An engineer involved with the Rosetta spacecraft says he's excited about the prospect of seeing it crashed into a comet - even though it means killing off his creation.

On September 30, scientists at the European Space Agency will make the "bold manoeuvre" of trying to land the Rosetta spacecraft on Comet 67P which it has been chasing for 12 years.

The crash will see the Rosetta descend on to the ball of rock and ice made of the original building blocks of the universe in a flurry of last-minute photographs and scientific analysis.

But landing it is only half the story, according to space engineer Simon Barrowclough, who helped design the thermal system on the Rosetta that kept it alive during 31 months spent in hibernation.


Once the Rosetta lands, its communication system will be shut down lest it keep trying to transmit to Earth and interfere with future missions.

"They want to do this bold manoeuvre of actually trying to land on it," said the Canberra-based space research engineer at the University of New South Wales. "In doing so, as it becomes closer they can do more [great] science.

"There're certain concerns that if it crashes and only partly fails it may try and transmit but we can't talk to it and that can cause interference with other future missions.

"So we have to basically make it passive, they have to turn it off and dispose of it but before they do that they want to try and get the last bit of science out of the spacecraft."

It's a suitably dramatic end for the longest and most expensive mission in space history, described as the "gold standard" in comet research.

After launching in 2004, Rosetta went into hibernation for 31 months, being kept just warm enough by Barrowclough's thermal design to avoid a total shutdown.

It was woken by an "internal alarm clock" when it moved closer to the sun and has been tracking the comet ever since.

The mission went slightly askew in November 2014 when Rosetta's lander Philae - deployed to rove the surface of the comet - "bounced" on impact and became wedged in a crevasse. After three days its battery died and the rover was lost until this month when it was spotted wedged into a crack on the comet's surface.

Barrowclough said the miraculous find in the nick of time would allow scientists to work out the structure of the comet based on radio signals transmitted back to Earth through the comet's interior.

But far from feeling despondent about the end of the 12-year mission, Barrowclough said it was exciting to see what the next stage will bring.

"It's just reality, it's come to its end, it's done the job.

"It's actually quite exciting because no one really talked about this idea of trying to land it on the surface before and it's actually quite exciting to see them try and do that and what might happen with that."