After Four Days, Philae Team Gets to Rest

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After Four Days, Philae Team Gets to Rest

Posted by timothy on Sunday November 16, 2014 @07:43AM from the beating-god-by-three-full-days dept.

The Associated Press reports on one happy consequence of the inevitable shutdown of the Philae lander, after its incredible landing on Rosetta: the team that was in control of the lander here on earth finally gets to take a well-deserved break, after four nearly sleepless days and nights. It seems unlikely -- though it's not impossible -- that Philae will get enough solar energy to briefly wake up again; its bouncy landing and harpoon malfunction mean that the craft is in shadow rather than the sunlight that it was hoped to bask in. From CNN: Originally, it was supposed to have seven hours of light per comet day -- which lasts just 12.4 hours. Now it is exposed only 1.5 hours a day. That's likely not enough to juice up Philae's rechargeable secondary battery, ESA said. There is one last hope. "Mission controllers sent commands to rotate the lander's main body, to which the solar panels are fixed," ESA says in on its blog. "This may have exposed more panel area to sunlight."

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RTG by Anonymous Coward · 2014-11-16 08:00 · Score: 1

Using an RTG would have eliminated this problem. Just saying...
1. Re:RTG by Ken_g6 · 2014-11-16 08:05 · Score: 3, Insightful
  
  It took ten years to get the Rosetta mission to the comet. By then a RTG would be fairly depleted too.
  
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2. Re:RTG by YrWrstNtmr · 2014-11-16 08:11 · Score: 3, Funny
  
  Thank you, Mr. Comet Lander designer guy! I'm sure, for the next one, they will bring you in as a consultant.
3. Re:RTG by 50000BTU_barbecue · 2014-11-16 08:15 · Score: 1, Troll
  
  Pretty sure having working landing gear would have solved the problem.
  
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4. Re:RTG by Lord+Crc · 2014-11-16 08:20 · Score: 2
  
  That would depend heavily on the radioactive material used, no? For example, Wikipedia lists Pu238 to have just a ~16% drop in output after 20 years.
  I'm guessing cost and weight were the key factors for picking solar over an RTG.
5. Re:RTG by Luckyo · 2014-11-16 09:21 · Score: 3, Insightful
  
  We are suffering from a severe shortage of Pu238 already. It's already one of the main limiting factors to NASA/ESA long range space exploration efforts.
6. Re:RTG by mister_playboy · 2014-11-16 10:56 · Score: 3, Insightful
  
  It's worth pointing out that the cause of this shortage is a political issue rather than a technical one. It started with a non-proliferation bill during the Carter era.
  
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7. Re:RTG by Anonymous Coward · 2014-11-16 11:26 · Score: 0
  
  There are multiple factors that cause RTGs to degrade, and a very significant one of those is that the thermocouple deteriorates. One could have stored the radioactive material apart from the Peltier / Seebeck elements and insert / assemble / fold the whole thing some time after arriving at the comet.
8. Re:RTG by Dan+East · 2014-11-16 12:21 · Score: 4, Informative
  
  It took ten years to get the Rosetta mission to the comet. By then a RTG would be fairly depleted too.
  That isn't a legitimate reason to not use RTG for Philae. The lander only uses 32 watts of power. The MMRTG used in Curiosity provides 125 watts of power initially, and 100 watts after 14 years. The mass of that specific RTG (the MMRTG) would be too great for use in Philae, but then it also produces 3 times more energy than needed (even after 14 years). RTGs have been made in many sizes for many different applications, so it would simply have been a matter of designing an RTG that produces 40-45 watts of power after 10 years.
  However, one of the main uses of the 32 watts of power required by Philae is just to keep the batteries warm so they don't fail. RTGs produce more "waste" heat than they do electricity. For example, the MMRTG used in the Curiosity rover produces 2 kW of heat, of which 125 W is converted to electricity. The extra heat is used to keep the various temperature-sensitive parts of the rover nice and warm so they don't fail. With Philae, a good portion of the 32 watts of the solar power it requires is just to keep the battery warm. So if an RTG were used, it wouldn't even need to produce 32 watts of electricity since it can keep the lander warm directly.
  Looking at the mass and wattage produced, the RTGs ("SNAP-19") in the Pioneer probes would have been just about perfect for Philae. They produce 40 watts of power and weigh 13.6 kg. Philae's current electrical system weighs 12.2 kg, so that's at least in the ballpark. The RTGs on the surface of the moon, as manually placed by Apollo astronauts's would have been a bit heavy at 20 kg. One of those RTGs was still producing 90% of its power after 10 years.
  Regardless, the fact that the Philae mission would last more than 10 years is not a reason to not have used RTG. Other issues (obtaining the radioactive material, environmentalists throwing a fit, inexperience of the ESA with that kind of power source, delays in production, etc) certainly dictated that an RTG wasn't used, but it was most certainly not due to any technical limitation.
  
