Space agency says Philae completes primary mission

Space agency says Philae completes primary mission
Rosetta's OSIRIS wide-angle camera image released by the European Space Agency ESA on Thursday Nov. 13, 2014 shows the position of Rosetta's lander Philae Wednesday, before it landed on the surface of Comet 67P/Churyumov-Gerasimenko. Source digitally added a circle to mark the landers location. The lander scored a historic first Wednesday, touching down on comet 67P/Churyumov-Gerasimenko after a decade-long, 6.4 billion-kilometer (4 billion-mile) journey through space aboard its mother ship, Rosetta. The comet is streaking through space at 41,000 mph (66,000 kph) some 311 million miles (500 million kilometers) from Earth. (AP Photo/Esa/Rosetta/Philae)

The pioneering lander Philae completed its primary mission of exploring the comet's surface and returned plenty of data before depleted batteries forced it to go silent, the European Space Agency said Saturday.

"All of our instruments could be operated and now it's time to see what we got," ESA's blog quoted lander manager Stephan Ulamec as saying.

Since landing Wednesday on comet 67P/Churyumov-Gerasimenko some 311 million miles (500 million kilometers) away, the lander has performed a series of scientific tests and sent reams of data, including photos, back to Earth.

In addition, the lander was lifted on Friday by about 4 centimeters (1.5 inches) and rotated about 35 degrees in an effort to pull it out of a shadow so that solar panels could recharge the depleted batteries, ESA's blog said.

ESA spokesman Bernard von Weyhe on Saturday confirmed the lander's difficult rotation operation. It's still unclear whether it succeeded in putting the solar panels out of the shade.

Even if the lander was rotated successfully and is able to recharge its batteries with sunlight, it may take weeks or months until it will send out new signals. Regular checks for signals will continue.

The agency did not schedule any media briefings on Saturday.

ESA's mission control center in Darmstadt, Germany, received the last signals from Philae on Saturday morning at 0036 GMT (7:36 p.m. EST Friday). Before the signal died, the lander returned all of its housekeeping data as well as scientific data of its experiments on the surface —which means it completed the measures as planned, the ESA blog said.

During a scheduled listening effort on Saturday at 1000GMT, ESA received no signals from Philae, ESA's mission chief Paolo Ferri told The Associated Press.

Space agency says Philae completes primary mission
This image from Rosetta's OSIRIS narrow-angle camera, released by the European Space Agency ESA on Nov. 13, 2014 shows the Philae lander on Nov. 12, 2014 Philae landed Nov. 12, next to a cliff that largely blocked sunlight from reaching its solar panels on the 4-kilometer-wide (2.5-mile-wide) 67P/Churyumov-Gerasimenko comet. The head of the European comet mission says scientists will listen for signals from the Philae lander Saturday Nov. 15, 2014 but think it is unlikely they will establish any kind of communication soon. Controllers at the European Space Agency on Friday ordered the lander to perform a maneuver intended to pull it out of a shadow on the comet so that solar panels could recharge the depleted batteries. "We don't know if the charge will ever be high enough to operate the lander again," Paolo Ferri, ESA's head of mission operations, told The Associated Press. (AP Photo/ESA,File)

"We don't know if the charge will ever be high enough to operate the lander again," Ferri had told The AP ahead of the 1000GMT (5 a.m. EST) listening time. "It is highly unlikely that we will establish any kind of communication any time soon."

Now it's up to ESA's team of scientists to evaluate the data and find out whether the experiments were successful—especially a complex operation Friday in which the lander was given commands to drill a 25-centimeter (10-inch) hole into the comet and pull out a sample for analysis.

"We know that all the movements of the operation were performed and all the data was sent down" to ESA, Ferri said Saturday. "However, at this point we do not even know if it really succeeded and if it (the drill) even touched the ground during the drilling operation."

Material beneath the surface of the comet has remained almost unchanged for 4.5 billion years, so the samples would be a cosmic time capsule that scientists are eager to study.

The lander did already return images of the comet's surface that show "it is covered by dust and debris ranging from millimeter to meter sizes," while "panoramic images show layered walls of harder material," ESA's blog stated.

The science teams are now studying their data to see if they have succeeded in sampling any of this material with Philae's drill.

Beyond analyzing the new data, scientists are also still trying to find the exact spot where Philae landed on Wednesday.

