There was that ISS experiment during multiple spacewalks that discovered marine microorganisms on the outer surface of the space station that got there somehow,

There was that ISS experiment during multiple spacewalks that discovered marine microorganisms on the outer surface of the space station that got there somehow, many of them surviving the conditions. It's hard to explain by the contamination alone because some species were endemic to the places well outside the trajectory of the launchers. The authors suggest/speculate about the existence of some ionospheric updraft or electromagnetic phenomenon capable of elevating them to the upper thermosphere where ISS is located. If that's true, panspermia hypothesis suddenly becomes much less far-fetched, and also the "reverse panspermia" you're talking about. https://www.hindawi.com/journals/tswj/2018/7360147/ https://www.hindawi.com/journals/tswj/2018/7360147/ - one of the papers related to the experiment https://nplus1.ru/material/2020/02/21/iss-test-experiment https://nplus1.ru/material/2020/02/21/iss-test-experiment - a pop-sci article and an interview with a PI of that experiment (in Russian, use a translator)