2015.
  3. ^ Domingue, D. L.; Russell, C. T. (19 December 2007). The MESSENGER Mission to Mercury. Springer Science & Business Media. p. 197. ISBN 978-0-387-77214-1.
  4. ^ "Industrial Policy Committee, Robotic Exploration Plan, Programme of Work 2009-2014 and relevant Procurement Plan" (PDF). European Space Agency. Archived from the original (PDF) on 2016-03-03. Retrieved 25 January 2015.
  5. ^ a b Pocha, J. J. (1987). "The Apogee Manoeuvre". Space Technology Library Volume 1. An introduction to mission design for geostationary satellites. Chapter 4: The Apogee Manoeuvre. Springer. pp. 51–66. doi:10.1007/978-94-009-3857-1_4. ISBN 978-94-010-8215-0.
  6. ^ Ley, Wilfred; Wittmann, Klaus; Hallmann, Willi, eds. (2009). Handbook of space technology. John Wiley & Sons, Ltd. pp. 323–324. ISBN 978-0-470-69739-9.