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9. Re:RTG by trout007 · 2014-11-16 12:47 · Score: 1
  
  No. The Voyagers were launched in the late 1970's and are still functioning.
  
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10. Re:RTG by able1234au · 2014-11-16 12:50 · Score: 2
  
  Two problems. ESA does not have access to the plutonium as i understand it. The second issue is that it would have made the unit much heavier and so needed a bigger rocket to be able to meet the timelines.
11. Re:RTG by tomhath · 2014-11-16 13:23 · Score: 1
  
  The design of Philae was fine, it would have had enough power if the landing had gone as planned. The main thing they need to look at is why the attachment mechanism didn't work; fix that and there's no need for an RTG.
12. Re:RTG by Tablizer · 2014-11-16 16:05 · Score: 5, Funny
  
  It's amazing what they blame on Carter: A dead probe 40 years after his term.
  
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13. Re: RTG by Anonymous Coward · 2014-11-17 07:22 · Score: 0
  
  ESA don't have permission to use an RTG. It just wasn't an option.
14. Re:RTG by RockDoctor · 2014-11-17 17:31 · Score: 1
  
  RTGs were considered and rejected as too heavy for the power needed. You'll note that the large majority of the science programme was carried out, despite the unintended changes to operations.
  
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Questions for any who have been following this by QilessQi · 2014-11-16 08:05 · Score: 1

1. As the comet approaches the sun, is it likely that the angle of or proximity to the sun will provide enough light to make a difference?
2. I assume we've measured whether Rosetta is rotating, even slightly. Is there a chance that this will help (or hurt) Philae's chances at coming back on line?
3. As the comet gets closer to the sun, I imagine that it will start melting/vaporizing (this being what makes a comet look like a comet in the first place). Since Philae is not firmly anchored (and that might not make a difference in any case), what do we expect to happen, and when?

--
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1. Re:Questions for any who have been following this by duck_rifted · 2014-11-16 08:19 · Score: 5, Informative
  
  First things first.
  
  We've been calling this comet "Rosetta" thanks to the media, but it's actual name is 67P/Churyumov–Gerasimenko. Rosetta is the name of a probe that photographed it. But it does have a certain ring to it that may better stick in the minds of your average news reader.
  
  The comet has a rotation period of about twelve and a half hours. Its orbit lasts 2,398 days. We may be calling that a "Rosetta year" soon. To actually calculate whether the comet's orientation will allow sunlight to strike the main panels for longer stretches, we'd need to know more about the cliff it's under. The ESA is no doubt crunching those numbers now, but it's possible that if this situation will resolve itself then it will take years.
  
  A smaller panel got sunlight when the drill was used to rotate the probe. So, if it is powered down and we wait, it should eventually charge back up. Each time that happens, the ESA can work at getting it into a better position, little by little.
  
  It's not dead; it's just napping. It will eventually be back online. The big question is, when? If the ESA knew for sure, they'd probable tell us. So, we wait.
2. Re:Questions for any who have been following this by ColdWetDog · 2014-11-16 08:21 · Score: 1
  
  Just 'pining for the fjords' does have a certain sensibility about it in this case.
  
