Most nontrackable orbital debris in Earth’s orbit consists of centimeter- and sub-centimeter-size objects moving at speeds of 7 − 8 km∕s. These objects represent a serious threat for spacecraft and their components. The most critical components on-board unmanned spacecraft are composite pressure vessels, as they may fail catastrophically (explode) in case of orbital debris impact, producing numerous non-trackable fragments. This may result in the loss of mission and affect and destroy other active and future spacecraft in neighbor orbits.

In the seminar, I will present the methodology that I proposed for the design of orbital debris protection systems for composite pressure vessels. According to this methodology, the vessels must be protected against highly probable impacts of small-size orbital debris through an external shielding system, and must reveal no catastrophic failure (disintegration) in the case of less probable but more damaging impacts of larger debris.

Correspondingly, I will present results of analysis of several external shielding systems for their efficiency when designed against small-size (1 mm) orbital debris impacts. The analysis included computational modeling of the shields, combining meshless (SPH) and finite element solvers, for which the predictive capabilities have been carefully validated experimentally. Through evaluations, it was possible to identify and recommend weight-efficient shielding designs.

Also, I will present a modeling procedure that was proposed to simulate behaviour of shielded composite vessels when subjected to perforating impacts by large-size orbital debris. The procedure can be used to evaluate the vulnerability of a shielded vessel to catastrophic failure. As a main part of this procedure, a meso-scale modeling approach suitable for simulating hypervelocity impact damage in filament-wound composite materials was developed and verified experimentally.