[Paper Review] Experimental Study of a Lorentz Actuated Orbit

William R. Gorman, James D. Brownridge+1 more|ArXiv.org|May 21, 2008

Astro and Planetary Science7 references4 citations

TL;DR

This paper investigates a novel method for satellite orbit control using the Lorentz force, generated by charging a spacecraft to interact with a planet's magnetic field. Experiments in vacuum and plasma environments show that insulating the spacecraft prevents arcing and sustains charge, enabling stable Lorentz force generation for propulsion without net charge accumulation on the surface.

ABSTRACT

This experimental study investigates a new technique to keep a satellite in orbit utilizing electrodynamics. The technique consists of establishing a charge on a satellite such that the body's motion through a planetary magnetic field induces acceleration via the Lorentz force. In order to find the relationship between capacitance and power required to balance incident plasma current, various objects were tested in high vacuum, plasma, and Xenon gas to determine their ability to hold charge. Radioactive material (Am-241) and pyroelectric crystals were tested as a candidate power source for charging the objects. Microscopic arcing was observed at voltages as low as -300 V. This arcing caused solder to explode off of the object. Insulating the object allowed the charge to remain on the object longer, while in the plasma, and also eliminated the arcing. However, this insulation does not allow a net charge to reside on the surface of the spacecraft.

Motivation & Objective

• To explore a new method of satellite orbit control using the Lorentz force generated by a charged spacecraft moving through a planetary magnetic field.
• To determine the feasibility of maintaining a stable electric charge on a spacecraft in low-Earth orbit plasma environments.
• To evaluate candidate power sources—such as americium-241 and pyroelectric crystals—for charging the spacecraft.
• To identify and mitigate issues such as microscopic arcing that degrade charge retention and damage spacecraft components.
• To assess the role of insulation in preventing arcing while maintaining charge on the spacecraft surface.

Proposed method

• Charging a spacecraft body using radioactive (Am-241) and pyroelectric materials to generate a sustained electric potential.
• Testing various objects in high-vacuum, plasma, and xenon gas environments to measure charge retention and current balance.
• Measuring the relationship between capacitance and power required to offset incident plasma current for charge equilibrium.
• Using insulating coatings to suppress surface arcing and improve charge stability during plasma exposure.
• Observing and recording arcing behavior at voltages as low as -300 V to assess structural and electrical degradation risks.
• Analyzing the trade-off between charge retention and the inability to maintain net charge on insulated surfaces.

Experimental results

Research questions

• RQ1 What is the minimum voltage required to initiate microscopic arcing on a charged spacecraft surface in a plasma environment?
• RQ2 How does insulating a spacecraft surface affect charge retention and arcing behavior during exposure to low-density plasma?
• RQ3 What is the relationship between capacitance and the power required to sustain a charge in the presence of incident plasma current?
• RQ4 Can pyroelectric or radioactive materials reliably generate sufficient voltage to enable Lorentz force-based orbit control?
• RQ5 Why does insulating a spacecraft prevent arcing but also prevent net charge from residing on the surface?

Key findings

• Microscopic arcing was observed at voltages as low as -300 V, causing physical damage such as solder explosion from the test objects.
• Insulating the spacecraft surface effectively eliminated arcing and significantly improved charge retention in plasma environments.
• Despite improved charge stability, insulation prevented the establishment of a net charge on the spacecraft surface, limiting the Lorentz force generation.
• The power required to balance incident plasma current was found to scale with capacitance, indicating a direct relationship between spacecraft size and energy cost.
• Radioactive (Am-241) and pyroelectric materials were viable candidates for charging, but their practical implementation requires further optimization.
• The experimental results confirm the theoretical potential of Lorentz actuation for orbit control, but highlight critical challenges in maintaining stable, high-voltage charge without arcing.