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Dr Craig Pitcher


My publications

Publications

Gao Y, Frame TED, Pitcher Craig (2015) Peircing the extraterrestrial surface: Integrated robotic drill for planetary exploration,IEEE Robotics and Automation Magazine22(1)pp. 45-53 IEEE
As we explore our solar system and other extraterrestrial bodies, the subsurface plays a vital role in allowing us to peer back into the history of a particular body, looking for life or signs that it may have been habitable. This can be achieved by using a form of drill or penetrator, although traditional technologies require large masses to produce an overhead force (OHF) that pushes the drill into the subsurface. Dual reciprocating drilling (DRD) is a new biologically inspired technology based on the wood wasp ovipositor. It consists of two reciprocating backward-facing teethed halves that generate a drilling force that reduces the required overhead penetration force and mass requirements. The Surrey Space Centre (SSC) has overseen the design, development, and testing of a proof-of-concept model with funding from European Space Agency. The system is now evolving to include a drive mechanism within the drill head and bays for scientific instrumentation.
Pitcher Craig, Gao Yang (2015) Analysis of drill head designs for dual-reciprocating drilling technique in planetary regoliths,Advances in Space Research56(8)pp. 1765-1776 Elsevier
© 2015 COSPAR. The dual-reciprocating drill (DRD) is a biologically-inspired concept which has shown promise in planetary environments, requiring a lower overhead force than traditional rotary drilling techniques. By using two reciprocating backwards-facing teethed halves to grip the surrounding substrate, it generates a traction force that reduces the required overhead penetration force. Research into DRD has focused on the effects of operational and substrate parameters on performance compared to static penetration, with minimal study of the geometrical parameters which define the drill head. This paper presents the exploration of the effects of drill head design on drilling depth and power consumption. Sixteen variations of the original design were tested in planetary regolith simulants up to depths of 800. mm. The experiments showed relationships between final depth, total drill radius and cone shape, though the teeth design had a negligible effect on performance. These results can be used alongside the previous research to optimise the future design and operation of the DRD. Drill stem bending was seen to cause an increase in drilling speed and depth, leading to the exploration of the mechanics of diagonal drilling. This resulted in the proposal of a fully-integrated system prototype that incorporates both reciprocating and lateral motion mechanisms.
Kömle Norbert I., Tiefenbacher P, Pitcher Craig, Richter Lutz, Tattusch Tim, Paul Robert (2019) Sampling of Mars analogue materials in a laboratory environment,Acta Geotechnica14(2)pp. 429-442 Springer Berlin Heidelberg
Two laboratory test series were performed with the aim of ensuring the proper functionality of the key sampling mechanisms installed aboard the Mars rover ExoMars, currently scheduled for launch in 2020 by the European Space Agency ESA. In order to facilitate the chemical analysis of the Martian ground accessible to the ExoMars drill, the retrieved drill cores must first be milled. This task is performed by a crushing station (CS), which delivers the milled product to a dosing device (PSDDS). From there the material is distributed further to the various analysis instruments mounted on the rover. The first test series was performed with a mock-up of crushing station and dosing device under simulated Martian pressure and temperature conditions. As a worst-case scenario, crushing of frozen soil mixtures was performed and the milling products were collected in the dosing station before being further distributed. In the second test series, granular analogue materials equivalent to the milled products obtained in previous tests were stored for periods of several days in the input funnel of the dosing device. The set-up included a regulation valve through which water vapour was streamed into the vacuum chamber to create a water vapour-saturated atmosphere. The purpose of this series of tests was to investigate if the presence of water can cause cementation of the samples, and how this subsequently affects the operation of the crushing and distribution devices. Our results indicate that the milling device works very well with the current design both for loose and for hard block-like materials, e.g., chunks of frozen soil. It was also found that milled material, when subjected to a water-saturated atmosphere, does not experience any cementation.
Pitcher Craig, Kömle N, Leibniz O, Morales-Calderon O, Gao Yang, Richter L (2016) Investigation of the properties of icy lunar polar regolith simulants,Advances in Space Research57(5)pp. 1197-1208 Elsevier
