Table of Contents
ISRN Operations Research
Volume 2013 (2013), Article ID 498765, 9 pages
Research Article

Ascent Trajectories of Multistage Launch Vehicles: Numerical Optimization with Second-Order Conditions Verification

University “La Sapienza”, Via Salaria 851, 00138 Rome, Italy

Received 19 September 2013; Accepted 22 October 2013

Academic Editors: C. Mohan and M. Wang

Copyright © 2013 Mauro Pontani and Giampaolo Cecchetti. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Multistage launch vehicles are employed to place spacecraft and satellites in their operational orbits. Trajectory optimization of their ascending path is aimed at defining the maximum payload mass at orbit injection, for specified structural, propulsive, and aerodynamic data. This work describes and applies a method for optimizing the ascending path of the upper stage of a specified launch vehicle through satisfaction of the necessary conditions for optimality. The method at hand utilizes a recently introduced heuristic technique, that is, the particle swarm algorithm, to find the optimal ascent trajectory. This methodology is very intuitive and relatively easy to program. The second-order conditions, that is, the Clebsch-Legendre inequality and the conjugate point condition, are proven to hold, and their fulfillment enforces optimality of the solution. Availability of an optimal solution to the second order is an essential premise for the possible development of an efficient neighboring optimal guidance.