Officials are awaiting confirmation of the Rosetta probe’s collision into a 4km-wide ball of ice and dust.
The manoeuvre altered its wide orbit around the duck-shaped icy wanderer and put it on a direct collision course.
The crash velocity will be low, less than a metre per second, but Rosetta was never designed to land and so various components will almost certainly be crushed as it dumps down.
“Just to give you an example, if the high-gain antenna is off-pointing by more than half a degree then there is no communication possible anymore,” said Esa spacecraft operations manager Sylvain Lodiot.
Rosetta arrived at 67P/Churyumov-Gerasimenko – to give the comet its full name – in August 2014, after a 10-year journey from Earth.
In the 25 months the probe has lived alongside the mountainous object it has acquired more than 100,000 images and instrument readings.
These have provided an unprecedented insight into the behaviour of the comet, its structure and chemistry.
Rosetta even dropped a small robot called Philae on to the surface in November 2014 to gather additional information – a historic first in space exploration.
Comets are thought to be the near-pristine leftovers from the formation of the Solar System, and so all the data sent back from 67P will give scientists a remarkable glimpse into the conditions that existed four and a half billion years ago.
“We’re now entering the final stage of the space segment of the mission, if you like. But Rosetta’s data will be exploited for decades to come,” said Rosetta flight director Andrea Accomazzo.
With 67P currently 573 million km from the Sun, and moving further away daily, there is now precious little solar power to operate the probe’s systems.
Not only that – the data rates associated with that separation have become painfully slow: just 40kbps, akin to dial-up internet speeds.
Rather than put the probe into hibernation or simply let it slowly fade into inactivity, the mission team has determined that the venture should try to go out in style – as bittersweet as that may be.
“We’ve taken the world on a thrilling scientific journey to the heart of a comet and, in turn, we’ve seen the world take Rosetta and Philae’s amazing adventure into their hearts,” Mark McCaughrean, the senior science adviser at Esa, told BBC News.