Two things I noticed:
Most of them were single-cell organisms, based on biochemistry completely alien to those found on Earth.
The way the sentence is structured, IMO "those" should be "that"....'cause "biochemistry."
Martini finished setting up the laser drill and activated it. It began melting the ice, the water sublimating into a gas that escaped into the vacuum.
The thing about sublimation is that it is a direct transition of a solid to the gaseous state. The ice does not melt, there is no water, there is only ice and then water vapor.
PS: “Evaporate” would work instead of “sublimate.” But I think that was not what you were intending to state(ha!).
You are absolutely correct!