Free Astronomy Magazine November-December 2015

ASTRONAUTICS 28 NOVEMBER-DECEMBER 2015 Hedgehogs, enclosed in a special environ- ment, performed sev- eral types of manoeu- vres on surfaces of dif- ferent composition and consistency, which in first approximation mimic those present on smaller bodies; namely, icy, rough and rocky, sandy, or crum- bly and soft surfaces. Among the most dar- ing manoeuvres per- formed by the robots there is also the one called “tornado”, which consists in a fierce vertical spinning, useful in case the Hedgehog falls into a cra- ter, sinkhole or other situations, from which, within certain limits, it will be able to launch itself out with a single leap. The set of tests performed by the robots aboard Zero-G have shown that they are capable of operating on asteroids and comets, with the advantage over traditional rovers of having access to many more surface structures, un- reachable with explorations on wheels. In addition to their greater employability with respect to ro- vers, with the same onboard scientific in- strumentation they are also much less ex- pensive to produce and, thanks to their shape and small size, it will be easy to tran- sport quite a few of them in a single mis- sion. It will thus be possible to place sev- eral Hedgehogs in dif- ferent regions far from each other, essential for gaining an overall knowledge of the vis- ited object. Each robot will communicate with Earth by radio link via an orbiting probe, in the same way as done by Mars ro- vers. The researchers involved in the de- velopment of the Hedgehogs are currently working on enhancing their artificial intelli- T his video shows a series of manoeuvres performed under microgravity conditions by a Hedge- hog prototype during parabolic flights aboard the Zero-G NASA air- craft. [NASA/JPL-Caltech/Stanford Univ., MIT] H ere we have instead a simula- tion of how a Hedgehog could move on the surface of the asteroid Itokawa, explored in 2005 by the Jap- anese probe Hayabusa. The Hedge- hog speed has been accelerated by 100 times. [Stanford Autonomous Systems Laboratory] I n the back- ground, the ideal match of a Hedgehog with the Martian sur- face, to underline that this type of robot can be use- fully employed also in the explo- ration of large planetary bodies. [NASA/JPL-Cal- tech/Stanford]