Iodine Electric Propulsion System Tested in Space
An iodine electric propulsion system has been successfully tested in space for the first time. French thruster company ThrustMe recently successfully tested an iodine-fueled electric propulsion system in space, and the results have been published in the scientific journals, Nature.
“ThrustMe is pioneering the use of iodine within the space industry.”
Dmytro Rafalskyi, CTO and co-founder of ThrustMe.
The test results confirm for the first time that iodine is not only a viable alternative to conventional xenon propellant, but that it also enables extreme propulsion system miniaturization. This provides small satellites with new maneuvering and space exploration potential, and critical new collision avoidance and deorbiting capabilities that will prove vital for the long-term sustainability of the space industry.
Xenon is rare … less than 1 part per 10 million in the atmosphere … expensive (around $3000/kg), and commercial production is limited. Xenon is also used in competing applications in other sectors such as the medical, lighting, and semiconductor industries. Market projections estimate that more than 24,000 satellites could be launched within the next 10 years and most of them will require electric propulsion. Increasing space industry demand alone is expected to outpace supply in the coming years, and it is therefore critical that a viable replacement propellant be found. Iodine has been investigated as a possible game-changing alternative propellant within the space community by a number of universities, companies, and space agencies over the last 20 years, but no iodine propulsion system has previously been launched or tested in space.
“ThrustMe is pioneering the use of iodine within the space industry,” said Dmytro Rafalskyi, CTO and co-founder of ThrustMe. “Iodine is significantly more abundant and cheaper than xenon, and has the added advantage that it can be stored unpressurized as a solid."
Xenon must be stored under high-pressure (typically 100-200x atmospheric pressure). Iodine also has a storage density almost 3x higher than xenon, and 9x higher than krypton. This enables significant simplification and miniaturization of propulsion systems.
“ThrustMe has developed a revolutionary propulsion system with an iodine ion thruster, the NPT30-I2, which includes all needed subsystems and fits within a single package of roughly 10 cm x 10 cm x 10 cm,” said Dmytro. Comparison with xenon shows that iodine gives an almost 50% performance enhancement.
After extensive testing and qualification, the first NPT30-I2 iodine electric propulsion system was integrated into the Beihangkongshi-1 satellite operated by Spacety and launched into space by a Long March 6 rocket on November 6, 2020. Since then ThrustMe has been carefully analyzing propulsion system and satellite data and comparing in-flight results with ground-based measurements. Results confirm successful operation with expected performance, and definite satellite orbital changes matching predictions based on propulsion system telemetry.
The results of the in-orbit iodine electric propulsion system demonstration have been rigorously peer-reviewed and published in the scientific journal Nature. “Publication of these historic results is not only important for ThrustMe, but also for the space industry in general,” says Ane Aanesland, CEO and co-founder of ThrustMe. “Many new companies have entered the market in recent years but demonstrated evidence of flight heritage and performance transparency are missing. Having our results peer-reviewed and publically accessible provides the community with further confidence and helps to create a benchmark within the industry."
(Source: ThrustMe news release. Image provided)