space analogues

Analogue means in some ways comparable. But comparable to what? Human Spaceflight is nowadays confined to Low Earth Orbit, and it will be, for a few more years, to the Solar System. But there is no comparison between LEO, an Asteroid and Mars or the Moon, or even Libration Points in terms of atmosphere, gravity, soil composition, distance from Earth, mission duration, and therefore habitats, communication, equipment, operations.

So, first answer the question: Analogue to WHAT?

And then, it so highly depends on what one wants from the analogue: planetary science? Therefore (geo)logical analogy is required. Or maybe testing of equipment? Therefore environmental analogy is important. You want to test an operational concept? Then you also need some level of situational analogy. Human research? Depending on what you study, you need some combination of environmental, situational, operational analogy. And the level of realism needs to be a known assumption, to be seriously considered in the interpretation of results. Training? You need a REALISTIC combination of environmental, situational, operational analogy. And that's not easy to achieve, especially considering how little experience we have of the target.