The paper presents numerical results of a study concerned with the simultaneous optimization of the ascent trajectory of a two-stage launch vehicle and some significant vehicle design parameters. Besides the trajectory design, models are given that relate (i) the propulsion mass to a desirable increase in the mass flow for the rocket engines and (ii) the structural mass of the fuel tanks to a desirable increase in the propellant mass. Using these models, it is shown how the example vehicle should be modified in order to carry a higher payload into an Earth escape orbit. It is shown that an overall increase of the vehicle liftoff mass of about 4% will result in a payload increase of about 11%.
Key Words. Trajectory optimization, launch vehicles, concurrent engineering.
[1] gives an overview of a trajectory optimization software (ASTOS) which has been developed over the past ten years for the European Space Agency. This software enables a user to specify a particular launch or reentry vehicle and a particular mission solely by data. It generates an initial estimate for the solution automatically, and it assists the user in the solution process via a user interface. Among many other features, it contains a particular capability which links the vehicle design to trajectory optimization and allows the combined optimization of the trajectory and the vehicle parameters. The purpose of this paper is...
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