NASA's Opportunity rover that went into hibernation after a dust storm swept over the region and blocked sunlight from reaching it, has completed 15 years on the Red Planet.
The rover landed in a region called Meridiani Planum on January 25, 2004, sending its first signal back to Earth from the surface at 12.05 a.m., the US space agency said in a statement on Thursday.
The golf-cart-sized rover was designed to travel 1,006 metres and operate on the Red Planet for 90 Martian days (sols). It has travelled over 45 km and logged its 5,000th Martian day last February.
"Fifteen years on the surface of Mars is a testament not only to a magnificent machine of exploration but the dedicated and talented team behind it that has allowed us to expand our discovery space of the Red Planet," said John Callas, project manager for Opportunity at NASA's Jet Propulsion Laboratory in California.
"However, this anniversary cannot help but be a little bittersweet as at present we don't know the rover's status. We are doing everything in our power to communicate with Opportunity, but as time goes on, the probability of a successful contact with the rover continues to diminish," Callas added.
Opportunity's last communication with Earth was received June 10, 2018, as a planet-wide dust storm blanketed the solar-powered rover's location on the western rim of Perseverance Valley, eventually blocking out so much sunlight that the rover could no longer charge its batteries.
Although the storm eventually abated and the skies over Perseverance cleared, the rover has not communicated with Earth since then.
However, Opportunity's mission continues, in a phase where mission engineers at JPL are sending commands to as well as listening for signals from the rover. If engineers hear from the rover, they could attempt a recovery.
Opportunity and its twin rover, Spirit, launched from Cape Canaveral, Florida, in 2003. Spirit landed on Mars in 2004, and its mission ended in 2011.