"The search for Philae's final landing site continues, with high-resolution images from the orbiter being closely scrutinized," the blog said.

Scientists hope the $1.6 billion (1.3 billion-euro) project will help answer questions about the origins of the universe and life on Earth.

One of the things scientists are most excited about is the possibility that the mission might help confirm that comets brought the building blocks of life—organic matter and water—to Earth. They already know that comets contain amino acids, a key component of cells. Finding the right kind of amino acids and water would be an important hint that life on Earth did come from space.

"The data collected by Philae and Rosetta is set to make this mission a game-changer in cometary science," Matt Taylor, ESA's Rosetta project scientist, was quoted as saying on the blog.


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No signals heard from comet lander Saturday

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Nov 15, 2014
Why only one mission? The world's annal GNP is $101.2 trillion--30 $1.6 billion space probes could be funded from merely one second of that.

Nov 15, 2014
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Nov 15, 2014
Space agency says Philae completes primary mission
This is how the failed mission can be transformed into successful mission in the eyes of publics.


You're an idiot.

Nov 15, 2014
"Material beneath the surface of the comet has remained almost unchanged for 4.5 billion years"

Can this be proven in any way?

Nov 15, 2014
Why not equip philae with a nuclear battery for contingencies such as these? Why rely only on sunlight? Kind of disappointing.

Nov 15, 2014
as stated before; they thought about it but lacked knowledge of the technology to put it into a very small lander which is in sleep mode for over 10 years, thats something you not gonna find in russian storehouses..

Nov 15, 2014
Space agency says Philae completes primary mission
This is how the failed mission can be transformed into successful mission in the eyes of publics.


All its experiments were designed to be run with the power of the primary battery within the first 64 hours.

How did it fail?


Nov 15, 2014
as stated before; they thought about it but lacked knowledge of the technology to put it into a very small lander which is in sleep mode for over 10 years, thats something you not gonna find in russian storehouses..


RTGs need constant cooling, which would have required thermal radiators, which would have caused the Pioneer anomaly where the slight radiation pressure from the heat emission could have changed the velocity of the craft by about 1 m/s over 10 years in space.

If not properly accounted for, that could have put the craft some 16,000 km off target on rendezvous with the comet.

Nov 15, 2014
There aren't any straightforward ways to accurately correct the trajectory give the rad pressure? I would assume there is some kind of course correction going on at given intervals to eventually hit the target...

Nov 15, 2014
as stated before; they thought about it but lacked knowledge of the technology to put it into a very small lander which is in sleep mode for over 10 years, thats something you not gonna find in russian storehouses..

RTGs need constant cooling, which would have required thermal radiators, which would have caused the Pioneer anomaly where the slight radiation pressure from the heat emission could have changed the velocity of the craft by about 1 m/s over 10 years in space.
If not properly accounted for, that could have put the craft some 16,000 km off target on rendezvous with the comet.
Both of these are things that you need to take into account when using a nuclear battery, but they're not the reason why one wasn't used. The team flat out stated that they thought it would be a great idea, but that they couldn't do it because of public resistance in much Europe to nuclear anything. Europeans (France excluded) are afraid of anything with the word "nuclear".

Nov 15, 2014
talk about saving face on a likely failed, at the very least stalled, mission.

they couldn't avoid bouncing this awesome lander into the shade???
sad.

for all the fools out there that like to talk about 'asteroid mining' , enjoy reality while it sinks in how difficult zeroG operations and maneuver is on a comet or rocky body.

Nov 15, 2014
Europeans (France excluded) are afraid of anything with the word "nuclear"


Germans are, for internal political reasons. Others not so much.

ESA just happens to be mostly controlled between France and Germany, with others playing a more stagehand role in their operations.

With Germany being far the biggest single contributor to its funding, they also have the most political control over it. So it was rather "no nuclear or no money" from the big G.


Nov 15, 2014
There aren't any straightforward ways to accurately correct the trajectory give the rad pressure? I would assume there is some kind of course correction going on at given intervals to eventually hit the target...


The problem with the radiation pressure is that it's extremely difficult to model, given that the radiation reflects from the satellite body in complex ways.

The Rosetta satellite itself flew in hibernation to save on fuel and power during the 10 year stint, so they put the craft in a spin to use the mass of the satellite as a gyroscope wheel, so that when it woke up it would be pointing in a predictable direction and could point its antennas back to earth.

