Philae comet lander is in shadow of cliff, may have battery recharging problems

[muriel_volestrangler]

The lander did receive some power from the solar panels on Wall No. 2 (technical description of the lander's solar walls here), but it appears that parts of the lander were in shadow during the time that last night's surface telemetry were being transmitted.

http://blogs.esa.int/rosetta/2014/11/13/philae-the-happy-lander/

From the recent press conference:

The first landing was on target, followed by a huge jump. The likely current location area of the lander suggests it may be facing the rim of a crater.
...
“The lander is relying on solar energy ... we’re getting one and half hours of sunlight when we expected six or seven. This has an impact on our energy budget.”
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Stephan Ulamec explains that activating any moving parts will be high risk, tipping the lander or pushing it away from the surface completely: “Drilling without being anchored is dangerous.” The same applies to any attempt to fire the harpoons.
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Jean-Pierre Bibring, however, points out that drilling to take samples for isotopic analysis is critical to the whole scientific purpose of the mission. With time running out, he hopes that this might be given the green light as soon as tomorrow.

http://www.theguardian.com/science/across-the-universe/live/2014/nov/13/rosetta-mission-philae-lander-live-coverage-comet-esa

Rosetta: concern over comet lander batteries

After showing an image that indicates Philae's location - on the far side of a large crater that was considered but rejected as a landing site - the head of the lander team Stefan Ulamec said: "We could be somewhere in the rim of this crater, which could explain this bizarre… orientation that you have seen."
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In any event, it may have risen vertically or drifted sideways - we should hear later. Either way, while Philae was off the surface, the comet will have rotated beneath it. Each rotation takes about 12 hours which means the lander may effectively travelled across one-sixth of the comet's surface.

By the time it came down again, the original landing zone - chosen for its relative safety and ideal amount of sunshine - was left far behind. The lander is now in different, undetermined area that may prove far more hazardous.

The first picture is confusing, but suggests Philae is sitting at an angle. Everyone here is hungry for more news.

http://www.bbc.co.uk/news/science-environment-30034060

[MannyGoldstein]

1. It sounds like a mistake

To assume that where ever the thing touched down would be a good spot.

Perhaps tiny thrusters could have been added so the thing could jump around until it found a good spot.

Maybe I'm misunderstanding what's going on...

[snooper2]

3. It just needs to go the third way around

[muriel_volestrangler]

4. The spot they selected for the original touchdown was good

The problem was they had a thruster designed to 'pin it down' when it landed, but they found, before it was released from Rosetta, that it appeared to have malfunctioned; they went ahead anyway (I don't know if they had an alternative). And the harpoons and ice screws didn't secure it (I wonder if deploying them may have been what got it to 'hop' away from the decent site - if they didn't 'bite', they may have pushed instead).

I suppose they could have designed it to have thrusters to try to move it around, but it's all extra mass for that, rather than scientific instruments, and it would all have to be run by the computer without input from Earth, since it's a hour round trip for the radio signals. They had to do the design without any pictures of what the comet is like, so it was all inspired guesswork anyway ...

[Baclava]

5. last image taken by lander before it tipped over

[IMG][/IMG]

[Baclava]

2. Is Rosetta's comet probe doomed? First picture from surface shows Philae has landed on its side

Without solar power it will die in 30 hours

Esa has confirmed they will make a daring attempt to save the Philae probe on the surface of comet 67P

According to Philippe Gaudon, who heads the Rosetta mission at the French space agency CNES, the probe is thought to be at an angle of about 30 degrees on the surface.

Eight of the ten instruments on board the spacecraft have also apparently taken data so far, but the solar panels seem to have been damaged during the dramatic landing.

The probe landed on the comet at around 3.30pm GMT yesterday but then bounced twice, first to a height of 0.62 miles (1km) and then to a much lower height before coming to rest. It is also thought to be about 0.62 miles (1km) from its intended landing site.

Esa confirmed in a statement that after the bounces rotated the probe around its vertical axis, which means it is now not upright on the comet.

