Flight and Direct to Earth/Space Relay Communication System Architecture for GSFC CubeSat Missions

The CubeSat platform is finding increasing use in space science applications due to its low cost and comparative ease of launch. It is becoming a key scientific discovery tool in low Earth orbit (LEO) and beyond, including geosynchronous equatorial orbit (GEO), the Lagrange Points, Lunar missions, and more. The increasing complexity of these missions and their scientific goals must be supported by equal advancements in communications technology. Higher data rates and greater reliability are required every year. However, the reduced Size, Weight, and Power (SWaP) constraints of CubeSat platforms introduce unique challenges in the area of satellite communications. There is currently a lack of communication equipment tailored specifically to the CubeSat platform. This lack of standardized, tested equipment extends development time and reduces mission confidence. Furthermore, missions utilizing the CubeSat platform are often subject to more difficult design constraints. Antenna placement, size, and pointing are often subordinate to the requirements of the payload instruments and mission goals. Traditional link margin estimation techniques are insufficient in these cases, as they emphasize worst case scenarios. In reality the actual link parameters may vary widely even during a single pass. This presents new challenges in predicting communications performance and scheduling ground station contacts, but also new opportunities for improving efficiency. This paper presents the integration, testing, and validation process for a new software defined radio (SDR) designed for the CubeSat platform in conjunction with Vulcan Wireless, Inc. The SDR is planned for use on 5 upcoming CubeSat missions at NASAs Goddard Space Flight Center (GSFC) including a Geosynchronous Transfer Orbit (GTO) mission and it may also serve as a standard and well-tested option for future missions by enabling a standardized, rapid and low cost CubeSat communication system network integration process. Detailed simulations have been developed to estimate the communication performance of these missions, taking the unique antenna placements and attitude behavior of each satellite into account. These simulations allow a much more accurate analysis of the expected link margin, which varies considerably during each pass for the NASA Space Relay (SR) and Direct to Earth (DTE) network. The modelling procedures are outlined, and the results are used to predict communications performance of the missions

Multiple osteochondroses of bilateral knee joints: a case report

Knee injuries in young athletes include not only the typical adult bone injuries, ligament and cartilage, but also the growth plate lesions. Osteochondroses are idiopathic, self-limited disturbance of enchondral ossification in which a rapid growth spurt is present. The patella could be affected by two different kinds of osteochondroses: Kohler syndrome and Sinding-Larsen-Johansson. Here we are reporting the first case of simultaneous location of ostechondroses of the two ossification centers of both patella. A 9-year-old boy, competitive skater, presented a history of anterior knee pain involving both knees. Standard X-rays, axial patellar view, MRI and arthro-MR were performed. In order to follow the natural history of the pathology and the evolution of the healing, examinations at 2 years were repeated. We proposed the young skater a medical and a physiotherapeutic treatment based on unloading, isometric exercises, NSAID. As the symptoms improve a gradual return to competitive sports activity was allowed. The case mentioned above can be considered an atypical case because the patient suffered for a bilateral knee osteochondroses, involving simultaneously the primary ossification centre (Kohler syndrome) and the secondary ossification centre (Larsen syndrome) of the patella

Plasma cortisol concentrations and lifestyle in a population of outdoor workers

The aim of this study was to assess whether exposure to urban pollution in outdoor workers, may alter plasma cortisol concentrations also in relation to the effect of smoking and drinking habits. The research was carried out on 498 outdoor police workers, divided into three groups; Group A: traffic policemen (TP), Group B: drivers (D), Group C: Other duties (OD). To evaluate separately the effect of using alcohol and smoking, each group was divided into three subgroups: (1) non-smokers and non-drinkers, (2) smokers and non-drinkers, (3) non-smokers and drinkers. Our results show cortisol mean values were significantly higher in the TP group compared to the D and OD groups without significant differences between the last two groups. The results suggest that exposure to pollutants associated with urban psychosocial stress may play a more important role on plasma cortisol levels than smoking and alcohol