Had there been some unpredictable force acting on the craft, it would have messed up the spin, and it would have had to be woken up many times to check direction, which would have required more fuel mass and a heavier more expensive launch, or less scientific payload.


Nov 15, 2014
And those constant course corrections result in somewhat unpredictable changes in the final trajectory of the satellite, because every time you fire a thruster to re-adjust the attitude of the craft, it adds to its velocity and then you have to re-calculate where it's going, and fire more thrusters to correct it, and re-correct... etc. etc. which is why the Voyager crafts had a rather large margin of error in their trajectories - but they weren't trying to hit comets. They were aimed at planets.

Or add massive reaction wheels to turn it, like with the Cassini craft. But that was a much bigger, much more expensive probe that was a joint operation between ESA, NASA and ASI.

Nov 15, 2014
Ah I see. Thanks for the clarification. Sounds like we need solar system GPS. They should throw some beacons on the moon, and in orbit around the earth. That plus the sun should be enough to allow for easier deep space nav. :)

Nov 16, 2014
Without the knowledgeable here flaming me out of existence permit the following question:
Don't shadows moved?

Nov 16, 2014
move=moved
Flüchtigkeitsfehler. Sorry.

Nov 16, 2014
Don't shadows moved?
@russell_russell
this is not a bad question
the shadow will move depending on the source of the light and whatever is blocking the light
in this case, the path of the asteroid may still bring it around to get some sunlight, but that might not be enough, and it also depends on where the cliff is in relation to the lander

we know, from the article and ESA that it is fairly close and that the lander was only moved a small way
the lander was lifted on Friday by about 4 centimeters (1.5 inches) and rotated about 35 degrees in an effort to pull it out of a shadow
what is needed now is a signal confirming that it worked
It's still unclear whether it succeeded in putting the solar panels out of the shade.
Even if the lander was rotated successfully and is able to recharge its batteries with sunlight, it may take weeks or months until it will send out new signals. Regular checks for signals will continue
does that help/answer you?

Nov 16, 2014
move=moved
Fl�Ľchtigkeitsfehler. Sorry.
@russell_russell
jeder macht Fehler von Zeit zu Zeit. Dies ist kein Problem.
Ich beschuldige meine Fehler wie die auf "große Finger".

Post Script, um oben: der Asteroid bewegt sowie dreht, und dies ermöglicht es die Schatten sich zu bewegen, aber nur, wenn ausreichend Platz vorhanden ist so dass die Platten Zugang zum Licht. Es hängt alles davon ab, wie der Lander sitzt in Bezug auf die Lichtquelle und das, was zwischen ihm und der Quelle (die Klippe)
Ich hoffe, das macht die Dinge klarer für Sie. Ich beschloss, die Verwendung von Google Translate, um auch helfen

Ich hoffe, das hilft Ihnen zu verstehen

Nov 16, 2014
Much obliged - CS.
Great answers.
Does this comet even have an axis of rotation?
Specifically. The erratic loss of mass wreaks havoc on any axial rotational motion.
That is my homework. Of course feel free to answer - I hate homework.

Nov 16, 2014
Without the knowledgeable here flaming me out of existence permit the following question:
Don't shadows moved?


They originally planned for the lander to be exposed to the sun for between 6-8 hours a day, which would allow it to warm up the secondary battery and recharge it for an extra 1 hour of full operation each day.

Now it seems like they could be getting only about 2 hours of sunlight a day, which means there might not be enough to keep the battery warm, and if there is it will take several days to a week to reach enough charge to start communicating.

If the battery goes cold and cannot be recharged, there's the possibility that the watchdog circuits that are responsible for the upkeep will slowly drain it completely and the battery will be damaged to the point that it can't be recharged later on when the comet turns closer to the sun, and the lander will never wake up again.


Nov 16, 2014
So much for redundancy. The moral of the story is, don't put all your eggs in one basket.

Seriously though, who the hell decided on solar power?

Nov 16, 2014
"One of the things scientists are most excited about is the possibility that the mission might help confirm that comets brought the building blocks of life—organic matter and water—to Earth."

Yes, but it looks like they can be excluded as a major contributor of volatiles. They have the wrong nitrogen isotope ratios. While hydrogen, carbon and nitrogen ratios fit inner disk material for Earth, Moon, Vesta, Mars.

