Mars Astrobiology: Recent Status and Progress - Planetary Exploration and Science: Recent Results and Advances - page 224

they will be able to grow and develop at that IR and visible light radiation levels
found on Mars. But this is not the only factor to influence growth; gravity also
strongly affects the photosynthetic organisms' growth and development; thus, it
is fundamentally necessary to study gravity effects on them, firstly, simulating a
Martian 0.38 g aboard the ISS for gaining data, results, and operational experience
and, later, on real Mars environment (de Morais 2004 ).
There are no data on growth effects on microbes and plants within gravitational
fields such as the 0.38 g of Mars. There is, however, a large body of research on
the effects of 0 g on them from experiments flown aboard rockets, the Apollo
program, satellites (such as the Cosmos series, the Long Duration Exposure Facility,
the BIOPAN facility, etc.), the Space Shuttle, the MIR space station, and the
International Space Station (ISS) (EXPOSE facility, etc.) (de Morais 2004 ).
Life Under Simulated Martian Conditions: Experiments
On 26 April 2012, scientists reported that an extremophile lichen survived and
showed remarkable results on the adaptation capacity of photosynthetic activity
within the simulation time of 34 days under Martian conditions in the Mars
Simulation Laboratory (MSL) maintained by the German Aerospace Center (DLR).
However, the ability to survive in an environment is not the same as the ability to
thrive, reproduce, and evolve in that same environment, necessitating further study.
EXPOSE
EXPOSE was a multiuser facility mounted outside the International Space Station
(ISS) dedicated to astrobiology. EXPOSE was developed by the European Space
Agency (ESA) for long-term space flights and was designed to allow exposure
of chemical and biological samples to outer space while recording data during
exposure.
The results will contribute to our understanding of photobiological processes in
simulated radiation climates of planets (e.g., early Earth, early and present Mars, and
the role of the ozone layer in protecting the biosphere from harmful UVB radiation),
as well as studies of the probabilities and limitations for life to be distributed beyond
its planet of origin.
EXPOSE data support long-term in situ studies of microbes in artificial mete-
orites, as well as of microbial communities from special ecological niches. Some
EXPOSE experiments investigated to what extent particular terrestrial organisms
are able to cope with extraterrestrial environmental conditions. Others tested how
organic molecules react when subjected for a prolonged period of time to unfiltered
solar light.