Investigation and modelling of large scale cratering events : Lessons learnt from experimental analysis

Initiated as part of the 2010 Spin Your Thesis campaign, a new ESA Education programme, a group from the University of Glasgow Space Advanced Research Team successfully conducted a series of impact cratering experiments under a highly accelerated reference frame. This aimed to: reproduce and define the physical conditions of large-scale cratering events onto highly porous asteroids; provide cratering response data for the validation and advancement of numerical models; and support the generation of a reliable scaling theory for cratering events. Impact cratering is a fundamental process that has shaped and continues to shape the formation and evolution of our solar system and other planetary systems. Although much is known on the impact dynamics of rocky, brittle bodies, such as asteroids, little is known on the physical response of highly porous bodies. Consequently the physical response of porous bodies can not be compared to conventional models. Therefore throughout the experiment campaign, variation into the target material’s porosity and projectile density was examined. All in-situ measurements were recorded relative to the crater’s morphological profile and ejecta distribution. This occurred under increasing levels of acceleration, thereby validating that the experiment occurred within the crater dominated gravity regime. This paper details the programmatics issues of the initiative, experiences and lessons learnt from the student perspective. From its initial proof-of-concept the Spin Your Thesis campaign provided a solid foundation from the development of an experimental idea, enabling high scientific return and personal development

Optimal options for rendezvous and impact missions to NEOs

In this paper some potentially interesting transfer options for missions to Near Earth Objects have been studied. Due to thehigh number of potential targets and to the large variety of possible missions that can be considered, especially if resorting to low-thrust propulsion, an extensive analysis of transfer options requires a preliminary approach oriented toward an effective global search, and an appropriately simplified trajectory transcription. Low-thrust options have been modeled through a novel shape-based approach and a global optimization method has been used to look for globally optimal transfers. Different targets have been identified and various mission scenarios have been considered: rendezvous, sample return missions both with and without Earth gravity assist and impact missions

Cutaneous Manifestations in Inflammatory Bowel Diseases

Inflammatory bowel diseases have a high frequency in Europe. They are chronic disorders that evolve with relapses and remissions. Clinical features include the signs of underlying inflammatory bowel disease and also signs of extraintestinal manifestations. Cutaneous disorders are the most common extraintestinal manifestations associated with inflammatory bowel diseases, which can be dependent on or independent of gastrointestinal disease activity. The main cutaneous disorders are erythema nodosum and pyodermagangrenosum. The pathogenic mechanisms are not fully understood but it seems that related mechanisms are involved in the development of inflammatory bowel diseases and extraintestinal manifestations. Treatment should be aimed at both the cutaneous manifestations and the bowel inflammation

Orbital debris removal with solar concentrators

In 1993 solar concentrators were first proposed to deflect asteroids away from a collision course with the Earth. The original concept was expanded by the authors, and proved to be effective and technologically feasible. One way to deflect the asteroid is to produce a slow decay of its orbit by inducing a thrust via concentrated solar light. Two mechanisms have been investigated: the sublimation of the surface of the asteroid to generate a jet of gas and the induced thrust by light pressure and enhanced Yarkovsky effect. If the concentrators are reduced in size, a similar concept can be adopted to remove orbital debris and inert satellites. In this paper, we present an orbital debris removal system based on concentrated solar light. We will show how enhanced solar pressure, generated by a formation of solar concentrators, can be used to accelerate the decay of small inert objects orbiting the Earth. A set of modified proximal motion equations is proposed to describe the relative dynamics of the solar concentrators with respect to the target piece of debris. The paper will provide an analysis of the cost of the optimal control of the concentrators during the deflection of the debris and a system engineering analysis. In particular, we will show that the concentrator acts as an active solar sail while not deflecting, and as a hybrid solar sail (i.e. the orbit is maintained with an auxiliary low-thrust engine) while deflecting the debris. The results will show that objects with even a small area-to-mass ratio (down to 0.01) can be brought from an 800 km to a 200 km altitude orbit in few hundred days of constant operation. The paper will discuss also the possibility to vaporize some small size targets with high power solar pumped laser

Time-optimal trajectories to circumsolar space using solar electric propulsion

The aim of this paper is to explore the capabilities of a solar electric propelled spacecraft on a mission towards circumsolar space. Using an indirect approach, the paper investigates minimum time of transfer (direct) trajectories from an initial heliocentric parking orbit to a desired final heliocentric target orbit, with a low perihelion radius and a high orbital inclination. The simulation results are then collected into graphs and tables for a trade-off analysis of the main mission parameters. Finally, a comparison of the performance between a solar electric and a (photonic) solar sail based spacecraft is discussed

Imatinib-induced interstitial pneumonitis – a literature review and case report

Imatinib is generally well tolerated, with mild common side effects such as nausea and vomiting, diarrhea, muscle cramps, fatigue, skin rash and edema; however, pulmonary complications are uncommon. A 73-year-old woman undergoing one month treatment with Imatinib for chronic myeloid neoplasm associated with eosinophilia was admitted for sudden alteration of her performance status, dyspnea at rest and productive cough. On clinical examination, the patient was hypoxic (oxygen saturation on room air was 87%), and auscultation of her lungs revealed diffuse bilateral fine crackles. Computed tomography showed bilateral pulmonary interstitial syndrome. Imatinib was discontinued and the patient received systemic corticosteroid therapy and oxygen therapy. After one month, the symptoms and radiological findings were resolved. When Imatinib therapy was resumed, respiratory symptoms reappeared, which is why treatment with Imatinib was interrupted. Imatinib-induced pneumonitis should take into consideration when patients develop respiratory symptoms or abnormal pulmonary radiological features