@antomina: It is the life histories of Kuiper Belt Objects (this comet) or Oort cloud objects (long period comets). Of course collisions will make local heat, which is why we see so many amino acids in asteroids and comets. Maybe molecular clouds make them too, but there is no spectroscopic evidence for all of them yet.

@russell: The location before the head rotation/leg extensions was giving the panels ~ 20-40 minutes of direct sunlight IIRC. The comet gets closer to the Sun too. Might eventually help.

Nov 16, 2014
The comment editor is broken, making them even shorter than usual. Since I had to separate in two I can add:

Not having much volatiles with comets support the early cold, wet Earth Jack Hill zircons tell us of. And it would up both exoplanet habitability and habitation (more time) to have them delivered with the disk as it made planetesimals such as Vesta and Mars. Further, modern emergence theories differ from soup theories in that they build biomolecules from the ground up. (But of course delivery is still a possible co-option path.)

I'll hope the Rosetta mission can confirm the isotope ratios, which may all have been spectroscopic before this.

@indio: Having the solar panels were redundant, they were to be used for mission extension. Philae did its primary mission, hopefully with the drill successful or else Philae catching ambient volatiles.

Why is answered many times in the thread.

Nov 16, 2014
@xtos: "Sounds like we need solar system GPS. They should throw some beacons on the moon, and in orbit around the earth."

Unfortunately those would be expensive systems, and give massive antennas over interplanetary distances for small crafts.

Scientists have come up with something that promises to be better. Remember the pulsar orientation map that was put on the Voyagers (and Pioneers, I think)? A miniaturized radio or optical set (they can use variable stars too, and I can't remember their choice) can pinpoint crafts more precisely and with less onboard mass than a sparse, delayed GPS net can do. IIRC NASA is working on it.

Nov 16, 2014
There already IS a Positioning system in Space. They are called pulsars.

Nov 16, 2014
Europeans (France excluded) are afraid of anything with the word "nuclear"


That's not true. There is preliminary work being done to produce European RTG's possibly not with plutonium but americium, potentially utilising Sellafield or French processing infrastructure. Also not the ESA/RKA Exomars lander will be RTG powered.

Note Germany still operates research reactors there is nothing to suggest this would be any different.

Nov 16, 2014
More great answers. Thanks everyone.
@CS Raised bilingually. I translate research if asked.The last translation was experimental physics. Suspended free floating cylinder axial motion in a rotating viscous fluid.

Nov 16, 2014
... Seriously though, who the hell decided on solar power?
A politically correct bean-counter too much influenced by Michio Kaka on the Cassini/Huygens mission decision to use RTGs.
Given that RTGs use PU238 which is a very scarce resource, why should we waste it when solar power is available? Here is a good article on RTGs: http://www.spaces...issions/

Nov 17, 2014
Given that RTGs use PU238 which is a very scarce resource, why should we waste it when solar power is available?


It's not necessary to use plutonium in RTGs.

Plutonium is chosen because it produces high heat at 560 W/kg and low gamma emissions, but its output drops relatively quickly with a half-life of 87 years.

If you use Americum, you need four times as much to account for the lower activity, but it practically never stops. It has a half life of over 400 years, so the output drops off more smoothly. The satellite would have nearly as much power 100 years from now.

The EU has a large arsenal of decaying Pu-241 from civilian reactors, which is breaking up into Americum-241, so there's a cheap supply of it, and they have to separate it because the increasing portion of Am-241 in the plutonium is slowly making it infeasible for recycling as nuclear fuel.

Nov 17, 2014
Currently, worldwide production of Am-241 is only a few kilograms per year, most of which is already used to fill demand for smoke detectors and moisture gauges. BNSC space science director David Parker says that Harwell (ESA's new facility in the UK) will study Americium as an alternative to Pu-238, and Oxford University is researching infrared-related technology as an alternative conversion solution.
This quote is strait from the link I provided.

Nov 17, 2014
If they had a solar panel that was tethered to the lander that was detachable so that it could be "launched" away from the lander into a sunny spot, wouldn't that have worked as a shade contingency?

Nov 17, 2014
If they had a solar panel that was tethered to the lander that was detachable so that it could be "launched" away from the lander into a sunny spot, wouldn't that have worked as a shade contingency?

Nov 17, 2014
If they had a solar panel that was tethered to the lander that was detachable so that it could be "launched" away from the lander into a sunny spot, wouldn't that have worked as a shade contingency?

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