J.4.3                    Statistical analysis

A statistical tool, ESABASE2/DEBRIS, was developed for a detailed impact risk assessment of smaller, non­trackable particles [RD.30]. ESABASE2/DEBRIS is a fully three dimensional numerical analysis tool including directional and geometrical effects and spacecraft shielding considerations. It is based on environment and particle/wall interaction models and includes several meteoroid and space debris flux models.

The user specifies the mission, spacecraft geometry, attitude and shielding as well as the particle type, size and velocity range to be analysed. The computed output includes:

•                the number of impacts;

•                the resulting number of damaging impacts taking into account the spacecraft shielding and damage assessment equations;

•                the mean particle impact velocity (amplitude and direction);

•                the numbers of craters of specified size;

•                the probability of no failure.

ESABASE2/DEBRIS is applicable for earth orbits and allows the optional use of several meteoroid and debris flux models. The tool includes the MASTER-2005 model and the sporadic and stream meteoroid models given in 10.2.4, including the altitude dependent velocity distribution.