GRLOW · GRAVITATIONAL WAVE DETECTORS LOW-FREQUENCY TECHNOLOGY TEST BED

Gravitational waves are a prediction of Albert Einstein's Theory of General Relativity, which have not been directly detected to date. Current on-ground gravitational wave detectors, like LIGO, VIRGO and GEO600, are limited at low frequencies due to seismic noise and human activity. These instruments are currently being upgraded, at the same time that the European Space Agency is currently in the final integration phase of the first mission to test gravitational wave detection technologies in space, LISA Pathfinder, with expected launch in 2014.In this framework, we propose a facility to test technologies and materials for gravitational wave detection in space. The proposed set-up is composed by a very high-precision (10^(-6) K/sqrt(Hz)) thermally controlled vacuum tank which allows to suppress environment fluctuations in the low frequency regime, i.e. down to 0.1 mHz. Inside the tank, an interferometer with picometer sensitivity will allow the characterization of materials used in space applications (like Carbon-Fiber Reinforced Plastics or Silicon Carbide) and opto-electronics equipment (like photodiodes or optical fibres) in a high stability environment. The proposed facility will be able not only to screen the environmental fluctuations but to generate controlled perturbations to characterize the samples in a measuring bandwidth relevant for space applications.The technologies to be tested in this low-frequency test bed are of wide application in space technology. In particular, spacecraft-to-spacecraft interferometry concepts are currently being considered for geodesy missions, as in the case of the GRACE (Gravity Recovery and Climate Experiment) follow-on missions, which share similar low-frequency and high-precision requirements as the gravitational wave detection missions. The proposed test bed can thus be considered a transversal test facility for space-related technologies.