Although the likelihood of recovering stricken Mars Exploration Rover Spirit was slim, a tiny sliver of hope endured that the tenacious rover would eventually send a signal back to Earth.
Sadly, today, NASA confirmed news that was as inevitable as it was unwelcome: the final command will be sent to the Red Planet on Wednesday, and orbiting Mars satellites will cease search operations at the end of the month.
That means it's official (or it will be in a few days): Spirit is dead.
After getting stuck in a sand trap nicknamed "Troy" in Gusev crater in Apr. 2009, NASA admitted defeat at trying to free the six-year old Spirit in Jan. 2010 - Spirit (and sister rover Opportunity) only had a mission profile lasting three months.
Then, by March 2010, as the rover became a stationary observation post, Spirit's woes worsened.
The winter sunlight was dwindling, and NASA's rover drivers were unable to optimize the rover's position to receive as much sunlight as possible across its solar panels, Spirit's batteries began to drain, forcing her into a hibernation state.
"Spirit went into a deep sleep," said project manager John Callas of NASA's Jet Propulsion Laboratory.
Ever since, Spirit has remained silent, despite many attempts at signaling the rover and scanning for any faint "beep" on the Martian surface.
Although Spirit's cause of death will likely remain unknown - until a manned excursion to Mars, whenever that may be - it is highly probable that the rover's internal electronics became damaged in the frigid temperatures she sustained during the Martian winter.
"We're now transitioning assets to support the November launch of our next generation Mars rover, Curiosity," said Dave Lavery, NASA's program executive for solar system exploration. "However, while we no longer believe there is a realistic probability of hearing from Spirit, the Deep Space Network may occasionally listen for any faint signals when the schedule permits."