  The space environment around the Earth is populated by more than 130 million
objects of 1 mm in size and larger, and future predictions shows that this
amount is destined to increase, even if mitigation measures are implemented at
a far better rate than today. These objects can hit and damage a spacecraft or
its components. It is thus necessary to assess the risk level for a satellite
during its mission lifetime. Few software packages perform this analysis, and
most of them employ time-consuming ray-tracing methodology, where particles are
randomly sampled from relevant distributions. In addition, they tend not to
consider the risk associated with the secondary debris clouds. The paper
presents the development of a vulnerability assessment model, which relies on a
fully statistical procedure: the debris fluxes are directly used combining them
with the concept of the vulnerable zone, avoiding the random sampling the
debris fluxes. A novel methodology is presented to predict damage to internal
components. It models the interaction between the components and the secondary
debris cloud through basic geometric operations, considering mutual shielding
and shadowing between internal components. The methodologies are tested against
state-of-the-art software for relevant test cases, comparing results on
external structures and internal components.
