An accurate and efficient core layer for space flight dynamics applications

Orekit 12.0.2 released, get it!

What is it?

Orekit, a low level space dynamics library written in Java, has gained widespread recognition since it was released under an open source license in 2008.

Space dynamics library

Orekit aims at providing accurate and efficient low level components for the development of flight dynamics applications. It is designed to be easily used in very different contexts, from quick studies up to critical operations.

As a library, Orekit provides basic elements (orbits, dates, attitude, frames…) and various algorithms to handle them (conversions, propagations, pointing…).

Java & Python APIs

Orekit is developed in Java. As Python is widely used in the scientific world, one of our awesome contributors has created and maintains a Python wrapper. Choose your side and enjoy!

Free (open source) software

Orekit is freely available both in source and binary formats, with all related documentation and tests.

Orekit is distributed under the Apache License version 2.0, a well known business-friendly license. This means anybody can use it to build any application, free or not. There are no strings attached to user code.

Who is using it?

  • CS GROUP develops OreFLIDS (Orekit Flight Dynamics System), a complete off-the-shelf flight dynamics system (FDS) adapted to NewSpace and huge constellations.

  • Airbus Defence and Space (ADS) uses Orekit in Quartz, its new generation flight dynamics software. In addition, ADS actively contributes to Orekit and is member of its Project Management Committee (PMC).

  • Orekit is used for various studies by the U.S. Naval Research Laboratory (NRL). In addition, the NRL actively contributes to Orekit and is member of its PMC.

  • Swedish Space Corporation (SSC) uses Orekit for various studies. SSC has created and maintains the Orekit Python wrapper for years. SSC is member of Orekit PMC.

  • Thales Alenia Space uses Orekit for the flight dynamics software of its new geostationary electric platform SpaceBus Neo (within ESA's NEOSAT program) and is member of its PMC.

  • Orekit has been successfully used during the real time monitoring of the rendez-vous phase between the Automated Transfer Vehicle (ATV) and the International Space Station (ISS) by the Centre National d'Études Spatiales (CNES) and the European Space Agency (ESA).

  • Orekit is used for several studies and ground systems developments by various industrial actors such as EUMETSAT.

  • Exotrail uses Orekit as a low-level astrodynamics layer for its mission analysis and constellation design software spacestudioTM, and its constellation operation software spacetowerTM.

  • You may discover other usages of Orekit in the presentations made by several space sector actors during the Orekit Day 2017 and Orekit Day 2019.

Who is behind it?


Orekit has been in development since 2002 inside CS GROUP and is still used and maintained by its space dynamics experts. Several major actors of space research and industry are now involved into this project.

This project follows the Free and Open Source Software (FOSS) development best practices identified by the Core Infrastructure Initiative:

Core Infrastructure Initiative (CII) badge

We do our best to provide you with a quality code:

quality gate status code coverage status

Open governance

The Orekit project is driven according to an open governance model, involving representatives from different space field actors in a Project Management Committee (PMC).

PMC members

  • Anne-Olivia Biramben (CS GROUP)
  • Bryan Cazabonne (Airbus Defence and Space)
  • Paul Cefola (University at Buffalo)
  • Frank Dreger (European Space Agency)
  • Hank Grabowski (independent expert)
  • Sébastien Herbinière (independent expert)
  • Petrus Hyvönen (Swedish Space Corporation)
  • Yannick Jeandroz (Airbus Defence and Space)
  • Maxime Journot (CS GROUP)
  • Christophe Le Bris (Thales Alenia Space)
  • Stéphanie Lizy-Destrez (ISAE)
  • Luc Maisonobe (Thales Alenia Space)
  • Guillermo Ortega (European Space Agency)
  • Pascal Parraud (CS GROUP)
  • Romain Serra (Exotrail)
  • Evan Ward (U.S. Naval Research Laboratory)