Numitras

Numitras aims to be a flexible tool to plan and analyse space missions. Although an easy usage is a primary target Numitras provides a good precision. This is accomplished by the flexible plugin system that allows you to implement some parts on your own if you want to increase Numitras' accuracy.

I was inspired to this project by Orbiter, a freeware space simulator made by Martin Schweiger.

While Numitras may not yet be ready for use with that simulator (mainly because of its inability to import Orbiter scenario coordinates) it can be used for simple demonstrations, for example a Low Earth Orbit (LEO) or a a flight to the moon.

The download on this page comes with several sample configurations and body systems as demonstrated in the Quick Start tutorial (see flash window).

Download

Download Numitras (800KB)

This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 Germany License.

Features

Major features include:

• Plugins. You can code custom plugins for integrators, orbits, maneuvers and forces.
• Adaptive Integrators. It is possible to use adaptive integration methods such as Fehlberg which increases the efficiency of the simulation.
• Simulation of more than one vessel. This feature might be helpful for planning rendez-vous missions.
• Simulation of fuel consumption. You can analyse the fuel efficiency of a trajectory.
• Easy to use GUI. Including a 3D trajectory display.

Screenshots

These screenshots were taken during the development of the current version (7 June 2009):

Plugins

Numitras provides a very flexible plugin system that allows you to add custom implementations for integrators, orbits, maneuvers and forces. To do this you just have to extend the corresponding base classes. To find out how to implement plugins on your own you should have a look at the source code of the exisiting standard plugins.

Source code

The source code is available as a Zip archive. Pay attention to the Creative Commons License mentioned in the Downloads section!

To Do...

There are some features that would hugely improve Numitras' accuracy but I'm not going to continue development in the next few months. But maybe you want to try and implement them yourself:

• Simulation of atmospheric drag. Actually this would already be possible by creating a force plugin but the Vessel class hasn't got the necessary properties for this yet.
• Simulation of rotation for celestial bodies. This would enable an analysis plugin to create a ground track or to predict landing sites.
• Vessel rendez-vous and docking. This requires the simulation to be either be started at a fixed time or by a maneuver plugin. Additionally there should be various ways to define the initial state of a vessel. For example it could inherit its position and velocity from another one.
• Customized analysis features. I don't want to do all this analysis stuff. Do it yourself! Therefor I plan to create base classes which can be extended in order to analyse the trajectories in the way you need it.

If have any questions about the source code or the mathematical background of this just use the contact form.