Mobile Instrument Deployment Device (MIDD) (94-02)
The Mobile Instrument Deployment Device (MIDD) is a small wheeled-rover, designed as a simple solution to provide mobility to a payload of instruments on a planetary surface (wheel diameter: 160 mm; mass of platform: 2.3 kg. The maximum total mass is 7 kg, with a payload of 4.7 kg. Mars was the reference planet for this study. The wheel locomotion appeared as the only solution allowing implementing a reliable protection against dust storms - a rotary seal. Tests dedicated to this aspect have confirmed the validity of this choice. Each wheel is motorized independently. Lateral turns are performed by differential wheel rotation, with slippage. In addition, two wheels are each mounted at the end of a motorized lever, pivoting in the vertical plane. This allows:
a) an adaptation of the wheels to the terrain, and a better stability;
b) to increase the mobility with respect to slopes and obstacles;
c) to reduce the folded envelope of the device.
There are six actuators; each is a brush-less DC motor coupled to a planetary gearbox. DLR (D) with Contraves (CH) has performed the MIDD developments for ESA. During the last one, a prototype has been built and tested on a test bed at ambient. Further testing of the same prototype, to demonstrate its performance in thermal vacuum, is under consideration.
A MIDD could for instance carry a Mole as sampling device - as illustrated in C. A prototype of this concept has been built by DLR.
Last update: 22 February 2011