The OREOcube project investigates the effects of solar and cosmic radiation on organic molecules of relevance to astrochemistry and astrobiology. OREOcube is designed to perform in-situ UV-Vis-NIR spectroscopy to study the photochemistry of organic thin films in contact with inorganic substrates while exposed to the space environment outside the International Space Station (ISS). The experiment is part of the European Space Agency's ExoBio facility and builds on the heritage of the O/OREOS (Organism/Organic Exposure to Orbital Stresses) nanosatellite and its SEVO (Space Environment Viability of Organics) payload.

In contrast to previous passive exposure platforms on the ISS, OREOcube will monitor photochemical changes through time-resolved in-situ UV-Vis-NIR spectroscopy during space exposure. Spectra of selected organic compounds will be recorded at regular intervals to follow their photochemical evolution throughout the mission. Launch to the ISS is currently planned for 2027, followed by approximately six months of space exposure. A particular focus is placed on organic compounds relevant to the emergence and detection of life on Earth and other planets, such as Mars.

By depositing organic samples as UV-transparent thin films onto inorganic substrates, structural changes and organic–inorganic interactions can be examined to understand the role that solid mineral surfaces play in the photochemical alteration of organic molecules in interstellar and planetary environments. Candidate organic molecules include polycyclic aromatic hydrocarbons, quinones and porphyrins, while inorganic substrates of interest include silicates, metal oxides, iron sulfides and iron–nickel alloys. By measuring changes in the UV-Vis-NIR spectra over time, OREOcube will provide kinetic and mechanistic information that cannot be obtained from passive exposure experiments. Combining these in-situ measurements with post-flight sample analyses will allow detailed investigations of radiation-induced chemical transformations under real space conditions.