Citation: Orgeira-Crespo, P.; Rey, G.;
Ulloa, C.; Garcia-Luis, U.; Rouco, P.;
Aguado-Agelet, F. Optimization of
the Conceptual Design of a
Multistage Rocket Launcher.
Aerospace 2022, 9, 286. https://
doi.org/10.3390/aerospace9060286
Academic Editor:
Mikhail Ovchinnikov
Received: 10 March 2022
Accepted: 23 May 2022
Published: 25 May 2022
Publisher’s Note: MDPI stays neutral
with regard to jurisdictional claims in
published maps and institutional affil-
iations.
Copyright: © 2022 by the authors.
Licensee MDPI, Basel, Switzerland.
This article is an open access article
distributed under the terms and
conditions of the Creative Commons
Attribution (CC BY) license (https://
creativecommons.org/licenses/by/
4.0/).
Article
Optimization of the Conceptual Design of a Multistage
Rocket Launcher
Pedro Orgeira-Crespo
1,
* , Guillermo Rey
1
, Carlos Ulloa
1
, Uxia Garcia-Luis
1
, Pablo Rouco
1
and Fernando Aguado-Agelet
2
1
Department of Mechanical Engineering, Heat Engines and Machines and Fluids, Aerospace Engineering
School, University of Vigo, Campus Orense, 32004 Orense, Spain; guillermo.rey@uvigo.es (G.R.);
carlos.ulloa@uvigo.es (C.U.); uxia.garcia.luis@uvigo.es (U.G.-L.); pablo.rouco@uvigo.es (P.R.)
2
Telecommunication Engineering School, University of Vigo, 36310 Vigo, Spain; faguado@uvigo.es
* Correspondence: porgeira@uvigo.es
Abstract:
The design of a vehicle launch comprises many factors, including the optimization of the
climb path and the distribution of the mass in stages. The optimization process has been addressed
historically from different points of view, using proprietary software solutions to obtain an ideal
mass distribution among stages. In this research, we propose software for the separate optimization
of the trajectory of a launch rocket, maximizing the payload weight and the global design, while
varying the power plant selection. The launch is mathematically modeled considering its propulsive,
gravitational, and aerodynamical aspects. The ascent trajectory is optimized by discretizing the
trajectory using structural and physical constraints, and the design accounts for the mass and power
plant of each stage. The optimization algorithm is checked against various real rockets and other
modeling algorithms, obtaining differences of up to 9%.
Keywords: rocket motor simulation; trajectory optimization; design optimization
1. Introduction and State of the Art
Since the beginning of the space age, in 1957, access to space has become widespread.
Although in 1966, only the USA, France, and the USSR had the capacity to send satellites
into space using their own launch vehicles, today, the list of countries with such capacity
has increased, including those involved in the Europe’s space agency, China, Iran, Ukraine,
India, Israel, North Korea, Brazil, Japan, and New Zealand [
1
]. Manned missions have also
received significant interest from both governments and the private sector: both world
powers, such as China or the USA, have shown interest in taking human beings to new
frontiers such as the Moon or Mars, and private companies, such as Virgin, SpaceX, or Blue
Origin, are offering commercial flights around the Earth.
A rocket or launch vehicle carries a payload beyond Earth’s atmosphere, powered
by a jet rocket engine. Depending on the mass of the vehicle, they can be classified in the
following categories, shown in Table 1 [2]:
Table 1. Classification of launch vehicles according to its mass.
Category Mass (t)
Small 0–2
Midsize 2–20
Heavy 20–50
Super heavy >50
To increase launch efficiency and reduce costs, the following alternatives have histori-
cally been addressed:
Aerospace 2022, 9, 286. https://doi.org/10.3390/aerospace9060286 https://www.mdpi.com/journal/aerospace
