We discuss a general scheme of the optics and electronics read out as well as preliminary test results of a detector prototype for the space fluorescence telescope TUS (FD-TUS). The mirror of this prototype is coupled to an 8 by 8 pixel camera. Each of the 64 pixels is read by one PMT of 13 mm diameter (Hamamatsu model R1463) . The optics design is a multi-hexagonal segmented telescope with focal distance of 1.5m and 2 square meter area. The optics design is optimized to have a light collection efficiency greater then 50% for all the pixel positions. The fluorescence detector is being tested at the high mountain site Sierra La Negra near Puebla City in Mexico (600g/cm2). The FD-TUS will observe EAS tracks at energies of about 1 EeV at distances 25-50km,and zenith angles greater than 45 degree with direction tracks perpendicular to the FD axis.

Proceedings of the 30th International Cosmic Ray Conference; Rogelio Caballero, Juan Carlos D'Olivo, Gustavo Medina-Tanco, Lukas Nellen, Federico A. Sánchez, José F. Valdés-Galicia (eds.); Universidad Nacional Autónoma de México, Mexico City, Mexico, 2008; Vol. 5 (HE part 2), pages 1183-1186