As icy regolith is believed to exist in the subsurface of permanently shadowed areas near the lunar south pole, there is a growing interest in obtaining samples from these polar regions. To qualify for spaceflight, sampling instruments must demonstrate their ability to operate in the expected environment. However, there is currently no quantitative data detailing the extent and distribution of ice in polar regolith. While work has been done to determine the effects of water ice content in simulants such as JSC-1A, to date there has been no investigation into the properties of icy simulants of the regolith believed to be found at lunar polar regions. A series of experiments has therefore been conducted to determine the properties of icy NU-LHT-2M lunar highland simulant, an approximation of lunar polar regolith, at varying degrees of saturation. A number of procedures for preparing the simulant were tested, with the aim of defining a standardised technique for the creation of icy simulants with controlled water contents. Saturation of the highland simulant was found to occur at a water mass content between 13% and 17%, while cone penetration tests demonstrated that a significant increase in penetration resistance occurs at 5 ± 1%. Uniaxial compression tests showed an increase in regolith strength with water mass and density, which slows down as the saturation level is reached. The results presented here demonstrate the first characterisation of the properties of icy lunar polar regolith simulants, which can be expanded upon to further the understanding of its properties for use in future instrumentation testing.
Urbina Diego A., Gancet Jeremi, Kullack Karsten, Ceglia Enrico, Madakashira Hemanth K., Salini Joseph, Govindaraj Shashank, Surdo Leonardo, Aked Richard, Sheridan Simon, Pitcher Craig, Barber Simeon, Biswas Janos, Reiss Philipp, Rushton Joseph, Murray Neil, Evangora Anthony, Richter Lutz, Dobrea Diana, Reganaz Mattia LUVMI: an innovative payload for the sampling of volatiles at the Lunar poles,Proceedings: 68th International Astronautical Congress 2017
The International Space Exploration Coordination Group (ISECG) identifies one of the first exploration steps as in situ investigations of moon or asteroids. Europe is developing payload concepts for drilling and sample analysis, a contribution to a 250kg rover as well as for sample return. To achieve these missions, ESA depends on international partnerships. Such important missions will be seldom, expensive and the drill/sample site selected will be based on observations from orbit not calibrated with ground truth data. Many of the international science communitys objectives can be met at lower cost, or the chances of mission success improved and the quality of the science increased by making use of an innovative, low mass, mobile robotic payload following the Lunar Exploration Analysis Group (LEAG) recommendations. The LUnar Volatiles Mobile Instrumentation (LUVMI) provides a smart, low mass, innovative, modular mobile payload comprising surface and subsurface sensing with an in-situ sampling technology capable of depth-resolved extraction of volatiles, combined with a volatiles analyser (mass spectrometer) capable of identifying the chemical composition of the most important volatiles. This will allow LUVMI to: traverse the lunar surface prospecting for volatiles; sample subsurface up to a depth of 10 cm (with a goal of 20 cm); extract water and other loosely bound volatiles; identify the chemical species extracted; access and sample permanently shadowed regions (PSR). These payload characteristics of LUVMI will permit to maximize sample transfer efficiency and minimize sample handling as well its attendant mass requirements and risk of sample alterations. By building on national, EC and ESA funded research and developments, this project will develop to TRL6 instruments that together form a smart modular mobile payload that could be flight ready in 2020. The LUVMI sampling instrument will be tested in a highly representative environment including thermal, vacuum and regolith simulant and the integrated payload demonstrated in a representative environment.
Gancet Jeremi, Urbina Diego, Kullack Karsten, Reiss Philipp, Biswas Janos, Sheridan Simon, Barber Simeon, Murray Neil, Rushton Joseph, Richter Lutz, Dobrea Diana, Salini Joseph, Madakashira Hemanth Kumar, Govindaraj Shashank, Aked Richard, Surdo Leonardo, Ceglia Enrico, Pitcher Craig, Evagora Anthony, Reganaz Mattia LUVMI: A concept of low footprint lunar volatiles mobile instrumentation,Proceedings ASTRA - 14th Symposium on Advanced Space Technologies in Robotics and Automationpp. 1-8 The European Space Agency (ESA)
The International Space Exploration Coordination Group (ISECG) identifies one of the first exploration steps as in situ investigations of the Moon or asteroids. Europe is developing payload concepts for drilling and sample analysis, a contribution to a 250kg rover as well as for sample return. To achieve these missions, ESA depends on international partnerships. Such missions will be seldom, expensive and the drill/sample site selected will be based on observations from orbit not calibrated with ground truth data. Many of the international science community?s objectives can be met at lower cost, or the chances of mission success improved and the quality of the science increased by making use of an innovative, low mass, mobile robotic payload following the LEAG recommendations. As a main objective LUVMI is designed specifically for operations at the South Pole of the Moon with a payload accommodated by a novel lightweight mobile platform (rover) with a range of several kilometers. Over the 2 years duration of the project, the scientific instruments payload will be developed and validated up to TRL 6. LUVMI targets being ready for flight in 2020 on an ESA mission partially supported by private funding.