The O/OREOS Mission: First Science Data from the Space Environment Viability of Organics (SEVO) Payload

Abstract

We report the first science results from the Space Environment Viability of Organics (SEVO) payload aboard the Organism/Organic Exposure to Orbital Stresses (O/OREOS) free-flying nanosatellite, which completed its nominal spaceflight mission in May 2011 but continues to acquire data biweekly. The SEVO payload integrates a compact UV-visible-NIR spectrometer, utilizing the Sun as its light source, with a 24-cell sample carousel that houses four classes of vacuum-deposited organic thin films: polycyclic aromatic hydrocarbon (PAH), amino acid, metalloporphyrin, and quinone. The organic films are enclosed in hermetically sealed sample cells that contain one of four astrobiologically relevant microenvironments. Results are reported in this paper for the first 309 days of the mission, during which the samples were exposed for ∼2210 h to direct solar illumination (∼1080 kJ/cm(2) of solar energy over the 124-2600 nm range). Transmission spectra (200-1000 nm) were recorded for each film, at first daily and subsequently every 15 days, along with a solar spectrum and the dark response of the detector array. Results presented here include eight preflight and 16 in-flight spectra of eight SEVO sample cells. Spectra from the PAH thin film in a water-vapor-containing microenvironment indicate measurable change due to solar irradiation in orbit, while three other nominally water-free microenvironments show no appreciable change. The quinone anthrarufin showed high photostability and no significant spectroscopically measurable change in any of the four microenvironments during the same period. The SEVO experiment provides the first in situ real-time analysis of the photostability of organic compounds and biomarkers in orbit.

Photochemistry of Polycyclic Aromatic Hydrocarbons in Cosmic Water Ice: The Role of Pah Ionization and Concentration

“…Radich et al (2014) have shown that, in aqueous media, UV-generated OH radicals trigger graphene (very large PAHs) scission into smaller, PAH-like compounds that, with continued irradiation, produce CO 2 and H 2 O. Likewise, Mattioda et al (2012), who studied PAH photochemistry in different environmental cells, show that the loss of the PAH isoviolanthrene (C 34 H 18 ) with growth of CO 2 occurs only water vapor is present in the chamber.…”

The AMINO experiment: exposure of amino acids in the EXPOSE-R experiment on the International Space Station and in laboratory

“…The experiment SEVO used a triple-cube satellite Mattioda et al 2012), whereas the experiment Perseus took place on the Mir station and the experiments PROCESS, AMINO and ORGANIC on Expose-E or Expose-R onboard the ISS (Boillot et al 2002;Bertrand et al 2012;Cottin et al 2012;Noblet et al 2012). Different organic compounds were thus exposed, including amino acids and their derivatives, peptides, nucleic bases, polymers (polyoxymethyl, polyacrylonitrile, polycyclic aromatic hydrocarbons PAH, tholins, etc.…”

A Critical Review of PAHs as DIB Carriers - Progress and Open Questions

“…As a direct result of these advances and the concomitant advances achieved through complementary studies involving astronomical observations of DIBs, laboratory simulation of interstellar analogs for neutral and ionized PAHs (Salama 2008 and references therein; Salama et al 2011;Gredel et al 2011), space exposure experiments of PAHs (Ehrenfreund et al 2007;Bryson et al 2011;Mattioda et al 2012), theoretical calculations of PAH spectra (Weisman et al 2003;Ruiterkamp et al 2005) and the modeling of diffuse and translucent interstellar clouds (Snow and McCall 2006 and references therein) it has become possible to further test the validity of the 'PAH-DIB' proposal.…”