RocketPy: Six Degree-of-Freedom Rocket Trajectory Simulator
Publication: Journal of Aerospace Engineering
Volume 34, Issue 6
Abstract
RocketPy is a new open-source Python library specialized in trajectory simulations of sounding rockets and high-powered rockets. Having a modular structure and being built on top of a six degree-of-freedom flight dynamics model that includes detailed mass variation effects, RocketPy allows for accurate trajectory prediction of different rocket configurations. Additionally, weather data from several meteorological agencies, such as reanalysis, forecasts, and ensembles, are an innovative feature directly integrated into the library, providing precise information about atmospheric conditions for each simulation. The software was successfully validated for three rockets developed by different universities, with apogee predictions showing deviations of the order of 1% when compared to actual flight data. Furthermore, due to its modular nature, RocketPy can be easily employed in optimization studies and Monte Carlo analyses. The latter was a key aspect of this work, enabling the calculation of landing dispersion ellipses based on input uncertainties. Since running several Monte Carlo analyses is computationally expensive, a new algorithm was proposed to significantly speed up results based on rejection sampling. The code described here and made available online enhances the state of the art represented by several widely used software and can serve as a framework for future research on rocket dynamics, control, flight optimization, and dispersion analysis.
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Data Availability Statement
Some or all data, models, or code generated or used during the study are available in an online repository, which can be accessed at https://doi.org/10.5281/zenodo.4279966 (Alves et al. 2020), in accordance with funder data retention policies.
The repository holds both the flight data for the experimental rocket missions used in this work (Valetudo, Bella Lui Kaltbrunn, and NDRT vehicle) and the corresponding simulation code, including necessary input files, presented in Fig. 5 and in Table 3. Furthermore, all models, code, and data used for the comparison with previous works presented in Fig. 4 and in Table 2 are also included. The Monte Carlo dispersion analysis model and output data are also available, along with the code necessary to generate Fig. 7. Finally, the repository also contains the full implementation of the Multivariate Rejection Sampling algorithm and its application, as shown in Fig. 8.
Acknowledgments
The authors of this work would like to thank the Notre Dame Rocket Team and the École Polytechnique Fédérale de Lausanne Rocket Team for granting access to their data. Moreover, the authors are also thankful for Escola Politécnica of the University of São Paulo, for the opportunity to develop the current publication, and also grateful to all the members of Projeto Jupiter that contributed towards making RocketPy the current robust software. Finally, the members of Projeto Jupiter are especially thankful for the financial aid provided by Amigos da Poli (ADP), whose support is invaluable for the team and consequently for the present paper. BSC also acknowledges financial support from the Brazilian National Council for Scientific and Technological Development (CNPq) in the form of productivity grant (Grant No. 312951/2018-3).
References
Aitoumeziane, A., et al. 2019. Traveler IV apogee analysis. Los Angeles: USC Rocket Propulsion Laboratory.
Alves, G. F., G. H. Ceotto, R. N. Schmitt, and L. A. Pezente. 2020. “Projeto-Jupiter/RocketPaper.” Accessed November 21, 2020. <https://doi.org/10.5281/zenodo.4279966>(11).
Apogee Rockets. 2020. “RockSim information.” Accessed December 5, 2020. https://www.apogeerockets.com/RockSim/.
Astos Solutions GmbH. 2018. “ASTOS—Analysis, simulation and trajectory optimization software for space applications.” Accessed November 25, 2020. https://www.astos.de/products/astos.
Barrowman, J. S. 1967. “The practical calculation of the aerodynamic characteristics of slender finned vehicles.” Ph.D. thesis, Dept. of Aerospace Engineering, Catholic Univ. of America.
Box, S., C. M. Bishop, and H. Hunt. 2011. “Stochastic six-degree-of-freedom flight simulator for passively controlled high-power rockets.” J. Aerosp. Eng. 24 (1): 31–45. https://doi.org/10.1061/(ASCE)AS.1943-5525.0000051.
Casella, G., C. P. Robert, and M. T. Wells. 2004. Vol. 45 of Generalized accept-reject sampling schemes. Notes-monograph series, 342–347. Durham, NC: Institute of Mathematical Statistics.