This means that parts of the lander are in shadow but, they added: 'Nonetheless, the lander appears to be performing well.'

Philae only has around 20-30 hours of battery life in its main battery, before it will attempt to switch to rechargeable ones replenished by sunlight.

If it cannot get enough sunlight it will ultimately run out of power in at most 60 hours.

Mr Ferri says that all of the non-mechanical instruments on Philae are now working perfectly, but scientists will not be attempting to start up any of the mechanical instruments.

‘If we move something it might tip it over…once we know the attitude [angle], we will know what instruments we can use.

http://www.dailymail.co.uk/sciencetech/article-2832751/Rosetta-s-probe-stable-Philae-confirms-s-holding-67P-scientists-fear-tumbled-side.html

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oh well, it was fun while it lasted

[longship]

6. I don't believe this report. Daily Mail is a horrible source.

The ESA Blog states very clearly that Philae rotated with respect to the z-axis, which is a vertical rotation.

The Daily Mail sucks for writing that Philae is on its side.

[Baclava]

7. They were the only ones talking about it at the time - here's more

While it was touching down, the lander bounced twice -- almost as if the comet were a trampoline. The first bounce was major. It lasted almost two hours and took the lander about two-thirds of a mile above the comet's surface.

The second bounce was smaller and lasted just a few minutes, said Stephan Ulamec, the Philae landing manager. The craft's harpoons failed to attach it to the surface after touchdown Wednesday but it's now stable, scientists said.

"We know how we landed, but we don't know where," said Stephan Ulamec, Philae lander manager at the DLR German Aerospace Center. "We landed three times."

The lander then settled in a shadowy part of the comet near a cliff, where it is only getting 1 1/2 hours of sunlight a day. At its planned landing site, Philae would have gotten six or seven hours of sunlight.

The difference is crucial because Philae will need to rely on solar power after its batteries run out after about 60 hours, and this will affect how much work the probe can do on the surface, mission officials said.

Scientists also said Philae landed with two legs on the ground and one foot in the air during its final touchdown. Ulamec said the lander has the capability to make a little "hop" on the surface, which could help it get into a better position, but the maneuver would be risky and it is not likely ESA will try it.

And because Philae's harpoons failed to keep it tethered to the comet, ESA officials are also wary of drilling into the comet as planned. Their concern is that the force of the drills on such a low-gravity body could cause the lander to move again.

http://www.latimes.com/science/sciencenow/la-sci-sn-philae-update-20141113-story.html

[longship]

10. We'll see.

The ESA Blog says nothing about it being on its side.

[Baclava]

13. more like a 30 degree tilt according the ESA - one leg off the 'ground'

but hey - it stuck the landing, that's what this was all about

the engineers got it to land, the science is extra

[longship]

16. Thanks, that was about what I figured.

It's just too bad the thrusters and the harpoons did not function.

One is tempted to wonder if the first bounce was possibly caused by the harpoon firing. Probably not. But hey.

[ChisolmTrailDem]

8. All part of the process of discovery. That that probe is sitting on a comet is

one of the most amazing achievements ever accomplished by mankind.

To me, if Philae fell over the side of the comet today, it would still be a raging success.

[randome]

9. Well, then get going and moved the goddamned Sun!

Jesus, do I have to do everything around here?
[hr][font color="blue"][center]A 90% chance of rain means the same as a 10% chance:
It might rain and it might not.[/center][/font][hr]

[Baclava]

11. The Brits are on their way soon!

ESA sign big money deal with Astrium UK for Solar Orbiter

Solar Orbiter, the spacecraft has a target launch date of 2017. The launch vehicle of choice has not been named, although it was stated that NASA will contribute one full instrument, one sensor – and the launch vehicle



To get a close-up view of the Sun and to observe the solar wind before it becomes disrupted, Solar Orbiter will fly to within 45 million kilometres of the Sun, closer than Mercury. It will image the poles for the first time, helping ESA to understand how the Sun generates its magnetic field.