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  Faster! Faster! Faster would be better!
3. Re:Questions for any who have been following this by rvw · 2014-11-16 08:29 · Score: 2
  
  If it has 90 minutes a day sunlight, while it was expected to be 7.5 hours, wouldn't it just take five times longer? So maybe they could only use it once every five days (or whatever time unit they use). I'm not trying to be clever, just wondering why this doesn't seem to be an option.
4. Re:Questions for any who have been following this by mbone · 2014-11-16 08:29 · Score: 2
  
  1. As the comet approaches the sun, is it likely that the angle of or proximity to the sun will provide enough light to make a difference?
  2. I assume we've measured whether Rosetta is rotating, even slightly. Is there a chance that this will help (or hurt) Philae's chances at coming back on line?
  3. As the comet gets closer to the sun, I imagine that it will start melting/vaporizing (this being what makes a comet look like a comet in the first place). Since Philae is not firmly anchored (and that might not make a difference in any case), what do we expect to happen, and when?
  1.) Maybe.
  2.) If you mean Comet P/67, maybe.
  3.) Maybe, pretty much anything up to and including ejecting Philae away from the comet for good. As for when, maybe around perihelion (13 August 2015) when activity is highest. Or, maybe before then. Or after then.
  Glad I could help clear things up!
5. Re:Questions for any who have been following this by Lord+Crc · 2014-11-16 08:32 · Score: 3, Informative
  
  As I understand it, the problem is that the batteries must be at 0 degrees C to accept charge. The limited sun it's getting now isn't enough to heat the batteries (surface temperatures are about -70C IIRC).
6. Re:Questions for any who have been following this by confused+one · 2014-11-16 08:42 · Score: 4, Interesting
  
  It's not quite that simple. It takes a certain amount of power to keep the computer running, even in low power standby mode. It also requires some energy to run the onboard heaters, which keep the battery and electronics from failing due to the extreme cold. The amount of energy they were receiving in the 90 minutes, before the attempt to turn the probe, was insufficient to supply the heaters, run the computer in low power standby and charge the battery. I don't know if they left the heaters running, because there was concern that the heaters alone were enough to prevent the battery from charging. If not, the battery may freeze solid before charging to a level that's able to restart the computer. It's hoped that that won't be the case... we'll have to wait and see.
7. Re:Questions for any who have been following this by tinkerton · 2014-11-16 10:02 · Score: 1
  
  2. I assume we've measured whether Rosetta is rotating, even slightly. Is there a chance that this will help (or hurt) Philae's chances at coming back on line?
  The comet is actually rotating a lot, once every twelve hours. Since the comet acts as a gyroscope its axis of rotation keeps pointing towards the same distant star while the comet goes around the sun, and because the axis is tilted, different parts of the comet will receive light. The comet has seasons.
8. Re:Questions for any who have been following this by Anonymous Coward · 2014-11-16 11:40 · Score: 0
  
  So in other words, if it's properly designed, any solar energy received first gets sent straight to battery heating?
9. Re:Questions for any who have been following this by confused+one · 2014-11-16 14:27 · Score: 2
  
  No, if it's properly designed energy goes where the controller sends it. However, temperatures are low enough to freeze the battery, bringing it below the point where it will function. There are many electronic components that just won't work at -100C; or, will be damaged by deep cold. Heaters are critical to operation of most of the components on a deep space probes.
10. Re:Questions for any who have been following this by QilessQi · 2014-11-17 05:52 · Score: 1
  
  We've been calling this comet "Rosetta" thanks to the media, but it's actual name is 67P/Churyumov-Gerasimenko.
  Man, anyone who'd name their kid "67P" is just asking for that kid to be picked on. No wonder it prefers to go by "Rosetta".
  
  --
  Koans and fables for the software engineer
11. Re:Questions for any who have been following this by duck_rifted · 2014-11-17 07:43 · Score: 1
  
  Unfortunately, another poster has pointed out that the battery is freezing. Seems the fjords have iced over.
12. Re:Questions for any who have been following this by RockDoctor · 2014-11-17 17:08 · Score: 1
  
  A smaller panel got sunlight when the drill was used to rotate the probe. So, if it is powered down and we wait, it should eventually charge back up. Each time that happens, the ESA can work at getting it into a better position, little by little.
  Unfortunately, it doesn't work like that. A significant amount of power goes into heating the batteries up, which is necessary to get a significant amount of power out of (and in to) the batteries.
  Batteries are, as I'm sure you realise, chemical devices.
  All chemical devices operate at different rates at different temperatures.
  A popular rule of thumb is that a 10degree (Kelvin/ Centigrade) increase in temperature will double the rate of a reaction.
  These will be mollified as the comet comes closer to the sun. But working out the exact probabilities is just plain unpredictable. Plan 'B' of listening for "pings" regularly is indicated, while the rest of the science programme continues.
  
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Lander may wake up later by tinkerton · 2014-11-16 08:18 · Score: 1

A simple calculatoin:
Current amount of energy from panels is a quarter of what's needed
current distance from the sun is 3 earth units, it will go down to 1.3.
That means energy flux no the panels will increase (3/1.3)^^2 or more than 5 times.
If all the rest remains the same(er, what?), that should be enough.
And if the system can handle currents five times as high.
1. Re:Lander may wake up later by tinkerton · 2014-11-16 08:22 · Score: 1
  
  It'll drop to 1.25 actually. That's 5.6 times current flux.
2. Re:Lander may wake up later by Brett+Buck · 2014-11-16 10:00 · Score: 2
  
  That's possible, but the real issue is that the electronics are likely to be damaged by extremely cold temperatures.
Dead battery solution by Anonymous Coward · 2014-11-16 08:32 · Score: 0

Call AAA! They provide emergency roadside assistance, and will jump-start that battery in no time!
Just like grampa by Anonymous Coward · 2014-11-16 08:43 · Score: 0

It's not dead; it's just napping. It will eventually be back online. The big question is, when?

Just don't wake him. You wont like him when he's awake,
1. Re:Just like grampa by Provocateur · 2014-11-16 10:20 · Score: 1
  
  I hope nobody on the Philae team is named Jim. I'd hate to be that guy that wakes him up with the words "He's dead, Jim"
  
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Five pounds on eBay. by mbone · 2014-11-16 08:51 · Score: 1

While the Philae team is sleeping, nefarious malefactors are busy selling Philae on eBay. It's up to five pounds sterling as I write. Maybe we should wake them up.
1. Re:Five pounds on eBay. by Tablizer · 2014-11-16 15:31 · Score: 2
  
  I dig this one: "Buyer must collect item from its storage location on Comet 67P."
  
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It never landed on Rosetta by bugg_tb · 2014-11-16 08:51 · Score: 2

The article said it landed on Rosetta, if this was the case it wouldn't have been much use. Instead it landed on Comet 67P Churyumov-Gerasminko
Landing gif by SternisheFan · 2014-11-16 08:52 · Score: 4, Funny

This ESA blog link has a Gif of the landing from Rosetta... http://blogs.esa.int/rosetta/2...
1. Re:Landing gif by hcs_$reboot · 2014-11-16 20:41 · Score: 2
  
  Enhance!
  
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the dire equations by mbone · 2014-11-16 08:59 · Score: 1

From Valerie Lommatsch, an engineer at the Lander Control Center at DLR in Germany :

"It is very unlikely right now. We have 1.5 hours [of sunlight] at less than 1 watt, and 20 minutes of 3 or 4 watts. The lander needs 5 watts to boot....In order to charge the secondary battery, we have to heat it to 0 degrees Celsius. We need about 50-60 watt-hours a day in order to reach 0 degrees and still have daylight left to charge the battery. So it doesn't look that great. What we could hope for is if we are closer to perihelion, near 1 AU, maybe we could have enough energy on our one solar panel, maybe every once in a while"

So, they need 50 watt hours, and they are maybe getting 2. Now, this was before the 30 degree rotation, but I don't think that's going to get them a factor of 20 improvement. Maybe that, plus doing through perihelion, can do it.
I wonder if they couldn't get Rosetta near Philae, and use the reaction jets on Rosetta to move it (i.e., by blowing on it). Philae only weighs about as much as ping-pong ball; it wouldn't take much to move it away from where it is.
1. Re:the dire equations by Thagg · 2014-11-16 09:25 · Score: 1
  
  Sadly, while the "weight" is very small on the comet, it's mass (and therefore inertia) is substantial. You're not going to blow it over.
  It wouldn't surprise me if they land Rosetta on the comet toward the end of the mission.
  
