In this project the Hanbury-Brown and Twiss experiment is tested with the purpose of performing it in space. Compared to amplitude interferometry requiring 30 nanometre precision, the mechanical requirements here are not exacting, on the 3mm scale. A number of separate light collectors register single photons arriving from the same celestial object. The correlation of these photon streams, at a central station, allows measurement of the size of distant stars and galaxies.
