EUROPEAN ASTRIX~(TM) FOG IN-ORBIT HERITAGE

摘要

In the early 2000s, ASTRIUM SAS, in collaboration with iXBlue (formerly IXSEA), a French SME, developed with CNES and ESA support, an inertial reference unit (IRU) family for a wide range of space applications. These fully European products, called "ASTRIXTM", are based on solid-state (FOG) technology. The first flight models were delivered in 2006 and 2007, and production is now running smoothly. These IRUs have been selected by a range of applications as varied as PLANCK, PLEIADES, AEOLUS, GAIA, EUROSTAR, GALILEO IOV, SENTINEL 1&2, JPSS_1 etc. covering the different orbit types (LEO, MEO, GEO and Lagrange). They fully benefit from the unequalled potential of FOG technology and from its particularly good suitability to high performance space applications requirements. The ASTRIX family currently comprises three fully qualified products, namely ASTRIX200, ASTRIX120 and ASTRIX120HR, which are shortly presented in this paper. A total of 22 FOG channels, cumulating to date 170 000 operating hours, are currently in orbit (latest being with PLEIADES ASTRIX200 launched on Soyouz, Kourou, on Dec. 11). Up to Feb. 2012, the PLANCK (L2) ASTRIX 120 has continuously been in operation for two and half years and the COMS (GEO) ASTRIX 120HR for one and half year. After having briefly introduced the origin of the product development, the paper presents the observed in-orbit performances of these gyros in detail. The differences between these two missions, their different orbits and use of gyros give a particularly interesting feedback on the excellent behavior of this technology. One of the 4 PLANCK FOGs is oriented perpendicularly to the spin axis, making it possible to accurately characterize its measurement noise, and confirming that this remains unchanged with regard to ground acceptance test results. The COMS gyros are part of the spacecraft AOCS control loop, and thus are a major contributor to the excellent mission performances. During their use in the transfer phase, their high accuracy gave unprecedented visibility of micro-vibration and flexure in the various equipments and instruments, as well as the effects of spacecraft outgassing. Very positive lessons learnt from this in-orbit heritage are discussed. The paper concludes by briefly presenting the ASTRIX family latest development, the ASTRIX3M2, a promising three-axis, cost-competitive, high-performance IMU.