The aim of the research documented in this thesis was to explore issues associated with thedevelopment of instrumentation for life detection and characterisation in a planetary explorationcontext.Within this aim, the following objectives had to be achieved:1. To consider current and near-future single molecule detection (ultra-low lower limit ofdetection) analytical techniques that would be compatible with development into a Spacequalifiable in situ analytical instrument for the detection of biomarkers in a planetaryexploration context.2. To practically consider the consequences of Planetary Protection and Contamination Controlon the development of a sample return instrumentation in a planetary exploration context.3. To consider the implications of flying an in situ instrument on-board a stratospheric balloonplatform in order to apply them into a specific planetary exploration mission:In order to achieve the objectives described above, the following work was pursued: A desk-based European Space Agency (ESA) study was carried out which entailed producing aliterature review on single molecule detection technologies that had to be validated by theexpert community. This was done by organising an International Workshop on Single MoleculeDetection Technologies for Space Applications in March 2009 at Cranfield University, UK. Theapproved technologies then had to be analysed with standard analytical techniques (i.e., tradeoffs)in order to propose a specific technology for development and present its breadboardimplementation and test plans at the end of the study. A sample return experiment implementing PP&CC constraints and protocols was designed,built, tested and flown on-board the ESA, Swedish Space Corporation (SSC), Swedish NationalSpace Board (SNSB) and German Space Agency (DLR) BEXUS stratospheric balloon platform.The biological and engineering results obtained from the sample return flight were thenanalysed and lessons learnt obtained for future flights. Another desk-based study was performed to research future stratospheric balloon platforms forthe exploration of Venus’ cloud layer. The in situ instrument previously proposed for thedetection of biomarkers for planetary exploration missions was then put forward as a possiblepayload for a Venusian stratospheric balloon platform and approved by experts during theVenus Exploration Analysis Group (VEXAG) conference held in August 2011 in WashingtonD.C, USA.The first part of the research involved studying ultra-low lower limit of detection technologies asthese have the potential to impact significantly on the technological and scientific requirements offuture Space missions. Two systems were proposed: one based on Tandem Mass Spectrometry(with Cylindrical Ion Trap analysers) followed by Surface Enhanced Raman Scatteringspectroscopy to create an MS/MS-SERS instrument for the detection of astrobiology biomarkers inMartian regolith, Europan ice and samples from Titan’s hydrocarbon lakes; and a second one as aStand-Alone SERS system for the detection of biomarkers in Enceladean plumes, Venusian cloudsand cometary coma.The second part of the research practically explored the design of instrumentation for stratosphericballoon platforms. CASS•E, the Cranfield Astrobiological Stratospheric Sampling Experiment, wasa life detection experiment that aimed to be capable of detecting stratospheric microorganisms.The experiment consisted of a pump which drew air from the Stratosphere through a 0.2 μmcollection filter which retained any microorganisms and >0.2 μm particulates present in the pumpedair. Due to the expected rarity of microbes in the Stratosphere compared to the known levels ofcontamination at ground level, Planetary Protection and Contamination Control (PP&CC)constraints were introduced. Therefore PP&CC protocols were followed to implement Spacequalified cleaning and sterilisation techniques; biobarrier technology was implemented to preventre-contamination of the instrument after sterilisation; and cleanliness and contamination wasmonitored throughout assembly, integration and testing.The third part of the research demonstrated how an instrument from the first part of the study couldbe proposed as a payload on-board a stratospheric balloon platform with a focused missioncontext, i.e., a life detection mission for Venus. Therefore, the research concluded with theproposal of a payload for a Venus mission based on SERS technology on-board a stratosphericballoon platform to search for life above or in the mid Venusian cloud cover.
展开▼
