Mars Express completes its first journey - from Zurich to Stevenage
13 March 2001If youre travelling on Europe's roads this year, you may spot a very large vehicle (5m long and 3.5m wide), bearing the Mars Express logo. It will be making slow progress and will be accompanied by a police escort. Inside the clean, air-conditioned environment will be the Mars Express spacecraft in transit between industrial contractors in Switzerland, the UK, Italy or France.
Organising such transport is no mean task, as each European country has different regulations concerning the movement of oversize vehicles. Some, for example, forbid movement at weekends, some allow it during daylight only and one, Germany, during night-time only. Police escorts have to be changed at national borders.
Despite these logistical difficulties, the trailer completed its first journey last week when it successfully delivered the spacecraft structure to Astrium, Stevenage, UK after a two-day journey from Contraves, Zurich, Switzerland. On each successive journey, Mars Express will be nearer its final flight configuration as parts are added or tested at the various locations.
Alistair Scott, a spokesman for Astrium, UK, was in Stevenage last week to meet the trailer. "We lifted the box containing the spacecraft off the lorry and then started to prepare it for entry to our clean room. We moved it in later that day and unboxed it the following morning. It's really exciting to be working on Europe's first mission to Mars," he says.
Mars Express will remain in Astrium's clean room whilst the propulsion system is fitted and tested. Then, sometime in July, it will be loaded onto the trailer again for transport to Alenia, Turin, Italy where dummies of all the other units will be added. A month later, it will travel to Intespace, Toulouse, France for mechanical testing. Then in October, it will be back to Alenia, Turin again where the dummies will be dismounted in preparation for integration of the final flight units.
In the meantime, development and testing of the flight units is proceeding according to plan at Astrium's electrical test bench in Toulouse, France. The test bench went into operation last summer (see Mars Express comes alive) to ensure that all the sub-systems and scientific instruments are electrically compatible. First, the on-board computer was tested, then the remote terminal units and other systems and finally the scientific instruments. Only three of the scientific instruments remain to be tested.
The electrical and structural model tests should also be completed in October 2001. The next stage will be to integrate flight models of all instruments and sub-systems with the spacecraft and then test the complete system during 2002.