SMART-1 mock-up assembled
29 Jun 200027 months away from launch, the SMART-1 project team and its industrial partners now have their very first full-scale version of Europe's lunar satellite. The main assembly of the mock-up was completed at the facilities of the prime contractor Swedish Space Corporation (SSC) in Solna (near Stockholm) on 12 June.
The mock-up is the first of several models that will be produced during the course of the SMART-1 programme. It will be used between now and this autumn to produce the electrical harnesses, the myriad of cables linking all the spacecraft systems and the mission's science and technology experiments.
The views give the very first impression of what the SMART-1 spacecraft body will look like. Although several extra elements have been added since these pictures were taken, the mock-up is a surprisingly impressive structure with its large bright aluminium surfaces.
The mock-up clearly shows several of the main elements of the spacecraft: the central conical cavity for the propellant tanks, the wider section at its base which will house the electric propulsion thruster, the internal support structures for the various experiments and spacecraft subsystems, dummies of the two pairs of reaction wheels, and visible on two opposite sides, the two cylindrical interfaces for the arms of the solar array. One also notes the hinged panel for easy access.
"My very first reaction - says ESA Project manager Giuseppe Racca - is that our spacecraft, roughly one cubic meter in volume, is in fact not all that small. There appears to be a fair amount of free space left inside. But the driving factor of our mechanical design has been the size of the interface with the Ariane 5 launcher. Looking at the spacecraft's bottom panel one notes that there are in fact only a few centimetres left between the conical interface and the sides."
The spacecraft harness is being produced by SAAB. Once all its cables are fitted, connecting most of the spacecraft electrical subsystems and dummy versions of the science instruments, they will be used on an identical mock-up, but this time connecting functional units for the first electrical test which will start in August.
A third mock-up, equipped with antennas and solar panels, will be submitted to radio-frequency tests. Another identical harness will also be integrated in November into a structurally representative model of the spacecraft which is already being manufactured.
"The launch in October 2002 may seem some time off - says Racca - but our schedule is tight. We are at an early stage of the spacecraft development, all the other phases have to fall in line at the required moment. But passing from the drawing boards to real spacecraft hardware and seeing this mock-up is certainly very motivating for all of us."