Curiosity’s tyres ‘tagging’ Mars

Yesterday the Mars Curiosity rover successfully went into action on the surface of the red planet, and the vehicle’s tyre tracks have gained a measure of notoriety. It turns out that Curiosity is ‘tagging’ the surface of Mars as it drives about.

A series of notches included in the track tyre tread is not just a pretty pattern – the notches are in fact Morse Code and spell out the letters ‘JPL’, short for NASA’s Jet Propulsion Laboratory. Curiosity is now busy leaving the laboratory’s initials all over Mars, however this tagging is not just wanton interplanetary vandalism – the dots and dashes are part of the rover’s visual odometry system, used to estimate changes in position over time.

Unlike the Goodyear-developed Moon rover tyres four decades ago, the tyres used on Curiosity are not the product of any tyre manufacturer – the tyres were built at the Jet Propulsion Laboratory’s own Mars Science Laboratory. The tyres are 100 per cent aluminium and feature a zigzag tread intended to help the rover climb out of craters. Each of the six tyres fitted to Curiosity weigh some 15 to 20lbs or 7 to 10 kilogrammes. The wheels’ interior spokes and centre hubs are made of titanium, which offers both strength and flexibility.

Those worried about the impact the Curiosity’s tyres may have on any obstacles the vehicle meets will be pleased to learn that there are no cats on Mars.