Spacecraft bus design and sizing

This work forms part of the lecture material for a 1st year BSc course on aerospace design (AE1222-II) at TU-Delft/faculty of Aerospace Engineering. This document deals specifically with the design of spacecraft and more in particular the bus or the carrier vehicle and presents the general approach and methods used in conceptual spacecraft vehicle design in the period from 2010 till present (June 2025). The basic method is structured along 7 steps that represent general steps in solving a (design) problem and includes 1) problem definition, 2) establishment of requirements, 3) setting up design options, 4) analyzing design options, 5) comparing design options, 6) trading design options and selecting the best option, and 7) evaluating and if necessary iterating on the design. In this document all these steps are described in some detail. Focus is on analysis methods used in conceptual design of a spacecraft with attention to subsystem design. Subsystems dealt with include structures, thermal, propulsion, communications, command and data handling and electrical power.