The T-220 is the largest Hall effect thruster in the P&W family. The first version of this engine was tested at NASA Glenn Research Center (GRC). The T-220HT is the high-power, high-thrust version. The T-220HT is an ideal size for orbit insertion and orbit transfer of large satellite systems. The T-220 or T-220HT can also be configured to operate in a dual mode: low specific impulse-high thrust for orbit insertion/transfer and high specific impulse-low thrust for station keeping.

The T-220 thrusters operate at 7 to 20 kW and produce 0.5 to 1.0 N of thrust with specific impulse values varying between 1,500 and 2,500 seconds, depending on operational conditions. The T-220 has undergone successful demonstration testing at NASA GRC for 1,000 hours and demonstrated about 2,500 seconds of specific impulse with very low material erosion.

The T-220HT has undergone extensive performance mapping under orbit transfer conditions at NASA GRC. The profile of the exhaust plume and radiated electromagnetic noise have also been measured. The results show that the T-220HT has a very narrow exhaust plume and it is electromagnetically very quiet.