Chew, V. 1966. “Confidence, prediction, and tolerance regions for the multivariate normal distribution.” J. Am. Stat. Assoc. 61 (315): 605–617. https://doi.org/10.1080/01621459.1966.10480892.
Da Silveira, G., and V. Carrara. 2015. “A six degrees-of-freedom flight dynamics simulation tool of launch vehicles.” J. Aerosp. Technol. Manage. 7 (2): 231–239. https://doi.org/10.5028/jatm.v7i2.433.
Eerland, W. J., S. Box, and A. Sóbester. 2017. “Cambridge rocketry simulator—A stochastic six-degrees-of-freedom rocket flight simulator.” J. Open Res. Software 5 (1): 1–5. https://doi.org/10.5334/jors.137.
Eke, F. O., and T. C. Mao. 2002. “On the dynamics of variable mass systems.” Int. J. Mech. Eng. Educ. 30 (2): 123–137. https://doi.org/10.7227/IJMEE.30.2.4.
Harris, C. R., et al. 2020. “Array programming with NumPy.” Accessed November 2, 2020. https://doi.org/10.1038/s41586-020-2649-2%3E(9).
Hindmarsh, A. 1992. ODEPACK. A collection of ODE system solvers. Livermore, CA: Lawrence Livermore National Lab.
ISO Central Secretary. 1975. Standard atmosphere. Geneva: ISO.
Kluyver, T., et al. 2016. “Jupyter Notebooks—A publishing format for reproducible computational workflows.” In Proc., 20th Int. Conf. on Electronic Publishing, ELPUB 2016: Positioning and Power in Academic Publishing: Players, Agents and Agendas, 87–90. Amsterdam, Netherlands: IOS Press BV.
Niskanen, S. 2009. “Development of an open source model rocket simulation software.” Ph.D. thesis, Dept. of Applied Physics, Helsinki Univ. of Technology.
Notre Dame Rocketry Team. 2020. Flight readiness review—NASA student launch 2020—Lunar sample retrieval system and air braking system. Notre Dame, IN: Univ. of Notre Dame.
Panicucci, P., C. Allard, and H. Schaub. 2018. “Spacecraft dynamics employing a general multi-tank and multi-thruster mass depletion formulation.” J. Astronaut. Sci. 65 (4): 423–447. https://doi.org/10.1007/s40295-018-0133-0.
Petzold, L. 1983. “Automatic selection of methods for solving stiff and nonstiff systems of ordinary differential equations.” SIAM J. Sci. Stat. Comput. 4 (1): 136–148. https://doi.org/10.1137/0904010.
Rogers, C. E., and D. Cooper. 2019. Rogers Aeroscience RASAero II aerodynamic analysis and flight simulation program—User manual. Lancaster, CA: Rogers Aeroscience.
Thomson, W. T. 1966. “Equations of motion for the variable mass system.” AIAA J. 4 (4): 766–768. https://doi.org/10.2514/3.3544.
Thomson, W. T., and G. S. Reiter. 1965. “Jet damping of a solid rocket—Theory and flight results.” AIAA J. 3 (3): 413–417. https://doi.org/10.2514/3.2880.
Van Rossum, G., and F. L. Drake. 2009. Python 3 reference manual. Scotts Valley, CA: CreateSpace.
Virtanen, P., et al. 2020. “SciPy 1.0: Fundamental algorithms for scientific computing in Python.” Nat. Methods 17 (3): 261–272. https://doi.org/10.1038/s41592-019-0686-2.
Wilde, P. D. 2018. “Range safety requirements and methods for sounding rocket launches.” J. Space Saf. Eng. 5 (1): 14–21. https://doi.org/10.1016/j.jsse.2018.01.002.
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Published In
Journal of Aerospace Engineering
Volume 34 • Issue 6 • November 2021
Copyright
© 2021 American Society of Civil Engineers.
History
Received: Dec 21, 2020
Accepted: May 18, 2021
Published online: Aug 20, 2021
Published in print: Nov 1, 2021
Discussion open until: Jan 20, 2022
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