The European Space Agency is ending the mission because 67P is racing toward the outer solar system, making charging of Rosetta's batteries increasingly challenging. The spacecraft also has been subjected to the harsh radiation and extreme temperatures of space since launching in March 2004 and is unlikely to last too much longer.
PHOTOS: Rosetta's Comet Gets its Day in the Sun
Rosetta will take a last look around as it descends to the comet's surface. Scientists have selected a landing spot on the smaller lobe of the duck-shaped comet, a region that contains many large, active pits. Lumpy structures known as "goosebumps," line the pit walls. Scientists suspect they may be remnants of primordial mini-comets that melded together to form 67P during the solar system's early days.
Rosetta will take close-up images of the pits and collect data about the dust, gas and plasma around them, its final contribution to an ongoing quest to learn more about the origins of the solar system and the development of life on Earth, and perhaps elsewhere.
"Rosetta has been a great mission and it will be sad when its telecommunications signal will soon be lost," said University of Washington astronomer Donald Brownlee, who led NASA's Stardust comet sample return mission.
RELATED: Rosetta's Comet is Fluffy Dust to the Core
"I was at Denver when we ran the fuel down to zero for the Stardust mission and the spacecraft slowly began to spin out of control. A hundred people were watching the big screen when the display showed a large 'LOS' for loss of signal. This is the way that spacecraft die," Brownlee told Discovery News.
ESA says confirmation of Rosetta's demise is expected at 7:20 a.m. EDT/11:20 GMT on Sept. 30, with the spacecraft set on a collision course with 67P the evening before.
GALLERY: 7 Intimate Close Encounters With Comets: