Mars Science Helicopter Conceptual Design

Robotic planetary aerial vehicles increase the range of terrain that can be examined, compared to traditional landers and rovers, and have more near-surface capability than orbiters. Aerial mobility is a promising possibility for planetary exploration as it reduces the challenges that difficult obstacles pose to ground vehicles. The first use of a rotorcraft for a planetary mission will be in 2021, when the Mars Helicopter technology demonstrator will be deployed from the Mars 2020 rover. The Jet Propulsion Laboratory and NASA Ames Research Center are exploring possibilities for a Mars Science Helicopter, a second-generation Mars rotorcraft with the capability of conducting science investigations independently of a lander or rover (although this type of vehicle could also be used assist rovers or landers in future missions). This report describes the conceptual design of Mars Science Helicopters. The design process began with coaxial-helicopter and hexacopter configurations, with a payload in the range of two to three kilograms and an overall vehicle mass of approximately twenty kilograms. Initial estimates of weight and performance were based on the capabilities of the Mars Helicopter. Rotorcraft designs for Mars are constrained by the dimensions of the aeroshell for the trip to the planet, requiring attention to the aircraft packaging in order to maximize the rotor dimensions and hence overall performance potential. Aerodynamic performance optimization was conducted, particularly through airfoils designed specifically for the low Reynolds number and high Mach number inherent in operation on Mars. The final designs show a substantial capability for science operations on Mars: a 31 kg hexacopter that fits within a 2.5 m diameter aeroshell could carry a 5 kg payload for 10 min of hover time or over a range of 5 km

Primary care-based multifaceted, interdisciplinary medical educational intervention for patients with systolic heart failure: lessons learned from a cluster randomised controlled trial

Background: Chronic (systolic) heart failure (CHF) is a common and disabling condition. Adherence to evidence-based guidelines in primary care has been shown to improve health outcomes. The aim was to explore the impact of a multidisciplinary educational intervention for general practitioners (GPs) (Train the trainer = TTT) on patient and performance outcomes. Methods: This paper presents the key findings from the trial and discusses the lessons learned during the implementation of the TTT trial. Primary care practices were randomly assigned to the TTT intervention or to the control group. 37 GPs (18 TTT, 19 control) were randomised and 168 patients diagnosed with ascertained CHF (91 TTT, 77 control) were enrolled. GPs in the intervention group attended four meetings addressing clinical practice guidelines and pharmacotherapy feedback. The primary outcome was patient self-reported quality of life at seven months, using the SF-36 Physical Functioning scale. Secondary outcomes included other SF-36 scales, the Kansas City Cardiomyopathy Questionnaire (KCCQ), total mortality, heart failure hospital admissions, prescribing, depressive disorders (PHQ-9), behavioural change (European Heart Failure Self-Care Behaviour Scale), patient-perceived quality of care (EUROPEP) and improvement of heart failure using NT-proBNP-levels. Because recruitment targets were not achieved an exploratory analysis was conducted. Results: There was high baseline achievement in both groups for many outcomes. At seven months, there were no significant mean difference between groups for the primary outcome measure (-3.3, 95%CI -9.7 to 3.1, p = 0.30). The only difference in secondary outcomes related to the prescribing of aldosterone antagonists by GPs in the intervention group, with significant between group differences at follow-up (42 vs. 24%, adjusted OR = 4.0, 95%CI 1.2-13; p = 0.02). Conclusion: The intervention did not change the primary outcome or most secondary outcomes. Recruitment targets were not achieved and the under-recruitment of practices and patients alongside a selection bias of participating GPs, prohibit definite conclusions, but the CI indicates a non-effectiveness of the intervention in this sample. We describe the lessons learned from conducting the trial for the future planning and conduct of confirmatory trials in primary care. © 2009 Peters-Klimm et al; licensee BioMed Central Ltd