Re-entry mission design remains an active field of study to safely return space missions back to Earth. With the developments in on-board computers, mission design and especially optimization of these missions has been performed numerically at an increasing rate at the cost of computing power. Analytical second-order methods have previously been shown to provide accurate results for mission design with less computational effort, but have not been applied to mission optimization. The analytical method was tested and shown to provide good results for a range of initial conditions. During optimization, restrictions arising from their derivation show that fundamental problems remain for application in mission optimization as the entry state cannot be freely defined. Additionally, two new optimization algorithms have been tested for re-entry mission optimization, a variable chromosome length algorithm and the Multi-objective Hypervolume-based Ant Colony Optimizer, both are found to provide results similar to the MOEA/D algorithm.

The purpose of this analysis is to present the design of the complete mission involving a dual spacecraft configuration that will analyse the rings of Saturn. The two spacecraft are an orbiter that will orbit at 142,000 km from the centre of Saturn, and a hovercraft that will hover at a distance of 2-3 km fromSaturn its rings...