If I’m doing my math right, the 25kg AEPS engine would need to produce 245N to even hover without any payload. So it’s theoretical max is about 0.9% of what’s needed to even lift itself.
And of course these figures get much worse when you consider the other components that are a necessary part of the engine working, namely, the xenon fuel tank and massive solar panel array.
For a relevant comparison, the thrust-to-weight ratio of the Merlin 1D engine by itself is something like 180:1, but the overall thrust-to-weight ratio of the entire rocket at launch is only 1.4:1. So just in order to get a rocket that can lift off at all and deliver useful payload to orbit you need at least a 3-digit thrust-to-weight ratio on the engine itself. Ion thrusters don't remotely come close.
