Concept evaluation of Mars drilling and sampling instrument

The search for possible extinct or existing life is the goal of the exobiology investigations to be undertaken during future Mars missions. As it has been learnt from the NASA Viking, Pathfinder and Mars Exploration Rover mission, sampling of surface soil and rocks can gain only limited scientific information. In fact, possible organic signatures tend to be erased by surface processes (weathering, oxidation and exposure to UV radiation from the Sun). The challenge of the missions have mostly been getting there; only roughly one third of all Mars missions have reached their goal, either an orbit around the planet, or landing to the surface. The two Viking landers in the 1970's were the first to touch down the soil of Mars in working order and performing scientific studies there. After that there was a long gap, until 1997 the Pathfinder landed safely on the surface and released a little rover, the Sojourner. In 2004 other rovers came: the Mars Exploration Rover Spirit and a while after that, the sister rover Opportunity. These five successful landings are less than half of all attempts to land on Mars. Russia, Europe and the United States have all had their landers, but Mars is challenging. Even Mars orbit has been tough to reach by many nation's orbiters. It is then understandable that of these five successful landings, performed by National Aeronautics and Space Administration (NASA), there have not yet been very complicated mechanical deep-drilling instruments onboard. The risks to get there are great, and the risk of malfunctioning of a complicated instrument there is also high. Another reason to avoid a deep-driller from the lander payload is simply the mass constrains. A drill is a heavy piece of payload, and the mass allocations for scientific instruments are small. In the launch window of 2009, both European Space Agency (ESA) and NASA have their plans to send a rover to Mars. Both of them will include some means to analyse the subsurface material. ESA's rover, called the ExoMars rover, will carry a deep-driller onboard in its Pasteur payload. At the time of writing this thesis, an exact definition of the Pasteur drill has not yet been defined. The author of this thesis has studied the driller instruments in his past work projects and in his doctoral studies. The main focus of this thesis is to analyse the feasibility of different drill configurations to fit to the requirements of the ExoMars' Pasteur payload drill by using the information gathered from the past projects. In this thesis, the author introduces a new concept of a robotic driller, called the MASA drill. The MASA drill fulfils the needs for the drill instrument onboard the Pasteur payload. The main study in this thesis concentrates on design work of the MASA drill, as well as analysis of its operation and performance capabilities in the difficult task of drilling and sampling.reviewe

Advanced extravehicular activity systems requirements definition study. Phase 2: Extravehicular activity at a lunar base

The focus is on Extravehicular Activity (EVA) systems requirements definition for an advanced space mission: remote-from-main base EVA on the Moon. The lunar environment, biomedical considerations, appropriate hardware design criteria, hardware and interface requirements, and key technical issues for advanced lunar EVA were examined. Six remote EVA scenarios (three nominal operations and three contingency situations) were developed in considerable detail

Ultrasonically assisted penetration through granular materials for planetary exploration

