Alicia Chang reported today that, according to project manager John Callas, the last attempt to uplink a command to the Mars Exploration Rover Spirit will be made tomorrow. NASA will cease listening for signals from Spirit on Tuesday. While it would totally be in Spirit's character for her to wait until the last possible moment to make contact with Earth, even diehard supporters like rover driver Scott Maxwell are now admitting that Spirit has probably met her end.
More official word of the end being near comes from the NASA TV schedule, which now has this on it:
May 31, Tuesday
:30 p.m. - NASA Science Briefing: Mars Spirit Rover Celebration: An End to a New Beginning - HQ (Public and Media Channels)
So it appears that (in the immortal words of Hank Williams, Jr.) it's all over but the crying. There's bound to be some crying in the next couple of weeks. Spirit had a stronger hold on our hearts than most spacecraft manage to do.
Spirit hasn't disappeared, of course. We'll spot her from space with some regularity, through the HiRISE camera on Mars Reconnaissance Orbiter; it'll continue monitoring changing conditions at Spirit's landing site. As one of the few spots on Mars that's been imaged repeatedly by HiRISE, Gusev will continue to be a spot worthy of long-term monitoring. And every one of those monitoring images will feature a little lump that throws an unusually dark shadow, until (like Phoenix) her solar panels fall off. It may take a while for that to happen, though; JPL has a habit of building durable spacecraft, and (unlike Phoenix) Spirit's not likely to be encased in solid carbon dioxide any time soon.
Unlike nearly every other spacecraft we've ever sent to space, it's actually pretty likely that if humans ever manage to get ourselves off of Earth, someone or maybe a lot of people will see Spirit with their own eyes, seeing how her wheels were sunk into the soil near an extinct fumarole in the middle of a Martian crater. Maybe Spirit will be the center attraction of Gusev Crater Planetary Park some day. I hope so!