ELECTROJET THRUSTER TO BALANCE AN AERODYNAMIC DRAG ON A SMALL SPACECRAFT IN A VERY LOW EARTH ORBIT

Abstract

The goal of this paper is to study the feasibility of an electrojet thruster for a long-term operation in a very low Earth orbit. The paper presents the advantages of very low orbits and substantiates the importance of their exploitation. The main obstacle to their use is a gas-dynamic drag on a spacecraft in the Earth‘s upper atmosphere. At present, the dominant concept of its balancing is to employ an electrojet thruster that uses the surrounding gas to produce a balancing thrust. In developing a thrust system of this type, the principal task is to design a device for collecting a sufficient gas amount from the surrounding atmosphere.  However, in the course of development it turned out that the properties of the upper atmosphere components do not allow one to produce a thrust sufficient for atmospheric drag balancing. The existing gas collection systems proved to be incapable of providing the required gas accumulation rate. The paper proposes an alternative concept of an electrojet thruster for atmospheric drag balancing, which is based on the author’s experience in the development of plasma devices for the deposition of functional metal coatings. The paper analyzes the possibility of replacing a propellant gas for an electrojet thruster with a condensed working medium: a metal. For this purpose, the concept of a hybrid electrojet thuster is developed. The concept is based on combining a vacuum arc discharge and a magnetron discharge in a single plasma device. A pulsed vacuum arc discharge serves as an electron source to initiate and maintain a gasless magnetron self-sputtering discharge. In this case, the arc device can produce a microthrust. The main thrust is produced in the magnetron device by metal sputtering, ionization, and ion acceleration. In the joint operation of both discharges, the magnetron discharge implements a gasless magnetron self-sputtering mode, which is similar to the BP HiPIMS bipolar high-current pulsed magnetron sputtering mode. A conceptual plasma device model is developed to verify the feasibility of a hybrid electrojet thruster. The preliminary results confirm the operability of the plasma device arrangement and the feasibility of a gasless thrust system as an alternative to the existing concept.

REFERENCES

1. Crisp N. H., Roberts P. E., Livadiotti S. The benefits of very low earth orbit for earth observation missions. Progress in Aerospace. 2020. V. 117. Art. 100169. https://doi.org/10.1016/j.paerosci.2020.100619

2. State-of-the-Art Small Spacecraft Technology, NASA/TP−20260003140. URL: https://www.nasa.gov 2026/05soa-2026. (Last accessed on February 18, 2026).

3. Peng Zheng, Jianjun Wu, Yu Zhang. A comprehensive review of atmosphere breathing electric propulsion. International Journal of Aerospace Engineering. 2020. Art. 8811847. 21 pages.
https://doi.org/10.1155/2020/8811847

4. Hsu Andrea, Dragnea Horatiu, Schilling John 2223. Small Satellite Propulsion Technologies. Compendium The Aerospace Corporation, DISTRO A, Version 1.41. DISTRO A: Approved for public release. OTR-2024-00338. URL: https://aerospace.org/sites/default/files/2024-02/20231218%20Small%20Satellite%20Propulsion%20Survey_DISTRO_A.pdf (Last accessed on February 18, 2026).

5. Goebel D. M., Katz I., Mikellides I. G. Fundamentals of Electric Propulsion: Ion and Hall Thrusters. Jet Propulsion Lab. California Institute of Technology. March 2008. 486 pp. URL: https://descanso.jpl.nasa.gov/SciTechBook/series1/Goebel__cmprsd_opt.pdf (Last accessed on February 18, 2026).https://doi.org/10.1002/9780470436448

6. Navarro-Cavalle J., Wijnen M., Fajardo P. Ahedo E.. Development and characterization of the helicon plasma thruster prototype HPT05M. 36th International Electric Propulsion Conference. Vienna. Austria. September 15-20, 2019. URL: https://ep2.uc3m.es/assets/docs/pubs/conference_proceedings/nava19.pdf (Last accessed on February 18, 2026).

