“A new electric thruster that blasts out iodine has now been successfully tested in orbit, a milestone that could help lead to significantly tinier, simpler, cheaper and higher-performance engines for satellites and spacecraft, a new study reports.
Conventional rockets use chemical reactions to drive propulsion. In contrast, electric thrusters produce thrust by using electric power to accelerate propellants such as electrically charged ions away from a spacecraft.
Electric propulsion generates much less thrust than chemical rockets, making it too weak to launch a spacecraft from Earth’s surface. But electric thrusters are highly efficient at producing thrust, given the small amount of propellant they carry. This makes them very useful for spacecraft that are already in space.”
https://www.space.com/spacecraft-propulsion-iodine-ion-engine-tested-orbit
Both the Russian and Chinese space programs are pushing ion drive as their main propulsion technology for space travel. The Chinese space station already uses ion drives for station keeping and the massive Russian space tug will use nuclear power to generate electricity for its ion drives.
The Chinese have had one of their ion drive engines running for 11 months straight and has begun ground testing of a 50 KW ion drive designed for crewed and cargo missions to the Moon and Mars. They’re also working on a 20 KW ion drive for a mission to Jupiter to be launched as early as 2028.