Print
Email
0
0
In unusually graphic language, Nasa has described the period leading up to next month’s landing of its car-sized Curiosity rover on Mars as “seven minutes of terror”. In that time, the craft must reduce its speed from 6.1 km per second to make a gentle pin-point landing in Gale crater. To put it as close as possible to the most interesting geology, its target is now a 7km by 20km ellipse at the foot of Mount Sharp which climbs higher than Mont Blanc at the crater’s centre.
The bulk of Curiosity’s speed is shed using a heat shield, but the craft is still moving at 405 metres per second when it deploys a parachute at a height of 11km. The heat shield then falls away to reveal a descent stage with retrorockets which take over from the parachute at a height of 1.4km and slow the drop to walking pace. Nylon cords then unwind to lower the rover the final 20 metres to the surface. After the cords are severed, the descent stage should veer off to the side to crash out of harm’s way
The landing is due at 06:31 BST on 6 August and the challenging sequence of events leading up (or down?) to it must occur entirely automatically. Indeed Mars lies 248 million km or 13.8 light minutes from Earth at the time so those fateful seven minutes will be history for Curiosity before we see them commence. To complicate matters further, a rash of recent problems with Nasa’s Odyssey orbiter may mean it is out of position to relay immediate news of the final stages of the descent and touchdown.
Average Rating