7. Giannetti V., Ferrato E., Andreussi T. On the critical parameters for feasibility and advantage of air-breathing electric propulsion systems. Acta Astronautica. 2024. V. 220. P. 345-355. https://doi.org/10.1016/j.actaastro.2024.04.042

8. Reinhard P., Neumann C. Centre-Triggered Pulsed Cathodic Arc Spacecraft Propulsion. URL:http://hdl.handle.net/2123/13810 (Last accessed on February 18, 2026).

9. Aksenov I. I. et al. Vacuum Arc: Plasma Sources, Coating Deposition, and Surface Modification. Kyiv: Naukova Dumka, 2012. 727 pp. (In Russian).

10. Mesyats G. A. Ecton or electron avalanche from metal. Physics-Uspekhi. 1995. V. 38. No. 6. Pp. 567- 590.https://doi.org/10.3367/UFNr.0165.199506a.0601

11. Duppada Guru Sankar, Taploo Anmol, Soni Vikas, Karp Adam, Spinelli Jake, Keidar Michael. Side feeding mechanism for micro cathode arc thruster. Journal of Electric Propulsion. 2025. V. 4. Art. 16 (2025).
https://doi.org/10.2514/6.2025-2385

12. Merino M. Ahedo E. Magnetic nozzles for space plasma thrusters. Encyclopedia of Plasma Technology. 2016. URL: https://www.taylorfrancis.com/books/e/9781351204958/chapters/10.10 (Last accessed on February 18, 2026).

13. Kuzmichev A. I. Magnetron Sputtering Systems. Kyiv: Avers, 2008, 244 pp. (In Russian).

14. Anders André High Power Impulse Magnetron Sputtering: A journey from early research, Encyclopedia of Plasma Technology - Two Volume Set, eBook ISBN9781351204958 Guðmundsson J. T. аt al AVS Seminar - Plasma Applications Group Santa Clara, CA. 2011. May 12. URL: https://nccavs-usergroups.avs.org/wp-content/uploads/PAG2011/2011_5anders.pdf (Last accessed on February 18, 2026).

15. Anders Andre, Andersson J. Gasless sputtering: Opportunities for ultraclean metallization, coatings in space, and propulsion. Appl. Phys. Lett. 2008. V. 92. Art. 221503.
https://doi.org/10.1063/1.2938414

16. Gryshkevych A. D., Khitko A. V. Using a plasma electron source in a magnetron ion sputtering system. Problems in High-Temperature Engineering. 2011. Pp. 42-45. (In Russian).

17. Tiron V., Velicu I-L. Understanding the ion acceleration mechanism in bipolar HiPIMS: the role of the double Layer structure developed in the after-glow plasma. Plasma Sources Science and Technology. 2020. V. 29. No. 1. Art. 015003. https://doi.org/10.1088/1361-6595/ab6156

18. Avino F. at al. After-glow dynamics of plasma potential in bipolar HiPIMS discharges. Plasma Sources Sci. Technol. 2021. V. 30. Art. 115015. https://doi.org/10.1088/1361-6595/ac2aed

19. Yang Luo, Mingyue Han, Duoduo Li, Ling Tang et al. Plasma potential and ion energy characteristics in BP-HiPIMS discharge with double layer. Plasma Sources Science and Technology. 2024. V. 33. Art. 105007. https://doi.org/10.1088/1361-6595/ad52bf

20. Gryshkevych O. D., Hryniuk S. I. Magnetron formation and use of intensive gas-metal plasma flows. Teh. Meh. 2019. No. 2. Pp. 102-113. (In Russian). https://doi.org/10.15407/itm2019.02.102

21. Gryshkevych O. D., Hryniuk S. I. Development and study of a prototype low-frequency power source for a high-current pulsed magnetron discharge. Teh. Meh. 2019. No. 4. Pp. 137-147. (In Russian).
https://doi.org/10.15407/itm2019.04.137

22. . Raizer Yu. P. Fundamentals of the Modern Physics of Gas-Discharge Processes. Moscow: Nauka, 1980. 415 pp. (In Russian).