Dynamics and guidance of reentry spacecraft

Abstract

The diversity of reentry space missions of recent times is astonishing. Soyuz (Russian) spacecraft bring astronauts from International Space Station (ISS) to earth and land in the deserts of Kazakhstan in Central Asia. Reentry Module of Chinese Shenzhou (Divine) spacecraft, designed for human space flight, lands on the ground or in ocean. SpaceX Dragon ferries cargo between the USA and the ISS and it splashes in the Pacific Ocean, analogous to Apollo landings decades earlier but it is, remarkably, reusable. ISRO's Space Recovery Experiment splashed down in the Bay of Bengal also. ISRO is conducting flight tests of its own reusable launch vehicle. Its reentry module resembles now retired Space Shuttle which entered the atmosphere like an airplane. Cygnus (American) reentry craft is designed to transport cargo to ISS but it burns during its fiery atmospheric reentry, similar to the Automated Transfer Vehicles of European Space Agency. The present research on reentry dynamics and guidance is inspired by this multifaceted global scenario. The objectives of thesis are to develop understanding and simulation of reentry dynamics and the classic guidance laws constant drag deceleration and constant descent rate for landing. Identify the limitations of the classic guidance laws. Overcome by treating reentry as a two-point boundary value problem with initial conditions at the entry and return trajectory interface, and the final conditions as the desired landing conditions under the constraint of constant angle of attack and limits on the footprint size and touchdown velocity. This work also focuses on verifying the superiority of treating reentry problem as two-point boundary value optimisation problem with the help of two examples.