Philae: Gone (probably), but not forgotten

12 Jan 2016

Hopes of communicating with Rosetta’s lander Philae are at their lowest now, with the ESA claiming “time is running out” to hear one last goodbye. The latest, and perhaps final, attempt to get it working has just failed.

It as been just over six months since Rosetta made contact with Philae, with 9 July 2015 now becoming a seminal date in the mission’s overall review.

Comet 67P, Philae’s final resting place, is soon to become “lander hostile”. The end of this month marks a shift on the comet from an operational environment into something far too cold to report from.

With that, Philae will be no more and the end of one of humankind’s greatest achievements will head towards its ultimate conclusion.

Losing all momentum

Of course, ESA scientists are still “exploring all possibilities” as they seek ways to jolt the lander back into life, but two days ago their last major attempt – when they tried restarting Philae’s momentum wheel – ended in failure.

Well, failure, in that no communication could confirm if it worked. Theoretically, Philae could have responded and moved to another spot but, with no way of finding out, that’s probably wishful thinking.

“We have to face reality, and chances get less and less every day as we are getting farther and farther away from the sun,” said lander manager Stephan Ulamec in New Scientist. “At some point, we have to accept we will not get signals from Philae anymore.”

A major point of consternation among the lander scientists is the likelihood that Philae has a bunch more readings from the comet that will never get uploaded to Rosetta, with that July communication far too brief to get anything across.

“It’s certainly a bit sad that we could not retrieve more data after the wake-up in June,” said Ulamec. “We have to live with the data that we got in November 2014.”

Mission: Impossible to criticise

This all sounds like doom and gloom, but lets not take away from the reality here: The Rosetta mission has been an incredible success.

It took a decade for Rosetta to reach its target, Comet 67P, tracking it through our solar system before taking up residency right beside it in late 2014. After taking a few snaps it sent Philae down (below) to investigate further.

Rosetta Philae

Philae’s landing was brutal and destructive, yet, ultimately, fortunate. It was fortunate in that, even though it crashed around a bit and was sent way off course, it landed at the very edge of what could be monitored.

This meant that some readings could be attained and sent back to Rosetta, before being received back here on Earth. But once the sun stopped shining on the lander it went to sleep and, but for a few occasional awakenings, it has lain dormant ever since.

Since the landing, numerous scientific papers have been produced on the back of dust grains and smells acquired by Rosetta (rotten eggs and marzipan, for some reason) – our understanding of comets, too, has skyrocketed.

Rosetta and Philae: a pair of bookworms

Rosetta is running out of juice, too, after such a long mission. Its plans make for entertaining reading, though, with a controlled landing onto Comet 67P coming some time this summer.

Though the plans are different to what become of Messenger recently, which now lies strewn across Mercury after a far more brutal descent.

“It will be less of a crash landing than the lander because we control it down,” the ESA’s Laurence O’Rourke told us recently. “In the end it will touch the surface, it won’t hammer the surface as it descends at 1cm per second, which is pretty slow.”

And with that the mission will finally reach an end. By the way, if you want to see what Comet 67P looks like then have a look at this website, which is so cool. Also, Rosetta is currently here, between Mars and Jupiter.

Here is a cartoon made by the ESA a few months back, when hopes remained that Philae would wake once more.

Main image of Philae on Comet 67P via ESA on Flickr

Gordon Hunt was a journalist with Silicon Republic