ESA Science News

Mars Express on target and forging links with Japan Progress on building the Mars Express spacecraft is proceeding according to plan. "We are following our schedule," Rudi Schmidt, Mars Express project manager, said last week at a science working team meeting attended mainly by scientists who are building payload instruments.
Project teams at Matra Marconi Space (MMS) Toulouse, the prime contractor, and at ESA’s technical centre, ESTEC, are now at full strength and all sub- contractors have been appointed, said Schmidt. Issues raised at the preliminary design review (PDR) at the end of last year (see earlier news story) have largely been resolved; and potential problems with on-board software have been avoided by reducing the inherent flexibility required of some of the spacecraft’s housekeeping.
All payload instrument teams reported that they are now moving from the design phase, phase B, into the construction phase, phase C/D. They are on target for delivering EM models of their instruments to MMS after the summer, followed shortly by structural models (SM). The EM models will be used to test the electrical interfaces of each instrument with the spacecraft and the SM models to test physical interfaces.
The meeting heard that a potential problem with vibration during launch disappeared with the first two test flights of the Soyuz-Fregat launcher. "We had been concerned that vibration during launch would threaten the survival of some of the instruments," said Schmidt. "But the first two test flights went extremely well." Vibration levels were well below those originally given as an upper estimate by Starsem, the Russian-French launcher company.
Representatives from MMS went over the instrument testing procedures for the benefit of the instrument teams and a representative from ESOC, ESA’s space operations centre in Darmstadt, Germany, summarised their progress and the capabilities of a software tool that will shortly be available to simulate the orbits of Mars Express around Mars. The tool will help instrument scientists to plan when to turn their instruments on and off during each orbit.
The teams are preparing to forge closer links with their counterparts in Japan, who are flying instruments on the Nozomi spacecraft which will arrive at Mars shortly after Mars Express. Hajime Hayakawa from ISAS, the Japanese space agency, told the meeting that Nozomi will follow an equatorial orbit which will be complementary to Mars Express’s polar orbit. Nozomi’s chief interest will be the upper atmosphere: its 14 instruments will record electron density and temperature profiles. Hayakawa proposed that a joint working team be set up and hold its first meeting in Japan in the autumn.
Mars Express in orbit.