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2. Re:the dire equations by mbone · 2014-11-16 09:43 · Score: 1
  
  It wouldn't surprise me if they land Rosetta on the comet toward the end of the mission.
  That is indeed under discussion.
3. Re:the dire equations by confused+one · 2014-11-16 10:00 · Score: 1
  
  The risk to Rosetta would not make such a maneuver worth trying. Use of propellant would also shorten Rosetta's life.
4. Re:the dire equations by mbone · 2014-11-16 10:05 · Score: 2
  
  Sadly, while the "weight" is very small on the comet, it's mass (and therefore inertia) is substantial. You're not going to blow it over.
  I am going to ignore for now any issues of damage from nearby thruster firings.
  Rosetta has 24 bipropellant 10 N thrusters and is 2.8 x 2 m, not counting solar panels. Philae is 1 x 1 x 0.8 m. Suppose Rosetta fires a thruster from 3 meters away - Philae is then 1/3 of a radian across, or about 0.1 steradians. Suppose the thruster has a exit angle of 2 pi steradian (i.e., the whole hemisphere away from the spacecraft, which is surely conservative). So, I would expect Philae to experience a force of 10 N x 0.1 / 2 pi ~ 0.2 N. It has a mass of ~ 100 kg, so that would impart a thrust of 2 x 10^-3 m/sec^2. (I am assuming Rosetta has a thruster firing on the opposite side too, so it's not moving.) That is actually greater than the 67/P gravity, so Philae could move. If this were done for say 10 seconds, Philae would have a velocity of ~ 1 cm/sec afterwards and maybe a total flight time of 30 seconds. Now, it wouldn't move far, but it might get to a little flatter terrain and maybe more sunshine.
5. Re:the dire equations by wooferhound · 2014-11-16 10:45 · Score: 1
  
  Not to mention that they don't know where the lander is.
  
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6. Re:the dire equations by mbone · 2014-11-16 10:58 · Score: 1
  
  Not to mention that they don't know where the lander is.
  I think it is a safe bet it will be found. They have the photos from the surface, they have the CONSERT triangulation, and of course they have a great desire to find it (and the comet isn't that big). It will be found.
7. Re:the dire equations by zippthorne · 2014-11-16 13:01 · Score: 1
  
  Your math doesn't include the remaining delta-v budget of those 10N thrusters...
  
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8. Re:the dire equations by f3rret · 2014-11-16 22:12 · Score: 1
  
  I wonder if they couldn't get Rosetta near Philae, and use the reaction jets on Rosetta to move it (i.e., by blowing on it). Philae only weighs about as much as ping-pong ball; it wouldn't take much to move it away from where it is.
  That's a Kerbal solution if I ever read one.
  
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9. Re:the dire equations by Muad'Dave · 2014-11-17 05:06 · Score: 1
  
  I know everyone hates armchair rocket scientists, but I'd like to leave this here:
  
  A ~0.2 kg block of pure Gd148 (~1 inch^3) initially yields ~120 watts, sufficient in theory to meet the complete basal power needs of an entire human body for ~1 century ...
  They could've had 120W of heat free for the asking with 200g of Gd148 (a pure alpha emitter). Use 50W of that to keep the wee beastie warm, and the other 50-ish Watts might've been enough to power the lander.
  