Space exploration missions often use drills or penetrators to access the subsurface of planetary bodies. Protected by the conditions experienced at the surface, these regions have potentially been untouched for millennia. As such, the subsurface is a very attractive option for scientific goals, be it the search for extra-terrestrial life, to examine the history of the planet, or to utilise underground resources. However, many issues arise in such a task. Every other rocky body in our solar system possesses a surface gravity lower than our own, resulting in a lower available weight for a spacecraft to ‘push’ on a penetrating device. Add to this the low power availability and complications regarding remote operation, and this becomes a very difficult process to achieve. Mole devices which burrow through the ground whilst tethered to a surface-station to provide power and data have shown great promise in this regard. Using an internal mass to ‘hammer’ themselves into the ground, special care is required to ensure internal components are not damaged, and that they can arrive at their target depth in a reasonable period of time. There is continuous development in these types of drilling and penetrating technologies and anything that can penetrate with a lower weight-on-bit (WOB), and consume less power, could potentially be extremely useful for these situations. High powered ultrasonic vibrations have been shown to reduce operational space and forces required in cutting bones for surgery. Additionally, they have been successful in reducing WOB requirements for drilling devices through rocky substrates. To maximise penetration depth, it is often favourable to progress though granular material rather than solid rock, however this also provides its own set of problems. This work looks at applying ultrasonic vibration to penetrating probes for use in granular material, with the aim of utilising it in low gravity or low mass scenarios. Before this can be done however, the regolith used for testing must be fully characterised and consistent preparation methods established, ensuring that all other effects are accounted for. An ultrasonically tuned penetrator was designed and manufactured, and the effects it had on the surface of sand were investigated using a high-speed camera and optical microscope. It was found that regions of sand immediately surrounding the penetrator were highly fluidised, localising any deformations to a small radial distance. Penetration tests were then conducted that showed ultrasonic vibration significantly reduces the penetration forces and therefore the overhead weight required, in some cases by over an order of magnitude. A similar effect was seen in power consumption, with some instances displaying a lowered total power draw of the whole system. Experiments were then conducted in a large centrifuge to examine the trends with respect to gravity. Gravitational levels up to 10 g were tested, and the general trend showed that ultrasonic penetration efficiency indeed increased at lower gravities, suggesting that the force reduction properties would be enhanced at lower levels of g. Finally, the first steps to applying this technique as a fully-fledged penetration device were conducted. These tests oversaw combining ultrasonic vibration with the established hammering mechanism used by mole devices. Comparing this against a purely hammering penetration, it was found that the addition of ultrasonic improved performance significantly, greatly reducing the number of strikes required to reach the same penetration depth. To conclude, the work presented in this thesis shows the potential that ultrasonic vibration can have with advancing low gravity/low mass penetrating devices. Reducing both the weight and power requirements can be a huge boon to small spacecraft, and the potential use as subsurface access or anchoring devices makes it an attractive avenue for future research and development

Speleothem-based reconstruction of the palaeohydrology in the tropical western Pacific = Speläothem-basierte Rekonstruktion der Paläohydrologie im tropischen West-Pazifik

