Tecnological research


ContactS. Dell’Agnello

Typology: Instrumental

Moon laser tracking to perform precision tests of general relativity

The SCF_Lab group works on the analysis of Lunar Laser Ranging (LLR) data acquired since 1969 from the laser retroreflector arrays deployed by the Apollo and Lunokhod missions on the lunar surface. We analyze these LLR data with the highly specialized “Planetary ephemeris Program” (PEP) initially developed by I. Shapiro at the Harvard-Smithsonian Center for Astrophysics (CfA) and now maintained by J. Chandler of CfA. With our analysis, we reach precision tests of general relativity: the strong and the weak equivalent principle (SEP, WEP), the time variation of the gravitational constant (Gdot/G), the PPN parameter beta, the geodetic precession and the inverse-square force law. These are among the best tests of general relativity. The group also works on the design, construction and space qualification of next-generation lunar laser retroreflectors (MoonLIGHT and INRRI) in collaboration with the University of Maryland. In Italy, we collaborate with the ASI Matera Laser Ranging Observatory (MLRO) and the University/INFN Padova. MoonLIGHT and INRRI will improve over the performance of the Apollo/Lunokhod retroreflectors by up to a factor 100, thus opening a new era of test of general relativity and new gravitational theories. Finally, we have opportunities to deploy MoonLIGHT and INRRI on the Moon with the next, imminent lunar landing missions.