EFAL: EDRS Feeder Link from Antarctic Latitudes - System Architecture and Operations Concept

The goal of near real-time delivery of data from spacecraft in polar low Earth orbits to the customers can be achieved by utilization of Arctic and Antarctic hubs in a Ground Station Network. Additionally, the commanding of the satellites from these hubs can provide novel opportunities for spacecraft operations. The challenge of high-rate data repatriation from such remote sites can be met by means of laser communications from ground to geostationary satellites. We present system architecture and operations concept for a setup employing the European Data Relay System (EDRS) for data uplinks from an Antarctic ground station taking into account the impact of local atmospheric conditions

MOSFETs-based Pressure Sensors in Thin Film SOI Technology

In this paper, novel intrinsically digital pressure sensors concept is presented and successfully demonstrated. The sensors principle consists in integrating active devices, used as pressure transducers, directly on very thin dielectric membranes. A uniform thickness of 1.2-1.5 µm is obtained. Two original architecture types were designed and fabricated. The first solution implements a single NMOSFET acting as a current source which is sensitive to the sum of both components of stress (σxx+σyy) and located at the center of a membrane. Between 0.1 and 4.8 bar, the output frequency and the N-source transducer current are raised respectively of +12 % and +20 %. The sensor power consumption is 2.1 µW. The second solution is based on PMOS mirror cells. PMOSFETs are placed in opposite orientation, i.e. perpendicularly to each other, taking advantage of the opposite sign and the high value of their piezoresistive coefficients. These cells are sensitive to stress components difference (σxx-σyy). Therefore, the sensors are suspended on rectangular membranes, which provide a good stress asymmetry. Simple and double mirror cells based sensors do show a frequency output variation of +21 % and +44 %, respectively, between 0.1 and 4.9 bars