This MSc diploma thesis work in Space Engineering has been performed at the
NASA Jet Propulsion Laboratory, where one of the projects included the
construction and development of a hydrothermal vent bio-sampler. On the
bottom of the oceans with volcanic activity, hydrothermal vents can be
found which spew out mineral-rich superheated water from the porous
seafloor crust. Some of these vents are situated several thousand meters
below the surface, where sunlight never reaches. Yet life thrives there on
the minerals and chemical compounds, which the vent water brings up with
it. This chemosynthetic microbial community forms the basis of some of the
most interesting ecosystems on our planet, and could possibly also be found
on other water-rich planets and moons in the solar system. Perhaps
hydrothermal vents exist under the icy surface of the moon Europa with a
biota thriving independently of the solar energy.
The Hydrothermal Vent Bio-sampler (HVB) will be a system to collect
pristine samples of the water emanating from subsurface hydrothermal vents.
An array of temperature and flow sensors will monitor the sampling
conditions, which will allow for the samples to be collected from defined
locations within the vent plume. From this the diversity and distribution
of the chemosynthetic communities, which might live there, can be
accurately described. The samples will have to be taken without any
contamination from the surrounding water, thus the pristine requirement.
Monitoring the flow will assure that enough water has been sampled to
account for the low biomass of these environments. The system will use a
series of filters, down to 0.2 micrometer in pore size, and the samples can
be directly collected from the system for both culture- and molecular-based
biological analyses. The HVB now in its development and testing phase, is
designed to operate under the extreme conditions at the bottom of the
oceans by the hydrothermal vents. This means that the system needs to
handle temperatures of up to 400 degrees Celsius and pressures
corresponding to the depth of about 7000 km below the ocean surface.
After testing at a hydrothermal vent system in the Eyjafjördur fjord off
the coast of Iceland the previous year, modifications and improvements were
made to the HVB. This system has, amongst others, now successfully passed
the pressure test at Scripps Institution of ...
