The Phoenix lander, a plucky geologist unlocking many mysteries of Mars, is laboring away and still producing rich scientific finds as it faces a death sentence, NASA briefers said this afternoon.

Since the hardy lander still is able to work, its mission has now been extended into October. Originally, it was designed to work only 90 Martian days, or sols, after its May 25 landing on Mars.

As the frigid Martian winter approaches, Phoenix — now sitting in a far north Arctic region — is receiving less and less sunlight on its solar arrays to power its electrical systems, even as it uses more and more electricity to try staying warm and awake in longer nights.

Finally, the sun will sink out of sight, and Phoenix will run out of power, its busy life cut short.

But it will have achieved a major success first, NASA briefers told journalists in a news conference this afternoon.

The Jet Propulsion Laboratory still is receiving solid scientific information from Phoenix, briefers said.

Briefers said that no one anticipates Phoenix will be able to survive the Martian winter, even though next year warmer weather and sunlight will return to it.

The slide to an early end of its life already is evident: while at one time Phoenix was receiving 3,500 watt-hours per Martian sol from its solar arrays, now it is harvesting just 2,100 watt hours per sol.

But Phoenix will go out a winner, briefers said. It found water on Mars, which is hugely vital to any future human presence there. Water can provide astronauts with drinking water, oxygen to breath and hydrogen to heat homes and offices and fuel for vehicles.

And now, Phoenix has found chemicals such as perchlorate and calcium carbonate on Mars. The calcium carbonate find was verified by two different types of tests in its on-board laboratories, briefers said.

That’s interesting, because calcium carbonate is formed when a certain gas combines with liquid water, further signs of H2O on Mars.

And calcium carbonate is better known as the chalk used on blackboards, and as an anti-acid.

Maybe it will help astronauts avoid indigestion.