The shadow position sensors (SPS) formation flying metrology subsystem for the ESA PROBA-3 mission: present status and future developments

PROBA-3 [1] [2] is a Mission of the European Space Agency (ESA) composed of two formation-flying satellites, planned for their joint launch by the end of 2018. Its main purposes have a dual nature: scientific and technological. In particular, it is designed to observe and study the inner part of the visible solar corona, thanks to a dedicated coronagraph called ASPIICS (Association of Spacecraft for Polarimetric and Imaging Investigation of the Corona of the Sun), and to demonstrate the in-orbit formation flying (FF) and attitude control capability of its two satellites. The Coronagraph payload on-board PROBA-3 consists of the following parts: the Coronagraph Instrument (CI) with the Shadow Position Sensor (SPS) on the Coronagraph Spacecraft (CSC), the Occulter Position Sensor (OPSE) [3] [4] and the External Occulting (EO) disk on the Occulter Spacecraft (OSC). The SPS subsystem [5] is one of the main metrological devices of the Mission, adopted to control and to maintain the relative (i.e. between the two satellites) and absolute (i.e. with respect to the Sun) FF attitude. It is composed of eight micro arrays of silicon photomultipliers (SiPMs) [6] that shall be able to measure, with the required sensitivity and dynamic range as asked by ESA, the penumbral light intensity on the Coronagraph entrance pupil. With the present paper we describe the testing activities on the SPS breadboard (BB) and Development Model (DM) as well as the present status and future developments of this PROBA-3 metrological subsystem

Comparison of the efficacy of rosuvastatin versus atorvastatin in reducing apolipoprotein B/apolipoprotein A-1 ratio in patients with acute coronary syndrome: Results of the CENTAURUS study

Background. The mechanism underlying statin-induced event reduction in patients with acute coronary syndrome remains unclear. Aims. To assess the efficacy of rosuvastatin 20 mg versus atorvastatin 80 mg in reducing the apolipoprotein B/apolipoprotein A-1 (apoB/apoA-1) ratio at 3 months. Non-inferiority of rosuvastatin 20 mg versus atorvastatin 80 mg in reducing low-density lipoprotein cholesterol at 1 and 3 months was also assessed. Methods. Patients with non-ST-elevation acute coronary syndrome were enrolled into this randomized, double blind, parallel-group trial. Results. In total, 753 patients (369, rosuvastatin 20 mg; 384, atorvastatin 80 mg) were included in the intention-to-treat analysis; 478 patients (226, rosuvastatin 20 mg; 252, atorvastatin 80 mg) were included in the per-protocol analysis. Rosuvastatin 20 mg was more effective than atorvastatin 80 mg in decreasing apoB/apoA-1 ratio at 1 month (-44.4% vs -42.9%, p = 0.02) but not at 3 months (both -44.4%, p = 0.87). Low-density lipoprotein cholesterol decreased by similar to 50% after 1 and 3 months in both groups. Non-inferiority of rosuvastatin 20 mg versus atorvastatin 80 mg was demonstrated at 1 month (difference, -0.3% [95% confidence interval, -2.7; +2.1]), but not at 3 months (+1.0% [-1.6; 3.5]) (intention-to-treat analysis). In the per-protocol analysis, non-inferiority of rosuvastatin 20 mg was demonstrated at both 1 (-0.7% [-3.5; 2.0]) and 3 (-0.5% [-3.5; 2.5]) months. Conclusion. In patients with non-ST-elevation acute coronary syndrome, rosuvastatin 20 mg decreased apoB/apoA-1 ratio at 1 month more than atorvastatin 80 mg. No difference could be shown at 3 months; thus, the primary endpoint was not met. (C) 2010 Published by Elsevier Masson SAS