“Solar Orbiter is a fantastic mission,” added Prof. Cañete. “It will help us understand how the Sun, essential to almost all life on Earth, forms the heliosphere and the origin of space weather, which can have an enormous influence on our modern civilization


http://www.nasaspaceflight.com/2012/04/esa-sign-big-money-deal-astrium-uk-solar-orbiter/

[randome]

14. Man, what's that thing going to be made of to survive the heat?

It's amazing we can do things like this.
[hr][font color="blue"][center]Aspire to inspire.[/center][/font][hr]

[muriel_volestrangler]

12. Could be near another candidate landing site; will try hitting the comet hard to see if Philae moves

Engineers at Esa have calculated that the touchdown velocity was 1 m/s, slower than expected. Without the harpoons as anchors, Philae rebounded with a velocity of 38cm/s and conducted a leisurely jump for two hours.

In that time, it is now thought that Philae reached a altitude of about 1km and drifted about 1km away from the original site. On a comet of just 4km in length, that is quite significant.

The second jump was just for a few minutes and resulted in the lander coming to rest somewhere in the original landing site candidate known as site B.

http://www.theguardian.com/science/across-the-universe/live/2014/nov/13/rosetta-mission-philae-lander-live-coverage-comet-esa#block-5464ce3be4b0e5251178e8c5

The predictability of Newton’s laws has emboldened the scientists to deploy part of the MUPUS instrument tonight. This could cause Philae to shift, but calculations show that it would be in a direction that could improve the illumination.
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A new panoramic image will be taken after the MUPUS deployment to see if there has been any movement.

In parallel, there is a big effort from the Rosetta orbiter team to try to pinpoint Philae’s position. This will be done with images from the Osiris camera and with the CONSERT radar instrument.

CONSERT communicates with Philae. It is designed to be beam radar through the interior of the comet to reveal its internal structure. When Rosetta is directly overhead, CONSERT can provide highly accurate triangulation.

http://www.theguardian.com/science/across-the-universe/live/2014/nov/13/rosetta-mission-philae-lander-live-coverage-comet-esa#block-5464dd0ae4b0867bcfaf6458

MUPUS (Multi Purpose Sensors for Surface and Subsurface Science) consists of a number of temperature sensors attached to a 35 cm long penetrator that will be deployed away from the landing module. As the penetrator is hammered into the ground, the progress per hammering stroke and the temperature of the subsurface will be measured. In combination these will provide an indication of the properties of the comet’s surface (i.e. how resistant to penetration the surface is) and a profile of the temperature change with depth. The sensors can also operate in a heating mode which will allow the thermal properties of the comet (such as the heat conductivity) to be investigated.

http://www.open.ac.uk/science/research/rosetta/mission/philae-lander/mupus

[Baclava]

15. It bounced, it skeetered...and lived to tweet the tale

You know the lander is talking to u...


https://twitter.com/ESA_Rosetta

ESA Rosetta Mission @ESA_Rosetta .@Philae2-incredible panoramic postcard from the surface of #67P

[ChisolmTrailDem]

17. The second pic possible orientation of Philae is

exactly what I had imagined when I made this comment: http://www.democraticunderground.com/10025810591#post8

The little critter is literally standing (laying?) on the edge of a cliff, about to fall off.

I predict this craft will not remain there as the comet approaches the sun.

I am watching the latest from ESA recorded earlier today for the latest on the situation with Philae here: http://www.esa.int/Our_Activities/Space_Science/Rosetta/Rosetta_media_briefing_replay rather than depending on lay and stupid, and non-science-believing rightwingnut-leaning media sources and nooz/snooze dispensaries for their perspective.

