MEED exposure facility mounted on the camera beam of the lunar orbiter of the Apollo 16 mission (A) and sample cuvette for exposing dry layers of microorganisms to solar UV radiation and space vacuum (B). MEED exposure facility mounted on the camera beam of the lunar orbiter of the Apollo 16 mission (A) and sample cuvette for exposing dry layers of microorganisms to solar UV radiation and space vacuum (B). (Reprinted from reference 245.) Gerda Horneck et al. Microbiol. Mol. Biol. Rev. 2010; doi:10.1128/MMBR.00016-09