Table of Contents ECSS Model Page
Background Information Table of Contents
Model packages

SPENVIS is a WWW-based instrument intended to facilitate the use of models of the spatial environment in a consistent and structured way. The system breaks down into a number of model packages, which are briefly described below:

Coordinate generators

Most of the models implemented in SPENVIS require as input a set of point on a spacecraft trajectory or a user-defined set of geographic points. These sets of points are produced by two tools: the orbit generator and the coordinate grid generator. In general, one of these tools has to be used before the models themselves can be accessed. SPENVIS Is able to detect whether a spacecraft trajectory or a coordinate grid has been generated: if this is not the case, the system will issue an error message and prompt the user to run the orbit or coordinate grid tool, after which the model in question can be run. In addition, the model menu on the packages page will adapt automatically to the selection of trajectories or grids.

For advanced users, a third option allows to switch to another planet. See Planetary environment below.

Once a trajectory or a coordinate grid has been generated, it can be used by different models. This means that, in the context of a given project, it is not necessary to generate coordinates for each model separately.

Warning! When running the orbit or grid generator, all outputs previously obtained with models that use the respective coordinate tool, are deleted. This is to ensure consistency between results, and to avoid errors in the plotting routines that produce the graphical output. The input parameters for the models are not deleted, so that they can be run again in the same way.

Radiation sources and effects

If the currently selected coordinate system is a grid, trapped particle models can be evaluated and visualised over the grid. In addition, these models can be run over a grid of magnetic coordinates from the miscellaneous model menu.

For a spacecraft trajectory, a suite of radiation source and effects models is available:

The combined run feature allows the selection of a number of models for a consecutive run without navigation between models. This feature facilitates investigating the influence of orbital or radiation model parameters on the radiation effects. This feature is available for advanced users only.

Spacecraft charging

SPENVIS Incorporates a number of utilities developed for ESA/ESTEC to solve various problems associated with spacecraft/plasma interactions.

The DICTAT programme calculates the electron current that passes through a conductive shield and becomes deposited inside a dielectric. From the deposited current, the maximum electric field within the dielectric is found. This field is compared with the breakdown field for that dielectric to see if the material is at risk of an electrostatic discharge.

Three modules of the programme suite ESPIRE have been implemented in SPENVIS:

In addition, a collection of satellite data of charging events is available from the GORIZONT/ADIPE and CRRES/LEPA missions.

Atmosphere and ionosphere

SPENVIS implements a number of reference atmosphere and ionosphere models in two applications:

Magnetic field

SPENVIS implements some of the most currently used magnetic field models in three applications:

Meteoroids and debris

The following models are being included in SPENVIS: NASA90 and MASTER for orbital debris, the Grün meteoroid model, and wall penetration models.

Both natural meteoroids and man-made space debris particles represent a serious hazard to space vehicles in orbit around the Earth. Nearly all meteoroids originate from comets or asteroids, and are generally distributed isotropically (termed `sporadic' meteors), except those that retain their parent body orbit, which are termed `meteor streams'. The total meteoroid environment is thus comprised of the average of the sporadic meteors together with the yearly average of meteor streams. Also co-existent with the natural particle flux are space debris particles, most of which are in high-inclination orbits, and consist of spent rocket stages, inactive payloads, debris from exploded satellites, etc.

The meteoroid and debris models included in SPENVIS are:

For the particle/wall interaction two models are included in SPENVIS that are based on:


This package includes a number of models and tools that are not covered by the other packages:

Geant4 tools

This package includes a number of models and tools that are using the Geant4 toolkit:

ECSS Space Environment Standard

The SPENVIS system contains a copy of the European Cooperation for Space Standardization (ECSS) standard on space environment. The official site is maintained by ESTEC.

Links are available from the help pages to the relevant ECSS standards, and from the ECSS pages to the SPENVIS model and help pages.

Planetary environment

SPENVIS includes models related to the space environment of other planets: In order to access those models, the user has first to switch to another planet in the coordinate generator package.

Last update: Fri, 20 Apr 2018