The moment of truth has arrived for the US space agency’s Perseverance rover.
The six-wheeled robot is fast approaching Mars after a seven-month, 470-million-km journey from Earth for what unquestionably will be the most challenging part of its mission.
It’s got to put itself down safely on the Red Planet – a task that has befuddled so many spacecraft before it.
But if Perseverance is successful, it has an amazing opportunity to find signs of past life on Mars.
Never has a science mission gone to the planet with so sophisticated a suite of instruments; never has a robot been targeted at so promising a location.
Jezero Crater, the intended touchdown zone, bears all the hallmarks in satellite imagery of once having held a giant lake. And where there’s been abundant water, perhaps there’s been biology as well.
Key timings for Perseverance’s landing
- Contact with atmosphere: 20:48 GMT
- Parachute deployed: 20:52 GMT
- Powered descent: 20:54 GMT
- Wheels down: 20:55 GMT
Perseverance will sift and drill into the sediments to look for traces of ancient microbial activity. The most propitious examples will be packaged for return to Earth by later missions.
“But before we can get that surface mission going, we have to land on Mars and that is always a challenging feat,” said Matt Wallace, Nasa’s deputy project manager for Perseverance.
“This is one of the most difficult manoeuvres we do in the space business. Almost 50% of the spacecraft sent to the surface of Mars have failed, so we know we have our work cut out to get down safely at Jezero.”
Perseverance is on a path to engage the Martian atmosphere late on Thursday (GMT).
It will plunge into the rarefied air at more than 20,000km/h and it will have to reduce this to near-walking pace by the time it reaches the surface – a daunting prospect that Nasa engineers half-jokingly call the “seven minutes of terror”.
The robot’s protective capsule will do most of the work of scrubbing off the entry speed but a supersonic parachute and a rocket jetpack, or “Sky crane”, will be needed for the last three minutes of braking and surface placement.
Much is made of the difficulty of mounting Mars missions, and it’s true many have failed. But the statistics actually favour Perseverance.