Die Monsune bilden ein immenses und dynamisches System, das den gesamten Globus umgibt und welches fast die Hälfte der Weltbevölkerung fundamental beeinflusst, sowohl in Bezug auf Wasserverbrauch, Landwirtschaft, Energie und Verkehr, als auch in Bezug auf Naturkatastrophen wie Überschwemmungen und Erdrutsche. Sie stellen gleichzeitig integrale Komponenten des Globalen Klimasystems dar, indem sie feuchte Luftmassen über große Entfernungen hinweg transportieren und die mächtigsten Niederschlagssysteme der Erde speisen. Trotz ihrer Bedeutung sind die Monsune noch nicht vollständig verstanden, insbesondere hinsichtlich globaler Erwärmung, und Klimamodelle müssen verbessert werden, um dieses Problem zu lösen. Um die Verbesserung von Klimamodellen zu unterstützen und das Verständnis der Monsundynamik in Südostasien zu vertiefen, fokussiert Teil 1 dieser Thesis auf die Generierung hochqualitativer Paläodaten aus zwei Stalagmiten aus zwei Höhlen in Nordvietnam, innerhalb der Übergangszone zwischen dem Indischen Sommermonsun (ISM) und dem Ostasiatischen Sommermonsun (EASM), aus welcher Paläodaten immer noch kaum vorhanden sind. Für die Rekonstruktion der lokalen und regionalen Klimabedingungen während der letzten 8.000 Jahre des Holozäns und während des Übergangs von dem Heinrich Stadial 1 zu der Bølling-Allerød Warmphase (16.2 – 13.4 ka BP) wird in dieser Thesis ein Multiproxyansatz angewendet, welcher die stabilen Isotope von Sauerstoff und Kohlenstoff, Spurenelemente sowie Kristallmorphologie-Typen kombiniert, in Verbindung mit einem Multiparameter-Monitoring der heutigen Höhlenumgebung. Die Ergebnisse spiegeln die Variabilität des Asiatischen Sommermonsuns (ASM) innerhalb der Übergangszone zwischen ISM und EASM auf sub-orbitaler Zeitskala bis zur Zeitskala von Jahrhunderten wider, in Übereinstimmung mit veröffentlichten Proxyaufzeichnungen aus Stalagmiten, anderen Umweltarchiven sowie Ergebnissen von Modellsimulationen. Die Multiproxyergebnisse werden vorrangig im Sinne von lokaler bis supra-regionaler Wasserverfügbarkeit und atmosphärischer Zirkulation interpretiert und unterstreichen die Bedeutung des ISM als Initiator des berühmten und kontrovers diskutierten δ18O-Signals in chinesischen Stalagmiten. Unter Berücksichtigung der neuen Multiproxy-Paläodaten scheint der Mechanismus des luvseitigen Ausregnens (upstream rainout mechanism) der wichtigste Prozess zu sein, welcher das supra-regionale Muster von Stalagmit-basierten δ18O-Aufzeichnungen erschafft, welches in den letzten zehn Jahren zutage getreten ist. Zudem wird basierend auf diesen neuen Daten die Hypothese aufgestellt, dass der Niederschlag, der die chinesischen Stalagmiten gebildet hat, einen signifikanten Anteil an isotopisch schwerem Regen hat, welcher sich wahrscheinlich aus einer nähergelegenen Quelle speist, etwa aus dem Chinesischen Meer. Die neuen Daten zu Kohlenstoffisotopen und Spurenelementen spiegeln lokale Schwankungen in der Wasserverfügbarkeit wider, sowie Ereignisse besonders hoher Infiltration und/oder Höhlenüberflutungen, welche damit in dieser Region zum ersten Mal rekonstruiert werden. Die Interpretation von Proxysignalen aus Speläothemen, wie in Teil 1 dieser Thesis durchgeführt, kann vereinfacht und verbessert werden, indem die heutigen Umwelt-Rahmenbedingungen in Bezug auf die Speläothembildung an dem jeweiligen Untersuchungsort in mehrjährigen Monitoring-Studien untersucht werden. Von besonderem Interesse ist hierbei die isotopische und geochemische Zusammensetzung des Tropfwassers, welches die Speläotheme bildet, die für die Generierung der geochemischen Zeitreihen aus Paläodaten verwendet werden. Um die fundamentale Verknüpfung zwischen Veränderungen dieser Proxysignale im Tropfwasser und den entsprechenden Schwankungen in deren natürlichen Auslösern wie etwa Niederschlag und Höhlenbelüftung herzustellen, müssen Tropfwässer über mehrere Monate bis Jahre wiederholt beprobt werden. Die wiederholte händische Tropfwasserbeprobung ist jedoch nicht nur zeitaufwänding, sondern auch teuer und logistisch anspruchsvoll, vor allem in weit entlegenen Gebieten mit schlechter oder ohne Infrastruktur – in denen sich die meisten Karsthöhlen befinden. Da dieses Problem nur durch Automatisierung gelöst werden kann, wurden im Rahmen dieser Thesis zwei automatische Tropfwasser-Probenehmer entwickelt, sie werden in Teil II dargestellt und diskutiert. Eine erste erfolgreiche Fallstudie unter Einsatz des zweiten Probenehmer-Prototypen zeigt den technischen Wert des Geräts selbst auf sowie den wissenschaftlichen Nutzen der Daten, die der automatische Probenehmer zugänglich macht. Zum ersten Mal wurde die Beziehung zwischen hochfrequenten Schwankungen der CO2-Konzentration in der Höhlenluft auf Zeitskalen von unter einem Tag und den daraus resultierenden hoch-frequenten Änderungen in den δ13CDIC-Werten (DIC = gelöster anorganischer Kohlenstoff) im Tropfwasser hergestellt und quantifiziert. Diese Beziehung hat wichtige Implikationen für die Speläothemforschung im Allgemeinen und die Interpretation von δ13C-Aufzeichnungen in Speläothemen im Besonderen

Viking '79 Rover study. Volume 2: Detailed technical report

For abstract, see N74-19888

Concepts and Approaches for Mars Exploration

Abstracts describe missions, mission elements or experiments for consideration in the 2005-2020 time frame. Also the technologies and the support necessary to achieve the results are discussed.NASA Headquarters; Lunar and Planetary Institutehosted by Lunar and Planetary Institute ; sponsored by NASA Headquarters, Lunar and Planetary Institute ; convener Scott Hubbard

ESSE 2017. Proceedings of the International Conference on Environmental Science and Sustainable Energy

Environmental science is an interdisciplinary academic field that integrates physical-, biological-, and information sciences to study and solve environmental problems. ESSE - The International Conference on Environmental Science and Sustainable Energy provides a platform for experts, professionals, and researchers to share updated information and stimulate the communication with each other. In 2017 it was held in Suzhou, China June 23-25, 2017