NASA’s Perseverance rover is gearing up for its mission to Mars in just two months’ time. The latest step in the launch preparations is readying the rover and its descent stage to be attached to the Atlas V rocket that will transport it in a process called vehicle stacking.
The rover’s descent stage, along with some other components including the recently-name Ingenuity helicopter, is carefully lifted and placed on top of the rover itself, then attached with three flight-separation bolts. The combined package is then placed inside a black shell along with its parachute, ready to be set onto the rocket.
“Attaching the rover to the descent stage is a major milestone for the team because these are the first spacecraft components to come together for launch, and they will be the last to separate when we reach Mars,” David Gruel, the Perseverance rover assembly, test, and launch operations manager at NASA’s Jet Propulsion Laboratory said in a statement. “These two assemblies will remain firmly nestled together until they are about 65 feet [20 meters] over the surface of Mars.”
Once the spacecraft arrives at Mars, the three bolts holding the descent stage and the rover together will be released using pyrotechnic charges, allowing a part of the decent procedure called the “sky crane maneuver” to begin.
Because the Perseverance rover is larger and heavier than previous Mars rovers, it cannot use an airbag landing system like those before the Curiosity rover. Instead, the sky crane system has nylon ropes hanging from the descent stage which hold the rover in place 25 feet (7.6 meters) below. When the rover touches down on the surface, it senses the contact and uses blades to cut the ropes, allowing the descent stage to lift off and move away. The advantage of this system is that Perseverance will land neatly on the surface with no parts of airbags or other components in its way.
The launch of the rover is scheduled for summer this year, will a launch window opening on July 17. If everything goes as planned, the rover should land on Mars in the Jezero Crater on February 18 2021, where it can begin its mission of searching for signs of ancient life.
