We need an overground facility, which is mainly supplies arrival, helipad/airport/port, guests and new recruits quarters (two separate things). And communication array and whatnot. Radar, that kind of things.
Underground we'll have barracks for security guards / all the security at level -1, the scientist quarters at -2, then the factories (making stuff for experiments) at -3, and starting at -4 the !!SCIENCE!! (the more dangerous the deeper, of course.)
Goal is to develop advanced weaponry based on recent scientific developments.
@Scelly9: feel free to dismiss what comes next if it doesnt fit your vision:
Year is 2021, the economic crisis is over, and the recovering nations are eyeing space. Private corporations are experimenting with asteroid mining, with little success and no economic viability so far. Tensions arise due to the lack of ressources, but global warming is somewhat averted. This station is not to look toward space, but have to prepare the next generation of weaponry for an eventual war (Which is highly unlikely, but as the saying goes, Ci Vis Pacem, Para Bellum. Who wants peace, prepares war.). Scientists and military analysts have free reins to determine what they will develop.
Human life is NOT expendable. Otherwise disregard ethics. Animal experiment is fine, GMing is fine, cloning animals is fine, not humans (not without debate).