Abstract
The growing emphasis on spacecraft sustainability through in-space servicing, assembly, and manufacturing highlights the need for ongoing technological advancement in this complex and multi-disciplinary area. Small multi-agent spacecraft teams will likely play a key role in autonomous and routine in-space servicing and assembly missions. The team, as a whole, must operate with fuel efficiency while adhering to various constraints such as maintaining a minimum inter-agent separation distance to prevent collisions during the servicing or assembly operation. In this paper, we present a novel approach for multi-agent path-constrained trajectory optimization using indirect methods, without increasing the problem size. Using a hyperbolic tangent function and smoothing, we successfully formulate the constrained multi-agent trajectory planning problem as a single indirect optimal control problem, guaranteeing that the converged solution is at least locally optimal and that the path constraints are always satisfied while retaining the trajectories as single arcs. The hyperbolic tangent function is employed to smooth the transition from an inactive to an active path constraint, with the final solution exhibiting the true constrained motion. Multi-agent trajectory optimization simulations are performed using a unique relative dynamical model, based on circular restricted three-body problem dynamics, with a frame-center shift as well as a smaller distance unit to better condition the problem for numerical convergence. We demonstrate the performance of the algorithm by simulating different configurations of agents (i.e., 2, 3 and 4 agents) simultaneously transporting modular components between a service vehicle (100 m away) and a space telescope undergoing servicing or assembly, in a Halo orbit at Sun–Earth L2, while satisfying the specified inter-agent anti-collision constraint. An independent validation of the method is also provided by solving the well-known Brachistochrone problem while satisfying a prescribed linear path constraint.









Similar content being viewed by others
Explore related subjects
Discover the latest articles and news from researchers in related subjects, suggested using machine learning.Data Availability
Not applicable.
References
Mukherjee, R., Siegler, N., Thronson, H., Aaron, K., Arenberg, J., Backes, P., Barto, A., Belvin, K., Bowman, L., Calero, D., et al.: When is it worth assembling observatories in space? Bull. Am. Astron. Soc. 51(7), 50 (2019)
Saleh, J.H., Lamassoure, E.S., Hastings, D.E., Newman, D.J.: Flexibility and the value of on-orbit servicing: new customer-centric perspective. J. Spacecr. Rocket. 40(2), 279–291 (2003). https://doi.org/10.2514/2.3944
Belvin, W.K., Doggett, W.R., Watson, J.J., Dorsey, J.T., Warren, J.E., Jones, T.C., Komendera, E.E., Mann, T., Bowman, L.M.: In-space structural assembly: applications and technology. https://doi.org/10.2514/6.2016-2163
NASA: On-orbit servicing, assembly, and manufacturing 1 (OSAM-1) (2023). https://www.nasa.gov/mission/on-orbit-servicing-assembly-and-manufacturing-1/. Accessed 21 Feb 2024
Northrop Grumman: Space logistics services (2024). https://www.northropgrumman.com/space/space-logistics-services. Accessed 28 Feb 2024
Spry, J.: US Space Force wants to test how to build satellites in orbit with \$1.6 million Arkisys deal (2023). https://www.space.com/space-force-picks-arkisys-to-build-satellites-in-orbit. Accessed 21 Feb 2024
Betts, J.: Practical Methods for Optimal Control Using Nonlinear Programming. Society for Industrial and Applied Mathematics, Philadelphia (2001). https://doi.org/10.1137/1.9781611976199.ch1
Hargraves, C.R., Paris, S.W.: Direct trajectory optimization using nonlinear programming and collocation. J. Guid., Control, Dyn. 10(4), 338–342 (1987). https://doi.org/10.2514/3.20223
Bandyopadhyay, S., Baldini, F., Foust, R., Rahmani, A., Croix, J.-P., Chung, S.-J., Hadaegh, F.: Distributed spatiotemporal motion planning for spacecraft swarms in cluttered. Environments (2017). https://doi.org/10.2514/6.2017-5323
Morgan, D., Subramanian, G.P., Chung, S.-J., Hadaegh, F.Y.: Swarm assignment and trajectory optimization using variable-swarm, distributed auction assignment and sequential convex programming. Int. J. Robot. Res. 35(10), 1261–1285 (2016). https://doi.org/10.1177/0278364916632065
Morgan, D., Subramanian, G.P., Bandyopadhyay, S., Chung, S.-J., Hadaegh, F.Y.: Probabilistic guidance of distributed systems using sequential convex programming. In: 2014 IEEE/RSJ International Conference on Intelligent Robots and Systems, pp. 3850–3857 (2014). https://doi.org/10.1109/IROS.2014.6943103
Wang, L., Ames, A.D., Egerstedt, M.: Safety barrier certificates for collisions-free multirobot systems. IEEE Trans. Robot. 33(3), 661–674 (2017). https://doi.org/10.1109/TRO.2017.2659727
Bhatt, M., Jia, Y., Mehr, N.: Efficient constrained multi-agent trajectory optimization using dynamic potential games. In: 2023 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), pp. 7303–7310 (2023). https://doi.org/10.1109/IROS55552.2023.10342328
Pontryagin, L.S.: Mathematical Theory of Optimal Processes, 1st edn. Classics of Soviet Mathematics, vol. 4. Routledge, London (1987). https://doi.org/10.1201/9780203749319
