While NASA might be struggling to get its Starliner crew home, it's worth remembering that circa 12 years ago, the agency was celebrating the successful deployment of the Curiosity rover on the surface of Mars.

The six-wheeled trundlebot touched down on the Martian surface on August 5, 2012, showcasing just what the agency's boffins could do when given time, budget, and space to be creative. Resident vulture Iain Thomson was present at NASA's Jet Propulsion Laboratory (JPL) in Pasadena during the landing, which was chock full of more tension than the vast majority of movies set on the Red Planet.

Curiosity was the first NASA rover to use the agency's Sky Crane technology, quite different from the airbags of its predecessors, Spirit and Opportunity. The plan for the earlier rovers and last century's Mars Pathfinder mission was to use a parachute after atmospheric entry. Airbags would inflate around the lander during its descent. At around 20 meters (66 feet) from the surface, retro-rockets would fire to bring the descent to a halt, and then the lander would be dropped to bounce its way to a stop on the surface.

Curiosity was, however, a very different beast. For one, the rover is a lot larger than its predecessor. NASA also wanted to land it in places that airbags couldn't go. Engineers were forced to come up with an alternative: the Sky Crane. Yes, there was still a parachute. But that was where the similarities ended.

The Sky Crane approach had a lot to recommend it. Rather than needing a lander, the rover dangled from a "jet pack," meaning more rover payload and less mass being consumed by something to house the rover and provide a ramp. The rover itself was to be the lander, and its wheels would act as landing gear.

There was scope for more control over where the rover ended up. Also, where engines on the base of a lander might end up digging a hole that would be difficult to drive out of, putting them in a jetpack from which the rover hung meant Curiosity could land and go.

In its anniversary post, NASA wrote:

Despite the idea never being done on a NASA mission, engineers selected it and subjected themselves to the infamous "seven minutes of terror" on an August evening in 2012 as the rover hurtled toward Mars.

The landing was successful. The rover was on the surface. After a few short seconds, the cords connecting the rover to the rocket pack were severed, and the propulsion unit flew off to crash into the surface elsewhere.

Curiosity's exploration of the surface of Mars had begun. ®

Bootnote: Further reading

Curiosity's mission is ongoing, and NASA's website is full of history and updates about the rover. However, we also recommend Rob Manning's book Mars Rover Curiosity: An Inside Account from Curiosity's Chief Engineer for the low-down on the trials and tribulations of building the rover and its ground-breaking landing system, and the triumph of successfully landing the trundlebot on the Martian surface 12 years ago this month.

https://www.theregister.com//2024/08/12/in_celebration_of_curiositys_successful/