ion drive used on Tiangong has burned continuously for 8,240 hours without a glitch, indicating their suitability for the Chinese space station's designated 15-year lifespan. This is the world's first Hall thruster on a human-rated mission. The Jet Propulsion Laboratory (JPL) granted exclusive commercial licensing to Apollo Fusion, led by Mike Cassidy, for its Magnetically Shielded Miniature (MaSMi) Hall thruster technology. In January 2021, Apollo Fusion announced they had secured a contract with York Space Systems for an order of its latest iteration named the "Apollo Constellation Engine". The NASA mission to the asteroid Psyche will utilize xenon gas Hall thrusters. The electricity will come from the craft's 75 square meter solar panels. NASA's first Hall thrusters on a human-rated mission will be a combination of 6 kW Hall thrusters provided by Busek and NASA Advanced Electric Propulsion System (AEPS) Hall thrusters. They will serve as the primary propulsion on Maxar's Power and Propulsion Element (PPE) for the Lunar Gateway under NASA's Artemis program. The high specific impulse of Hall thrusters will allow for efficient orbit raising and station keep for the Lunar Gateway's polar near-rectilinear halo orbit. In development The highest power Hall-effect thruster in development (as of 2021) is the University of Michigan's 100 kW X3 Nested Channel Hall Thruster. The thruster is approximately 80 cm in diameter and weighs 230 kg, and has demonstrated a thrust of 5.4 N. Other high power thrusters include NASA's 40 kW Advanced Electric Propulsion System (AEPS), meant to propel large-scale science missions and cargo transportation in deep space. References External links Edgar, Y. (2009). New Dawn for Electric Rockets SITAEL S.p.A. (Italy)—Page presenting Hall effect thruster products & data sheets Snecma SA (France) page on PPS-1350 Hall thruster Electric Propulsion Sub-Systems (PDF) Stationary plasma thrusters (PDF) ESA page on Hall thrusters Apollo Fusion Thruster Magnetic propulsion devices Ion engines Soviet inventions