The second of June 2003 a European space probe ,called Mars Express was launched to Mars. This has been the first
European mission to the red Planet and for the first time in only about three years a complex spacecraft was designed
built and launched. Among the eight experiments MARSIS is one of the most important if not the most important. It
is a radar sounder designed primarily to find subsurface discontinuities that may be due to water in liquid, solid or
permafrost forms. In order to penetrate the planet surface a relatively low frequency need to be used, consequently a
very long dipole antenna is required. This arose a design challenge that in the end lead to a not proper solution for the
antenna deployment. As a consequence the deployment of MARSIS antenna has been postponed until the end of
June 2005. First data are being collected and analyzed. The main issues that caused the delay in the MARSIS antenna
deployment will be reviewed. Also a description of Mars environmental models and MARSIS system description
will be reported
