This interesting article mentions one of the soil stars, the Tardigrade, which has survived space travel. In fact, 68% Tardigrade came back to Earth alive after being launched into space without spacesuits!
Here is the excerpt about them from the article on alien microbes:
“Little, if anything, is (publicly) known yet about the actual characteristics of the “alien” bacteria. The fact that they were found on the outside of the ISS, in low-Earth orbit, is intriguing, but nothing conclusive can be said until it can be determined they didn’t originate from Earth itself. There are many different kinds of microorganisms on Earth, and it is possible that some could get lofted into low-Earth orbit. They are already known to exist in the upper atmosphere and it’s also known that at least one type of microorganism can survive in space itself for some periods of time – tardigrades (water bears). In 2007, some living tardigrades were sent into space on the outside of a FOTON-M3 rocket for ten days by European researchers. 68 percent of them survived the trip, including coming back to Earth. Perhaps there are some other tiny earthly bugs which could do that as well.”
Read the full article from EarthSky here.