Bryson, A.E., Ho, Y.-C.: Applied Optimal Control: Optimization, Estimation, And Control, 1st edn. Routledge, New York (1975). https://doi.org/10.1201/9781315137667
Pavlak, T.A.: Trajectory design and orbit maintenance strategies in multi-body dynamical regimes. Ph.D. Dissertation, Purdue University, West Lafayette, IN (2013). https://engineering.purdue.edu/people/kathleen.howell.1/Publications/Dissertations/2013_Pavlak.pdf
Patrick, B., Pascarella, A., Woollands, R.: Hybrid optimization of high-fidelity low-thrust transfers to the lunar gateway. J. Astronaut. Sci. 70(4), 27 (2023). https://doi.org/10.1007/s40295-023-00387-7
Sidhoum, Y., Oguri, K.: Indirect forward-backward shooting for low-thrust trajectory optimization in complex dynamics. J. Guid., Control, Dyn. 47(10), 2164–2172 (2024). https://doi.org/10.2514/1.G007997
Pascarella, A., Woollands, R., Pellegrini, E., Net, M.S., Xie, H., Hook, J.V.: Low-thrust trajectory optimization for the solar system pony express. Acta Astronaut. 203, 280–290 (2023). https://doi.org/10.1016/j.actaastro.2022.11.046
Graichen, K., Kugi, A., Petit, N., Chaplais, F.: Handling constraints in optimal control with saturation functions and system extension. Syst. Control Lett. 59(11), 671–679 (2010). https://doi.org/10.1016/j.sysconle.2010.08.003
Grant, M.J., Braun, R.D.: Rapid indirect trajectory optimization for conceptual design of hypersonic missions. J. Spacecr. Rocket. 52(1), 177–182 (2015). https://doi.org/10.2514/1.A32949
Antony, T., Grant, M.J.: Path constraint regularization in optimal control problems using saturation functions. In: 2018 AIAA Atmospheric Flight Mechanics Conference, p. 0018 (2018). https://doi.org/10.2514/6.2018-0018
Salemme, G., Armellin, R., Lizia, P.D.: Continuous-thrust collision avoidance manoeuvres optimization. In: AIAA Scitech 2020 Forum (2020). https://doi.org/10.2514/6.2020-0231
Hernando-Ayuso, J., Bombardelli, C.: Low-thrust collision avoidance in circular orbits. J. Guid. Control. Dyn. 44(5), 983–995 (2021). https://doi.org/10.2514/1.G005547
Curtis, H.D.: Orbital Mechanics for Engineering Students, Elsevier Aerospace Engineering Series, 4th edn. Butterworth-Heinemann, Oxford, Cambridge (2020)
Prussing, J.E., Conway, B.A.: Orbital Mechanics, 2nd edn. Oxford University Press, New York (2013)
Ardaens, J., D’Amico, S.: Control of formation flying spacecraft at a Lagrange point. Deutsches Zentrum Für Luft. No. 00-08 (2008)
Scorsoglio, A., Furfaro, R., Linares, R., Massari, M.: Relative motion guidance for near-rectilinear lunar orbits with path constraints via actor-critic reinforcement learning. Adv. Space Res. 71(1), 316–335 (2023). https://doi.org/10.1016/j.asr.2022.08.002
Lawden, D.F.: Optimal Trajectories for Space Navigation. Mathematical texts. Butterworth & Co., London, Butterworths (1963)
Taheri, E., Junkins, J.L.: Generic smoothing for optimal bang-off-bang spacecraft maneuvers. J. Guid. Control. Dyn. 41(11), 2470–2475 (2018). https://doi.org/10.2514/1.G003604
Woollands, R.M., Taheri, E., Junkins, J.L.: Efficient computation of optimal low thrust gravity perturbed orbit transfers. J. Astronaut. Sci. 67(2), 458–484 (2019). https://doi.org/10.1007/s40295-019-00152-9
MathWorks: Solve system of nonlinear equations—MATLAB fsolve (2024). https://www.mathworks.com/help/optim/ug/fsolve.html. Accessed 11 Feb 2024
Shafer, D.S.: The Brachistochrone: Historical Gateway to the Calculus of Variations. Mater. Mat. 0001-14 (2007)
Haws, L., Kiser, T.: Exploring the Brachistochrone problem. Am. Math. Mon. 102(4), 328–336 (1995). https://doi.org/10.1080/00029890.1995.11990579
Johnson, N.P.: The Brachistochrone problem. Coll. Math. J. 35(3), 192–197 (2004). https://doi.org/10.1080/07468342.2004.11922072
Antony, T.: Large scale constrained trajectory optimization using indirect methods. PhD Thesis, Purdue University (2018). https://docs.lib.purdue.edu/open_access_dissertations/1708/. Accessed 21 Aug 2024
Small spacecraft systems virtual institute: state-of-the-art small spacecraft technology. Technical Report NASA/TP-2024-10001462, NASA, Ames Research Center, Moffett Field, CA (2024). https://www.nasa.gov/smallsat-institute/sst-soa/. Accessed 02 Mar 2024
Martínez Martínez, J., Lafleur, T.: On the selection of propellants for cold/warm gas propulsion systems. Acta Astronaut. 212, 54–69 (2023). https://doi.org/10.1016/j.actaastro.2023.07.031
NASA James Webb Space Telescope: Webb Key Facts (2022). https://webb.nasa.gov/content/about/faqs/facts.html. Accessed 10 Sep 2022
Acknowledgements
This work was partially supported by Ten One Aerospace through a NASA STTR Phase I research grant: 80NSSC22PB217. The first author also acknowledges fellow graduate student, Bryan Cline, for his valuable insights and conversations with regard to formulation of the optimal control problem.
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
Conflict of interest
On behalf of all authors, the corresponding author states that there is no conflict of interest.
Additional information
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
About this article
Cite this article
Bommena, R., Woollands, R. Indirect Trajectory Optimization with Path Constraints for Multi-Agent Proximity Operations. J Astronaut Sci 71, 54 (2024). https://doi.org/10.1007/s40295-024-00470-7
Accepted:
Published:
DOI: https://doi.org/10.1007/s40295-024-00470-7


