Here’s how Curiosity’s sky crane changed the way NASA explores Mars

Twelve years in the past, NASA landed its six-wheeled science lab utilizing a daring new expertise that lowers the rover utilizing a robotic jetpack.

NASA’s Curiosity rover mission is celebrating a dozen years on the purple planet, the place the six-wheeled scientist continues to make huge discoveries because it inches up the foothills of a Martian mountain. Simply touchdown efficiently on Mars is a feat, however the Curiosity mission went a number of steps additional on Aug. 5, 2012, touching down with a daring new method: the sky crane maneuver.

A swooping robotic jetpack delivered Curiosity to its touchdown space and lowered it to the floor with nylon ropes, then reduce the ropes and flew off to conduct a managed crash touchdown safely out of vary of the rover.

In fact, all of this was out of view for Curiosity’s engineering workforce, which sat in mission control at NASA’s Jet Propulsion Laboratory in Southern California, ready for seven agonizing minutes earlier than erupting in pleasure once they bought the sign that the rover landed efficiently.

The sky crane maneuver was born of necessity: Curiosity was too huge and heavy to land as its predecessors had—encased in airbags that bounced throughout the Martian floor. The method additionally added extra precision, resulting in a smaller touchdown ellipse.

Through the February 2021 touchdown of Perseverance, NASA’s latest Mars rover, the sky crane expertise was much more exact: The addition of one thing known as terrain relative navigation enabled the SUV-size rover to the touch down safely in an historic lake mattress riddled with rocks and craters.

Evolution of a Mars touchdown

JPL has been concerned in NASA’s Mars landings since 1976, when the lab labored with the company’s Langley Analysis Heart in Hampton, Virginia, on the 2 stationary Viking landers, which touched down utilizing costly, throttled descent engines.

For the 1997 touchdown of the Mars Pathfinder mission, JPL proposed one thing new: Because the lander dangled from a parachute, a cluster of big airbags would inflate round it. Then three retrorockets midway between the airbags and the parachute would carry the spacecraft to a halt above the floor, and the airbag-encased spacecraft would drop roughly 66 toes (20 meters) right down to Mars, bouncing quite a few occasions—typically as excessive as 50 toes (15 meters)—earlier than coming to relaxation.

It labored so properly that NASA used the identical method to land the Spirit and Alternative rovers in 2004. However that point, there have been only some areas on Mars the place engineers felt assured the spacecraft would not encounter a panorama characteristic that might puncture the airbags or ship the bundle rolling uncontrollably downhill.

“We barely discovered three locations on Mars that we may safely contemplate,” stated JPL’s Al Chen, who had essential roles on the entry, descent, and touchdown groups for each Curiosity and Perseverance.

It additionally grew to become clear that airbags merely weren’t possible for a rover as huge and heavy as Curiosity. If NASA wished to land greater spacecraft in additional scientifically thrilling areas, higher expertise was wanted.

Rover on a rope

In early 2000, engineers started taking part in with the idea of a “sensible” touchdown system. New sorts of radars had turn into accessible to supply real-time velocity readings—info that might assist spacecraft management their descent. A brand new kind of engine could possibly be used to nudge the spacecraft towards particular areas and even present some elevate, directing it away from a hazard. The sky crane maneuver was taking form.

JPL Fellow Rob Manning labored on the preliminary idea in February 2000, and he remembers the reception it bought when folks noticed that it put the jetpack above the rover somewhat than under it.

“Individuals have been confused by that,” he stated. “They assumed propulsion would at all times be under you, such as you see in previous science fiction with a rocket touching down on a planet.”

Manning and colleagues wished to place as a lot distance as potential between the bottom and people thrusters. Apart from stirring up particles, a lander’s thrusters may dig a gap {that a} rover would not have the ability to drive out of. And whereas previous missions had used a lander that housed the rovers and prolonged a ramp for them to roll down, placing thrusters above the rover meant its wheels may contact down instantly on the floor, successfully performing as touchdown gear and saving the additional weight of bringing alongside a landing platform.

However engineers have been not sure tips on how to droop a big rover from ropes with out it swinging uncontrollably. how the issue had been solved for large cargo helicopters on Earth (known as sky cranes), they realized Curiosity’s jetpack wanted to have the ability to sense the swinging and management it.

“All of that new expertise offers you a combating probability to get to the suitable place on the floor,” stated Chen.

Better of all, the idea could possibly be repurposed for bigger spacecraft—not solely on Mars, however elsewhere within the solar system. “Sooner or later, in case you wished a payload supply service, you may simply use that structure to decrease to the floor of the moon or elsewhere with out ever touching the bottom,” stated Manning.