The American space agency says its Perseverance rover is lined up perfectly for its landing on Mars.
The robot is heading for a touchdown on Thursday in a crater called Jezero just north of the planet’s equator.
Its mission objectives will be to search for signs of past life and to collect and prepare rock samples for return to Earth in the 2030s.
Engineers told reporters that as things stand they don’t plan to make any more changes to the robot’s trajectory.
All the navigation data indicates it is right on track to intersect Mars at the intended moment in time and space.
“We still have the ability to do another manoeuvre if we need to, but we don’t expect we’ll have to,” Jennifer Trosper, Nasa’s deputy project manager for Perseverance, told BBC News.
Tuesday saw Perseverance duck under half-a-million km left to travel.
A signal from the rover to say its protective capsule has engaged Mars’ atmosphere should arrive on Earth at about 20:48 GMT on Thursday. If all goes well, confirmation that the robot is safely on the ground will come roughly seven minutes later.
Mission control at the agency’s Jet Propulsion Laboratory in California will be following events in arrears.
The current 190m-km separation between the planets means all communications take over 11 minutes to arrive, making it impossible for engineers to intervene if something does go wrong. Autonomous systems on Perseverance are in charge.
To the casual eye, the robot looks exactly the same as the Curiosity rover that Nasa put down in Gale Crater in 2012. But “under the bonnet”, the new vehicle is quite different, with an enhanced suite of instruments that will enable it to address a new set of scientific questions.
The hope is it’s also more robust than Curiosity, said chief engineer Adam Steltzner
“Curiosity’s wheels took quite a beating on the surface of Mars because of the these sharp rocks called ventifacts,” he explained. “Perseverance has a gentle tread pattern. That tread pattern not only makes her wheels stronger against rocks, it also gives them better performance in sandy terrain.”
