Isothermal FFDP-Test and SCF-Test of Flight-quality Uncoated Cube Corner Laser Retroreflectors S. Dell’Agnello 1 , G. O. Delle Monache 1 , D.G. Currie 2 , R. Vittori 3 , C. Cantone 1 , M. Garattini 1 , A. Boni 4 , M. Martini 1 , C. Lops 1 , N. Intaglietta 1 , G.Bianco 5 , M. Maiello 1 , S. Berardi 1 , L. Porcelli 1 , G. Patrizi 1 1 Laboratori Nazionali di Frascati (LNF) dell’INFN, Frascati (Rome), Italy, 2 University of Maryland (UMD), College Park, MD, USA and NASA Lunar Science Institute, NASA Ames Research Center, Moffett Field, CA, USA, 3 Aeronautica Militare Italiana (AMI) and Agenzia Spaziale Italiana (ASI), Rome, Italy, 4 University of Rome “Tor Vergata” and INFN-LNF, Rome, Italy, 5 ASI, Centro di Geodesia Spaziale “G. Colombo” (ASI-CGS), ABSTRACT Using dedicated facilities of INFN-LNF in Frascati, Italy, including the “Satellite/lunar laser ranging Characterization Facility” (SCF,[1]), we characterized the detailed thermal behaviour and/or the optical performance of many flight units of coated and uncoated cube corner laser retroreflectors (CCRs). As a reference for the ILRS community, with this article we provide a compilation of the many tests carried out in the last years on uncoated CCRs (tests on coated CCRs are reported in detail in [1]). 1. Industrial optical acceptance test of 110 LARES Flight CCRs (ASI reference document: DC-OSU-2009-012) The work reported in this section has performed by INFN-LNF authors only. At the end of 2008 INFN-LNF was requested by ASI 1 to perform an industrial acceptance test of all of the 110 CCRs of the LARES satellite. LARES is a tungsten sphere passive satellite of about 18 cm radius, covered with 92 CCRs made of fused silica. It will orbit at a nearly circular orbit with semi-major axis of about 7900 Km. The CCRs used for the satellite were manufactured by ZEISS, but in order to asses the compliance with their specification ASI requested INFN-LNF to do FFDP (Far Field Diffraction Pattern) measurements of those CCRs. Specifications of LARES CCRs were:front face aperture of 1.5”, DAOs 2 = 1.5±0.5 arcsec. We performed FFDP measurements at the SCF, in air at room temperature, in 3 working weeks before Christmas 2008, on a red laser optical table (He-Ne, λ=632.8 nm) [2], since CCRs were designed by ZEISS at this wavelength. In Fig. 1 we can see one of the measured CCRs. In order to define a criterium of acceptance for the CCRs, we referred to the shape of the FFDP of an uncoated CCR with front face aperture of 1.5” and DAOs as specified before, oriented with a physical edge vertical and an horizontally polarized beam. Figure 1 (left) Measured FFDP of one of LARES CCRs. (right) Average intensity vs velocity aberration, comparison measurements simulations. Measured intensity has ±25% relative intensity error not shown 1 1 Italian Space Agency 2 Dihedral Angle Offset