[muriel_volestrangler]

18. Here's Emily Lakdawalla' annotated version of the 360 degree view:

So the lander is clearly tilted, with one image showing only sky. The lander has three legs, one in "front" and two to the side rear. The rear right leg is "down" in the image, while the front and rear left legs are up. Taken together with the geometry of the horizon -- which curves more than 180 degrees around the lander -- and it appears that the lander may actually be in a hole. When I imagined this, I laughed, imagining a comet jet suddenly popping Philae out of the hole like a pea from a straw. Or maybe an exogorth is down there somewhere! But, to get more serious, being in a hole would explain why the solar panels are getting so small an amount of illumination, and may unfortunately doom the lander to the short life dictated by its battery power.

What happens from here? They're doing as much science as they can without making any mechanical motions. That means no MUPUS surface properties experiments, or use of the APXS, and no deliveries to the gas chromatograph mass spectrometers. There is discussion of possibly using some of these moving devices to attempt to pop the lander up off the comet again, to try to get it into a position where they could recharge the battery. But if they do that, it will be a last-ditch effort.

http://www.planetary.org/blogs/emily-lakdawalla/2014/11131025-philae-status-a-day-later.html

[Baclava]

20. "What happens from here" - - the lander holds on for the ride of it's little robotic life!

The orbiter Rosetta will accompany the comet through perihelion (August 2015) until the nominal end of the mission.

[muriel_volestrangler]

19. Buzz sez: Get Your Ass to Mars

http://www.bbc.co.uk/news/science-environment-30048211

[muriel_volestrangler]

21. Summary, Friday 1525 GMT:

Simulations suggest battery power will last long enough for tonight’s data transmission from Philae.

Esa is considering whether to spin Philae’s flywheel to ‘bounce’ the lander into a new position where its solar arrays will get more sunlight to recharge its batteries.

80-90% of the intended science will have been carried out, but there’s some doubt over whether all the data will be uploaded before the lander loses all power.

All the lander’s instruments are working well. MUPUS and APXS instruments were used last night and the drill was activated. They will know this evening whether drill samples have been taken successfully. There will be more radar data to try to locate Philae.

http://www.theguardian.com/science/across-the-universe/live/2014/nov/14/rosetta-mission-philaes-third-day-on-comet-as-it-happens#block-54661ab8e4b0867bcfaf65ce

They also say that, as the comet gets closer to the sun, there's a possibility that the solar power will become enough to wake Philae up again.

[muriel_volestrangler]

22. 1st touchdown was within 10 metres of the target

The animated image below provides strong evidence that Philae touched down for the first time almost precisely where intended, a strong testament to the precision of the flight dynamics teams who planned Philae's journey down to comet 67P/C-G. It subsequently rebounded and, after touching down a second time, came to rest where it is now – a still unconfirmed location likely outside of these images.



...
The second image is 1 min 26 seconds after first touchdown. The touchdown is seen as a dark area. This dark area could be considered as strong indication that the lander touched down at this spot (possibly raising dust from the impact). The third image is the same as the second, but also shows a green square; this is the computed touchdown point.

They were taken from a distance of about 15 km from the surface, giving an approximate scale of 1.3 m per pixel. The dark spot appears to be within less than 10 m of the computed touchdown point.

http://blogs.esa.int/rosetta/2014/11/14/philaes-first-touchdown-seen-by-rosetta/

Not bad, aiming at a rotating target from 22.5km away, 7 hours earlier.

[muriel_volestrangler]

23. Comet lander: Philae sends data from surface

The Philae lander on the distant comet 67P has re-established radio contact with its orbiting Rosetta satellite and is sending data from the surface.

It ends a tense wait for the European Space Agency (Esa), amid fears that the lander's battery was about to die.

Scientists will be most keen to see if the probe has managed to get a surface sample of the comet with its drill.
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The first good news to emerge from the latest radio contact is that Philae appears to have suffered no major disruption from the drilling. And the instrument onboard the probe that was due to receive the first sample, Cosac, is feeding science data to Earth.

http://www.bbc.co.uk/news/science-environment-30058176

Batteries are on the point of running out:



https://twitter.com/Philae2014
https://twitter.com/esaoperations