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| Representational Image [credits - earthweb.ess.washington.edu] |
Iodine propellant for in-orbit propulsion system will open up a complete new area for the space industry
Spacecraft including satellites use propulsion systems to move around in space, helping them to change orbit or -- for an instance -- avoid collisions with other spacecrafts/space bodies. A key part of propulsion systems is the propellant – a substance expelled from the spacecraft to drive it forwards.
Current designs of spacecrafts use Xenon gas as propellent. Xenon is globally in short supply and expensive i.e. about US$3,000/kg in 2021. Some older designs used mercury as a propellant. However, mercury is toxic, tended to contaminate spacecraft, and was difficult to feed accurately. Notably, Krypton is used to fuel the Hall effect thrusters aboard Elon Musk's Starlink internet satellites, in part due to its lower cost than conventional xenon propellant.
Now in a latest, world’s first use of an iodine electric propulsion system in space was successfully demonstrated by ThrustMe, a France-based deep tech company that designs miniature aerospace thrusters for small satellites.
The iodine-powered propulsion system has been successfully operated in space onboard a small satellite with manoeuvres confirmed using satellite tracking data.
The results of this successful demonstration has been published in scientific journal - Nature. These 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.
Dmytro Rafalskyi, CTO of ThrustMe, and his colleagues now anticipate that demonstration's results will accelerate the adoption of alternative propellants within the space industry and demonstrate the potential of iodine for a wide range of space missions.
ThrustMe has developed NPT30-I2, a revolutionary propulsion system with an iodine ion thruster. NPT30-I2 includes all needed subsystems and fits within a single package of roughly 10 cm x 10 cm x 10 cm, that can be fitted into CubeSat - a type of miniaturized satellite.
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| ThrustMe’s NPT30-I2 fully integrated propulsion system that uses Iodine propellent [Image Credits - www.thrustme.fr] |
Iodine performed better than Xenon, the traditional fuel used for electric propulsion systems for space travel. Iodine does not poses any explosion risk as it is stored as a solid, unlike xenon which is stored under pressure. Moreover, Iodine cost 10 to 100 times less than xenon -- just to buy the same amount. These traits highlights iodine’s potential utility for future space missions.
Iodine is not only more abundant and cheaper than xenon but has the added advantage that it can be stored unpressurized as a solid. Whereas, Xenon by comparison 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, an another propellent and alternative of xenon.
According to ThrustMe --Iodine propellant for in-orbit propulsion system will open up a complete new area for the space industry; tiny satellites (the CubeSats) will finally be able to do propulsive operations and bigger satellites will gain considerably by reducing the complexity and cost of the propulsion system.