The weight of Curiosity

Nasa officials are calling the landing crazy, but when the new Mars rover Curiosity hurtles towards the planet's surface tomorrow, crazy could bring a big payoff.

What could go wrong? When the new Mars rover Curiosity hurtles towards the planet's surface tomorrow morning UAE time, it will be travelling at speeds in excess of 21,000kph. The rover will separate from its capsule, deploy a heat shield and coast towards the firmament. At 11 kilometres from the ground, it will deploy a giant parachute; at eight kilometres, radar will scan for a choice landing zone; at 1.5 kilometres, it jettisons the parachute and a retro-rocket backpack takes over. Twelve seconds before landing, the booster is ditched, which then flies out of harm's way. Bungle any single step, and Curiosity is no more.

Even Nasa officials are calling the landing crazy, but it's worth the risk. There have been other missions to the Red Planet, from Viking1 and Viking 2 launched in 1975, to the 1997 Mars Pathfinder and the 2003 landings of Spirit and Opportunity, the latter of which still gamely toils through the Martian sand.

Curiosity's scope, however, dwarfs these missions. It's size - compared to a compact car - necessitates the tricky landing, but also gives it sophisticated analytical tools to search for signs of microbial life. These could be exciting days indeed, and that breakneck descent is just the beginning.