EXPOSE-E: An ESA Astrobiology Mission 1.5 Years in Space

Abstract

The multi-user facility EXPOSE-E was designed by the European Space Agency to enable astrobiology research in space (low-Earth orbit). On 7 February 2008, EXPOSE-E was carried to the International Space Station (ISS) on the European Technology Exposure Facility (EuTEF) platform in the cargo bay of Space Shuttle STS-122 Atlantis. The facility was installed at the starboard cone of the Columbus module by extravehicular activity, where it remained in space for 1.5 years. EXPOSE-E was returned to Earth with STS-128 Discovery on 12 September 2009 for subsequent sample analysis. EXPOSE-E provided accommodation in three exposure trays for a variety of astrobiological test samples that were exposed to selected space conditions: either to space vacuum, solar electromagnetic radiation at >110 nm and cosmic radiation (trays 1 and 3) or to simulated martian surface conditions (tray 2). Data on UV radiation, cosmic radiation, and temperature were measured every 10 s and downlinked by telemetry. A parallel mission ground reference (MGR) experiment was performed on ground with a parallel set of hardware and samples under simulated space conditions. EXPOSE-E performed a successful 1.5-year mission in space.

Resistance of Bacterial Endospores to Outer Space for Planetary Protection Purposes—Experiment PROTECT of the EXPOSE-E Mission

“…Because the martian solar constant is only 45% that of Earth's (due to the difference in their distance from the Sun), the calculated Earth solar constant hours (s.c.h.) of PROTECT (Table 1 and Rabbow et al, 2012) correspond to about twice as much martian s.c.h. For example, the simulated martian UV fluence of 432 MJ/m 2 in tray 2, compartment 3 (Table 1) would need, at Mars' distance from the Sun, an irradiation for 3144 h instead of 1429 h in Earth's orbit.…”

Tanpopo: Astrobiology Exposure and Micrometeoroid Capture Experiments— Proposed Experiments at the Exposure Facility of ISS-JEM

“…These space exposure experiments have been reviewed in Horneck et al 25) . EXPOSE-E, EXPOSE-R, BIORISK and BIOMEX have been performed on ISS [26][27][28][29] . In Tanpopo mission, microbes with different depth of layered cells will be exposed to the space environment.…”

Cyanobacteria from Extreme Deserts to Space

“…Five short-duration missions (two weeks) were performed using the Russian Foton spacecraft carrying the European Space Agency (ESA) BIOPAN facility [3]. More recently another ESA facility, called EXPOSE, has provided a long-duration exposure platform (1.5 years) on the International Space Station (ISS), which provides a complete laboratory orbiting Earth at about 400 km [4,5]. New generation astrobiological experiments are being carried out by using nanosatellites, named cubesats [6] that orbit where the radiation dose is significantly higher (at least one order of magnitude) than on the ISS [7].…”

“…In this context, desiccation-, radiation-resistant desert strains of Chroococcidiopsis have been employed in several experimentations in LEO and ground-based simulations of space and Martian conditions in order to investigate the tenancy of life as we know it, to detect biosignatures to search for life on Mars and test the (litho)-Panspermia theory [4,5]. Since cyanobacteria started to introduce oxygen into the Earth atmosphere 2.5 billion years ago, the spectroscopic detection of oxygen in a planet's atmosphere has been suggested as an indicator of the presence of life, exploiting its star as its primary energy source [12].…”

“…Ground-based simulations carried out in preparation of the EXPOSE-E space mission [5] have shown that dried Chroococcidiopsis tolerate some space constraints; when shielded under 3 mm of sandstone they survived to simulated Mars-like UV radiation, UV radiation (200 -400 nm) and space vacuum as expected for 1.5 years permanence in LEO [33]. Recent ground-based simulations performed for the EXPOSE-R2 space mission, set to be launched in April 2014, documented that dried biofilms of Chroococcidiopsis exhibited an enhanced survival compared to planktonic dried cells under space and Martian simulations [39,40].…”