Curiosity survives the seven minutes of terror
A rocket-powered crane lowered an 899-kilogram rover onto the floor of Gale Crater on cables. The system had never been flown, and it worked first time.
Curiosity touched down at 05:17:57 UTC on 6 August 2012; JPL heard thirteen minutes and forty-eight seconds later, the one-way light time to Mars.
The problem was mass: at 899 kilograms, roughly five times Spirit or Opportunity, Curiosity was too heavy for airbags. The capsule hit the atmosphere at about 5.8 kilometres per second behind a 4.5-metre heat shield, the largest ever flown to another planet, and flew a steered, lifting entry, shedding tungsten ballast to shift its centre of mass. A supersonic parachute nearly 16 metres across opened about twelve kilometres up, at about 405 metres per second; the heat shield fell away, then back shell and parachute. A descent stage with eight throttleable engines flew clear of the debris, slowed to walking pace about twenty metres up, and winched the rover out beneath itself on nylon cables. When the wheels took the load, pyrotechnic blades cut the cables and the descent stage flew off to crash clear.
The sky crane had never been flown and could not be tested end to end on Earth, where air and gravity are both wrong. It ran through seventy-six pyrotechnic devices in about seventeen minutes, with no way to intervene; JPL's animation called it the seven minutes of terror. Two weeks earlier a six-second thruster burn had nudged the 2001 Mars Odyssey orbiter six minutes ahead in its orbit, to be overhead relaying landing telemetry live.
Curiosity stopped 2.4 kilometres from its target centre, on Aeolis Palus at 4.6 degrees south. Gale Crater, 154 kilometres across, was chosen for the mountain at its centre: Aeolis Mons, informally Mount Sharp, about five kilometres of layered sediment recording martian climate. The brief was not to find life but to establish whether the place could ever have supported it — narrower than the question Viking asked and failed to close.
Curiosity is still driving; in August 2026 it passed a kilometre of vertical climb. Perseverance reused the architecture in February 2021, adding terrain-relative navigation.