  In the past few years, the interest towards the implementation of
design-for-demise measures has increased steadily. Most mid-sized satellites
currently launched and already in orbit fail to comply with the casualty risk
threshold of 0.0001. Therefore, satellites manufacturers and mission operators
need to perform a disposal through a controlled re-entry, which has a higher
cost and increased complexity. Through the design-for-demise paradigm, this
additional cost and complexity can be removed as the spacecraft is directly
compliant with the casualty risk regulations. However, building a spacecraft
such that most of its parts will demise may lead to designs that are more
vulnerable to space debris impacts, thus compromising the reliability of the
mission. In fact, the requirements connected to the demisability and the
survivability are in general competing. Given this competing nature, trade-off
solutions can be found, which favour the implementation of design-for-demise
measures while still maintaining the spacecraft resilient to space debris
impacts. A multi-objective optimisation framework has been developed by the
authors in previous works. The framework's objective is to find preliminary
design solutions considering the competing nature of the demisability and the
survivability of a spacecraft since the early stages of the mission design. In
this way, a more integrated design can be achieved. The present work focuses on
the improvement of the multi-objective optimisation framework by including
constraints. The paper shows the application of the constrained optimisation to
two relevant examples: the optimisation of a tank assembly and the optimisation
of a typical satellite configuration.