Overweight and urban pollution: preliminary results

The aim of this study is to determine whether in workers exposed to urban pollution the risk of developing overweight and obesity is higher in workers exposed to urban pollution compared to a control group. The study was conducted on 150 volunteers, 75 workers exposed to urban pollution (50 women and 25 men) and 75 indoor workers (50 women and 25 men). Once measured the weight and height and calculated body mass index (BMI) for each worker, the research was based on the comparison, between the two groups, of the mean values of the measurements and of the frequency of workers with BMI index higher than the cut-off of normality. The only statistically significant difference found was for the mean value of weight in women, which was higher among outdoor workers compared to indoor workers. The mean values of BMI and the frequency of workers with BMI higher than normal was higher among outdoor workers compared to indoor workers in both sexes, but not statistically significant. The data suggest that outdoor workers may be subject to an additional risk of developing obesity as a result of exposure to urban air pollution (which, like obesity, is a source of oxidative stress). So, our preliminary study encourages to continue this line of research by implementing the sample and considering all the confounding factors. Furthermore, the results highlight the necessity to take account of gender differences in the context of health surveillance of workers

Follicle-stimulating hormone levels in female workers exposed to urban pollutants

The aim of this study was to evaluate if there were alterations in FSH plasma levels in female outdoor workers (traffic policewomen and drivers) exposed to chemical urban stressors vs. control group. After excluding subjects with main confounding factors, traffic policewomen, drivers and indoor workers were matched by age, working life, socioeconomic status, marital status, menstrual cycle day, age of menarche, habitual consumption of Italian coffee and soy. A total of 129 female subjects were included in the study: Some 63 workers studied during proliferative phase and 66 during secretory phase of menstrual cycle. Proliferative phase of menstrual cycle: FSH mean values were significantly higher in traffic policewomen compared to controls (p < 0.05). Results suggest that in outdoor workers exposed to urban chemical stressors there are alterations in FSH levels; therefore FSH may be used as an early biological marker, valuable for the group, used in occupational set

Rapid response to the earthquake emergency of May 2012 in the Po Plain, northern Italy

Rapid-response seismic networks are an important element in the response to seismic crises. They temporarily improve the detection performance of permanent monitoring systems during seismic sequences. The improvement in earthquake detection and location capabilities can be important for decision makers to assess the current situation, and can provide invaluable data for scientific studies related to hazard, tectonics and earthquake physics. Aftershocks and the clustering of the locations of seismic events help to characterize the dimensions of the causative fault. Knowing the number, size and timing of the aftershocks or the clustering seismic events can help in the foreseeing of the characteristics of future seismic sequences in the same tectonic environment. Instrumental rapid response requires a high degree of preparedness. A mission in response to a magnitude (ML) 6 event with a rupture length of a few tens of kilometers might involve the deployment within hours to days of 30-50 seismic stations in the middle of a disaster area of some hundreds of square kilometers, and the installation of an operational center to help in the logistics and communications. When an earthquake strikes in a populated area, which is almost always the case in Italy, driving the relevant seismic response is more difficult. Temporary station sites are chosen such as to optimize the network geometry for earthquake locations and source study purposes. Stations have to be installed in quiet, but easily reachable, sites, and for real-time data transmission, the sites might need to have optical intervisibility. The operational center can remain in a town if there is one within the damaged area, and it should coordinate the actions of the field teams and provide information to colleagues, the Civil Protection Authorities and the general public. The emergency system should operate as long as the seismic rate remains high; the duration of any mission might also depend on the seismic history of the area involved. This study describes the seismic response following the May 20, 2012, ML 5.9 earthquake in northern Italy, which included rapid deployment of seismological stations in the field for real-time seismic monitoring purposes, the coordination of further instrumental set-ups according to the spatial evolution of the seismic sequence, and data archiving