Free Astronomy Magazine November-December 2018

NOVEMBER-DECEMBER 2018 G raphic repre- sentation of the twin rovers 1A and 1B at work on the sur- face of Ryugu, together with Rover-2. The lat- ter will fall on the asteroid next year. [JAXA] In the video below, an over- view of the Haya- busa2 mission and, in particular, of the MASCOT operations. [DLR] and Rover-1B, developed by JAXA (Japan Aerospace Exploration Agency) and Univer- sity of Aizu, and housed in the Minerva-II1 container, have the shape of cookie boxes: two cylinders 18 cm wide, 7 cm high and 1.1 kg heavy. Each of them is equipped with a stereo camera, a wide-angle camera and a thermometer. Their service life could last the entire 15 months planned for the scien- tific mission in situ, since their energy au- tonomy is guaranteed by solar panels. Rover-2 is housed inside MINERVA-II-2 and was developed by a university consortium led by Tohoku University. It has the shape of an octagonal prism 15 cm wide and 16 cm high, and weighs about 1 kg. It is equipped with two cameras, LEDs to il- luminate dust in suspen- sion, an accelerometer, and a thermometer. Rover-2 is also powered by solar panels. Its land- ing on Ryugu is sched- uled for July, 2019. These three small rovers have in common the pe- culiarity of being able to move on the asteroidal surface not by wheels, but through leaps triggered by the acceler- ation and sudden braking of flywheels placed on more than one axis of their struc- ture. It is the first time that this solution has been put into practice in a space mission, and this is by far the best way to move a rover on rough and irregular terrains like those typical of the small bodies of the solar system. The fourth rover, the Mobile Asteroid Sur- face Scout (MASCOT) was developed by the Deutsches Zentrum für Luft- und Raum- fahrt (DLR) and the Centre National d’E- tudes Spatiales (CNES). It measures almost