Three years ago today NASA’s Mars Exploration Rover Spirit plunged through the red planet’s atmosphere and bounced to a stop on its rocky surface while hushed engineers and scientists waited for news here on Earth.

Spirit touched down inside Mars’ Gusev Crater on Jan. 3 at 11:35 p.m. EST (it was 8:35 p.m. at the rover’s Jet Propulsion Laboratory control center in Pasadena, California) [image 1, image 2, image 3]. The rover survived an early software glitch and a wonky front wheel as it roamed across the martian surface.

And now, several mission extensions later, Spirit and its robotic sister Opportunity continue to soldier on long after surpassing their minimum 90-martian day mission. Spirit has spent 1,068 martian days—or sols—exploring Mars, snapped and delivered some 88,500 photos, scaled one red planet hill, and rolled across 4.3 miles (6.9 kilometers) of rocky terrain. The rover is currently exploring the Home Plate region of Gusev [image 1, image 2].

Not to mention that, together with Opportunity and the help of several Mars orbiters, Spirit has helped peel back the hidden history of water on the red planet.

Spirit and Opportunity have lasted so long, NASA engineers have been able to upload new software that will allow the rovers to recognize certain martian features and keep visual tabs on terrain during drives. The software also gives the rovers freedom to decide when it is safe to reach out with their instrument laden arms to touch rocks or other interesting targets.

“Before this, the rovers could only think one step ahead about getting around an obstacle,” said John Callas, JPL’s project manager for the rover mission, in a statement. “With this new capability, the rover will be smarter about navigating in complex terrain, thinking several steps ahead. It could back out of a dead-end cul-de-sac. It could even find its way through a maze.”

To date, NASA has set aside about $922 million on Spirit and Opportunity missions, which includes their initial $820 million price tag plus the additional mission extensions, the space agency said.