Tag Archives: orbiter

2015-12-02: Orbiter

I have purchased and flown flight simulators of various types for many years. They are a reasonable substitute for actually piloting a Cessna or Schweitzer.

Several years ago, I found the Orbiter space flight simulator. This is of similar complexity to the commercial flight simulators I’ve tried, but free to play and developed by one man: Dr. Martin Schweiger, a computer science researcher at University College London. Dr. Schweiger (or martins, as he’s known on the Orbiter Forum) retains control of the source code of the core program, but has published interfaces for use of its facilities by add-ons developed by others.

A robust community of users and developers has grown up around the program, using the Orbiter Forum for exchange of news and analysis of issues, and answering the questions of newcomers to this complicated topic. In addition, the community maintains (sporadically) the OrbiterWiki for longer-term articles.

I have ambitions to fly some of the highly realistic spacecraft add-ons (NASSP and Space Shuttle Ultra), as well as some of the science fiction add-ons (Firefly and World of 2001). I’d also like to develop scenarios for certain types of missions, and develop add-on ships to support Two Years At The Hot End. I also think more could be done on the educational side, and have initiated a section of pages on OrbiterWiki under the umbrella title Rocket Science For Amateurs. I hope to expand my own and others’ contributions to that.

Now that I have a mostly-reliable Windows 10 installation (dual boot via Bootcamp on a MacBook Pro), I can restart some of my Orbiter tasks:

  • Appointment in the rings – two DGs, polar and equatorial orbits intersecting in the Cassini gap
  • Appointment with rocks –  same as above, but with a cloud of rocks/asteroids around one or both DGs
  • NASSP Apollo 7
  • NASSP Apollo 12 (when available)
  • Figure out how to make Orb::Connect::Web work in Windows 10, and develop phone/tablet-based panels
  • Firefly/Serenity
  • Asteroid mining
  • RSFA – other articles by Keithth G


  • 2015-12-02: started.
  • 2016-02-15: Added Keithth G’s symplectic integrator article to RSFA on Orbiter-Wiki

2015-11-28: Rocket Science For Amateurs

I’ve been fiddling with the Orbiter space flight simulator since early 2009. One of the interesting features is its community of users on the Orbiter Forum. The veterans are very welcoming to newbies, and constantly helpful in solving problems. They also analyze recent space-related events and proposals. Several members expend large efforts in developing add-ons to enhance the Orbiter experience, particularly the developer of Orbiter itself, Dr. Martin Schweiger.

Among the contributions is a book, Go Play In Space (GPIS), written by Bruce Irving with help from a couple of others. For several years, newbies have been urged to read this book for a gentle introduction to Orbiter. A second edition of the book was written for the 2006 version of Orbiter. When the 2010 version was released, I heard that Bruce was planning a new revision. I volunteered to help edit the new version, to test updated scenarios, and otherwise try to be helpful without actually having enough expertise to make primary contributions. Bruce and Mark Paton accepted my help, and we updated about six of the ten chapters. However, the process was slow, with everyone having other commitments, and eventually petered out.

It occurred to me that it would be simpler to switch from a book-oriented approach for GPIS to a wiki-like approach. This would allow updates to be made incrementally, and by multiple contributors. The analog is the “release early, release often” approach to tech startups. I was also aware of some other out-dated Orbiter-related documentation that might benefit from this approach. I conceived the idea of an umbrella website that would include this type of reference documentation, and thought of calling it Rocket Science For Amateurs (RSFA). I contacted the relevant authors and obtained permission and encouragement to proceed, and actually set up a MediaWiki website for the purpose.

The administrative overhead of running the site proved too burdensome. However, OrbiterWiki is another Orbiter-related website. It seemed easier to move the RSFA material there. The main difficulty was restrictions on the types and size of files that can be stored on Orbiter Wiki. I was able to reach the administrator, and made a pitch for RSFA. He (or she; user names are ambiguous) made the necessary changes, and I moved the latest versions of GPIS and the IMFD Full Manual to OrbiterWiki. I announced it on Orbiter Forum on 2015-01-02. Since the announcement, I added an index to a set of YouTube tutorials and demonstrations.

There has been little response so far (over a year on). I have ideas for additional topics to add, reposting (with permission) some orbital dynamics articles by another Orbinaut.


  • 2015-11-28: in-progress – three topic areas ready for use (out of a dozen or so possible)
  • 2016-02-14: Added article on a Simplectic Integrator (by Keithth G)
  • 2017-03-12: Discovered that several articles by Keithth G on Orbiter Forum, which would have made good material for RSFA, have been deleted; no reasons have been given, but someone speculated that his employer might have viewed the material as their intellectual property.