In a couple of weeks we’lll see yet another step in mankind’s quest to conquer space – a rover mission to Mars, called Curiosity. I’ve followed these Mars missions with interest since having a go at designing a Mars rover back in university. Actually, when I say ‘design’, it was more a list of engineering problems which would need to be solved to make the thing work at all. Chief amongst these problems is the computing power to keep the craft safe as it rolls around, given that the 8 minute round trip for radio signals to Mars would be too long to allow remote control from Earth. Now, some 3 decades since university, we have all the computing power we need.
Whilst we’ve had several rovers already, this one is different in two key ways. Firstly, it’s much bigger than previous rovers, about the size and weight of a family car. This means it will be able to do all sorts of great science that previous rovers couldn’t. This also means however that landing the thing is problematic. Previous rovers have used different techniques such as parachutes and bouncing down in a clutch of balloons.
That’s where the second difference comes in. This craft has a much more elaborate landing sequence which is not only designed to lower this large mass to the ground safely, but also provides much greater accuracy in landing spots.
This video nicely shows the sequence involved in the landing – if it works, it’s a triumph of a number of fields of engineering – computing, aeronautics, propulsion and so on. The whole landing sequence will take about 7 minutes, and NASA’s project people have dubbed this period ‘7 minutes of terror’, as they wait to see if it all worked.