Philae: Probe's historic comet landing

The Straits Times, 13 Nov 2014

LONDON - A probe the size of a washing machine has managed to make a historic landing on a comet in a mission to explore how these giant balls of ice, rock and dust contributed to the beginnings of life on Earth.

Europe's Rosetta spacecraft yesterday sent a probe to land on the comet, the culmination of a decade-long mission and 6.5 billion km of space travel.

After descending from its mothership, the lander touched down on Comet 67P/Churyu-mov-Gerasimenko at about 12.05am, Singapore time.

Comets have not changed much since the Solar System's formation 4.6 billion years ago, making them ideal for studying how the universe came into existence.

Apart from ice, comets are believed to contain chemicals that could have proved vital for the eventual formation of life on Earth.

Rosetta's landing craft, Philae, separated from its mothership at about 9.35am Paris time (4.35pm Singapore time), embarking on a long descent to the comet, according to a webcast on the European Space Agency's website.

The aim was to fire a harpoon to anchor itself.

Comet 67P/Churyumov-Gerasimenko is about 4km in diameter and the rendezvous with Rosetta is about 510 million km from Earth.

This is the first time a probe has landed on a comet. Mission control in Darmstadt, Germany, confirmed they were in contact with the probe several hours after it started its descent.

Rosetta, launched in March 2004, has been orbiting the comet since Aug 6 this year. Its 11 instruments have been monitoring the comet and gas and particles thrown off it as well as scoping out a suitable site to place Philae.

Rosetta is scheduled to orbit the comet until the end of 2015.

Philae, which has 10 instruments, will take pictures of the comet as well as drill 23cm below the surface to retrieve samples that can be taken up into the craft and heated.

The molecules that are released will then be analysed, said Mr Gerhard Schwehm, a consultant and manager of the mission from its lift-off until he retired from the space agency last year.

"This is the first mission that puts a lander down on a comet, so there are a lot of new opportunities to do science," he said.

"We will not find life, and we won't be able to answer the question tomorrow how did life emerge on Earth.

"But if we see organic molecules, we can say 'Oh, the comets could have brought very complex molecules to the early Earth.'"

The European Space Agency was formed in 1973 and has 20 member countries, including the United Kingdom, Germany and France.

Watch the video of the Rosetta Mission here.

BLOOMBERG, REUTERS

Space probe sends data from billions of miles away
European lander sends first-ever picture taken from surface of comet
The Straits Times, 14 Nov 2014

PARIS - Europe's robot lab Philae was "working well" on the surface of its host comet, though likely perched on a steep slope, ground controllers said a day after the probe made its historic landing.

Some data suggested that the washing machine-size probe may have touched down three times on the low-gravity comet, which is zipping towards the Sun at 18km per second, according to updates from ground control.

Philae's anchoring harpoons failed to deploy, but it still managed to send back scientific data for the European Space Agency (ESA) flagship mission as well as the first-ever picture taken from the surface of a comet.

The comet is shaped like a rubber duck, with two lobes measuring a few kilometres across.

"Philae is working well. Its battery is working well and is providing power," mission head Philippe Gaudon of France's CNES space agency said by phone from ground control in Toulouse yesterday. Photos the robot lab sent suggested "it is likely on a steep slope".

Mothership Rosetta, carrying Philae, was hoisted into space in 2004, and took more than a decade to reach its target in August this year, having used the gravitational pull of Earth and Mars as slingshots to build up speed. The pair covered 6.5 billion km together before Wednesday's separation and Philae's 20km descent.

The first signal confirming touchdown was met with jubilation at ground control in Darmstadt, Germany.

But this was soon replaced by worry when fluctuations in the radio signal indicated that the 100kg Philae may have lifted off again.

A tweet in the name of Philae's MUPUS on-board instrument said: "Magnetic analysis reveals 3 landings at 15:33, 17:26 & 17:33 UTC (GMT)."

"Short status update: we believe that Philae bounced (possibly three times) but sits safely on the comet now," said another at 0800 GMT.

Philae is the highlight of a massively complicated €1.3 billion (S$2.1 billion) project more than two decades in the making.

