IL NUOVO CIMENTO Vol. 112 A, N. 1-2 Gennaio-Febbraio 1999 Experiments for light flash observation in space( ∗ )( ∗∗ ) A. Morselli( ∗∗∗ ) Dipartimento di Fisica, Universit` a di Roma ”Tor Vergata” and INFN Roma 2 Via della Ricerca Scientifica 1, 00133 Roma, Italy (ricevuto il 4 Settembre 1998) Summary. — Semiconductor detectors can be of great help for the study of radiation-induced effects on living objects and men in space. Here we present three projects: the Sileye 1 and 2 and ELFO. The Sileye detector series are the first parti- cle detectors flown in space made by the Italian Institute of Nuclear Physics (INFN). The detectors consist of six silicon views made of a square (6 × 6 cm 2 ) wafer of sili- con, divided into 16 strips, each 3.6 mm wide. The first detector is on board MIR since October 1995; the second apparatus, Sileye2, was brought on MIR on October 1997 and it will be turned on in February 1998. Here we will present briefly the results obtained with Sileye1 and the performances of the second apparatus. The ELFO project is a much more ambitious one and it is planned for the International Alpha Station. Here we will review scheme and purpose PACS 29.40 – Radiation detectors. PACS 61.82 – Radiation effects on specific materials. PACS 01.30.Cc – Conference proceedings. 1. – Introduction The most important macro effect of the radiation in space on the men is the phe- nomenon of light flashes (LF) in cosmonauts’ eyes during orbital flights. The first ob- servation was reported by Aldrin during the Apollo 11 mission [1]. Other observations were later reported by Apollo-Soyuz [2] and cosmonauts on the MIR Space Station; the frequency of LF depends on orbit parameters, especially on the latitude and grows in polar areas and in the area of the South Atlantic Anomaly, but although many study and experiments in space and on earth were performed (for a review see [3] and references ( ∗ ) Paper presented at the “3rd International Conference on Large Scale Applications and Radiation Hardness of Silicon Detectors”, Firenze, October 1-3, 1997. ( ∗∗ ) The author of this paper has agreed to not receive the proofs for correction. ( ∗∗∗ ) E-mail: morselli@roma2.infn.it c  Societ` a Italiana di Fisica 95