Equipped with 10 instruments, it is designed to carry out an array of experiments on Comet 67P/ Churyumov-Gerasimenko.

Scientists hope that samples drilled out from the comet by Philae will unlock details about how the planets - and possibly even life - evolved, as the rock and ice that make up comets preserve ancient organic molecules like a time capsule.

Comets date back to the formation of the Solar System some 4.6 billion years ago.

Mr Jean-Yves Le Gall, head of France's CNES space agency, yesterday reported "three pieces of good news" about Philae while a check-up was under way.

"Philae spent the night on the comet and we have three pieces of good news: The first is that Philae has landed on the comet," he said on Europe 1 radio.

"Secondly, Philae is receiving energy, its solar panels are activated and this allows it to envisage a future. Thirdly, we are in permanent contact with Philae, via Rosetta."

Philae was designed to operate for about 60 hours on a stored battery charge, but several months more with a sunlight boost. The lander complements 11 instruments aboard Rosetta, a three- tonne orbiter responsible for four-fifths of the expected scientific haul from its vantage point in orbit.

Whatever happens to Philae, Rosetta will continue to escort the comet as it loops around the Sun.

On Aug 13 next year, "67P" will come within 186 million km of the star.

The mission is scheduled to end in December next year, when the comet heads out of the inner solar system.

AGENCE FRANCE-PRESSE, BLOOMBERG, REUTERS




 

Philae sends precious data before 'zzzzz'
Robot lab's battery runs out of power after three days of non-stop work
The Sunday Times, 16 Nov 2014

Paris - Europe's science probe Philae sent home a treasure trove of data from a comet heading towards the Sun before falling silent as its power ran out, mission control said yesterday.

Crowning a historic feat, the robot lab streamed data from its experiments back to its mother ship Rosetta in the final hours before its battery ran down.

The data from the 1.3 billion euro (S$2.1 billion) mission included the outcome of an eagerly-waited chemistry test of a sample drilled from the comet's icy and dusty surface, scientists said.

"Rosetta's lander has completed its primary science mission," the European Space Agency (ESA) said.

Lacking power, its instruments and most of its systems went into standby mode after three days of non-stop work, sending back data that will keep scientists busy for years.

"The data collected by Philae and Rosetta is set to make this mission a game-changer in cometary science," said Dr Matt Taylor, the Rosetta project scientist.

Philae had landed in a dark shadow after a bouncy triple touchdown on Wednesday. It did not get enough sunlight to recharge its battery sufficiently to extend its mission beyond its initial 60-hour work programme.

"My #lifeonacomet has just begun," said an official tweet in the name of the washing machine-sized lander perched on comet 67P/Churyumov- Gerasimenko, before concluding with a restful "zzzzz".

"S'ok Philae, I've got it from here for now. Rest well...," said a response tweeted on behalf of Rosetta.

But mission engineers have not ruled out making contact with the lander in the coming months as the "67P" comet moves closer to the Sun.

Conceived more than 20 years ago, the Rosetta mission aims at shedding light on the origins of the solar system 4.6 billion years ago, and maybe even life on Earth.

A theory gaining ground in astrophysics is that the fledgling Earth was pounded by these bodies of cosmic ice and carbon-rich dust, seeding our planet with the basics to start life.

Rosetta and its payload travelled more than 6 billion km, racing around the inner solar system before they caught up with the comet in August.

Weighing 100kg on Earth, Philae has a mass of just 1g - less than a feather - on the low-gravity comet. That meant just a jolt could have caused it to drift off into space.

And lack of sunlight for its solar panels meant it had to survive on a battery with a charge of around 60 hours to carry out its scheduled scientific work.

Stacked against the odds, the scientists resorted to every trick possible to use power miserly and keep it working without causing it to drift away.

The "67P" comet is due to loop around the Sun next year, flaring gas from its head and leaving a spectacular icy trail of ice from water stripped from its surface.

Rosetta will escort it until the comet heads back out towards the depths of the solar system in December next year.

The team's eagerly-awaited first report will be made at a meeting of the American Geophysical Union in San Francisco next month.

AFP










* * *

Happy birthday Philae! We still love you, even if you did stop writing home.
Posted by I fucking love science on Thursday, November 12, 2015