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10. Re:the dire equations by Anonymous Coward · 2014-11-17 05:55 · Score: 0
  
  That says nothing of the cost of using that, or even what the worldwide inventory of the isotope is. Gd-148 is often strictly limited in a lot of experiments that involve isotope production, as the most hazardous to health of the isotopes produced in certain kinds of sources. Stuff like spallation sources are limited to what amounts to about 50 mg within a much larger metal target, and at least in the US, only about 5 mg of it was isolated and sold in a year. This would be a considerably more difficult and substantially more expensive source of heat than the already logistically difficult plutonium based RTGs that they found impractical.
11. Re:the dire equations by RockDoctor · 2014-11-17 17:12 · Score: 1
  
  I think they've found it already, to a couple of Philae-diameters.
  
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Longer charge times by Anonymous Coward · 2014-11-16 09:47 · Score: 1

seven hours of light per comet day -- which lasts just 12.4 hours. Now it is exposed only 1.5 hours a day.

So 7 hours of light should provide enough energy for ~12 hours of operation, which it was planned would allow it to function every day.
Surely though the 1.5 hours will be enough for it to wake up for a short period of time? Long enough to upload some new instructions.
If they leave the lander in sleep mode for several comet days they can gain enough energy for a longer period of operation. Sleeping for 5 comet days will give the equivalent of charging for 5x1.5 = 7.5 hours, roughly what they expected in a single day. Surely that's then enough to get a full day's operation on the 6th day? Sure the science will take longer, but they can still get plenty done on those days?
1. Re:Longer charge times by wooferhound · 2014-11-16 10:47 · Score: 1
  
  There is some power being used by some of the systems even when the lander is in standby mode
  
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Design flaws by Taco+Cowboy · 2014-11-16 10:49 · Score: 0

Pretty sure having working landing gear would have solved the problem

These are all Monday morning quarterbacking, but truth is that all of us should learn from the unfortunate design mistakes that ESA has made
Working landing gear is one, but a bigger design flaw is that they (the ESA probe landing team) assumed that they could land the probe on a comet just like they land a probe the size of the Moon or Mars
All they have, before they release the probe, was a series of GO / NO GO checklist, on the few chosen "preferred landing spot" on that comet
There was no contigensy plan for the many "what ifs" that may happen
And the design of their probe (the shape of it) is exactly like the probe others have used on Mars / Moon - a box with a few legs beneath it
Instead of design the probe with a shape that could deal with more "what if" scenario --- that might greatly enhance the survival of the probe if the probe ended up in non-optimal spots
And the power supply --- why send up a thing to a piece of flying rock in space, chase it for 10 long years, and by the time the space craft reaches the destination, it only has hours of power supply left??
The ESA Rosetta mission turns out to be a showcase of a series of what _not_ to do if one wants to launch a space probe to space

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1. Re:Design flaws by jareth-0205 · 2014-11-16 11:30 · Score: 2
  
  All they have, before they release the probe, was a series of GO / NO GO checklist, on the few chosen "preferred landing spot" on that comet
  There was no contigensy plan for the many "what ifs" that may happen
  Do you have any reason to believe this, any actual evidence that there wasn't a long list of contingencies, or are you just making it up? Because I certainly don't know all the inner workings of the ESA, and since you've provided no links then I somewhat doubt that you do either.
2. Re:Design flaws by Anonymous Coward · 2014-11-16 12:39 · Score: 0
  
  assumed that they could land the probe on a comet just like they land a probe the size of the Moon or Mars...There was no contigensy plan for the many "what ifs" that may happen
  Just because they did not have alternatives did not mean they assumed such things could not happen. There were a lot of known risks for the lander, some of which were deemed acceptable, especially considering the battery life would be enough for the vast majority of the instruments and data they were planning for. While operating longer would have been nice for the 3 out of 10 instruments that could keep going, that main emphasis of the project was by far the orbiter. The lander design reflects this, especially when it was scaled back at one point.
3. Re: Design flaws by SilenceBE · 2014-11-16 20:33 · Score: 2
  
  assumed that they could land the probe on a comet just like they land a probe the size of the Moon or Mars
  
  Which is factually incorrect. Saw a documentary about this project yesterday and they were fully aware of the difference hence the harpoon and screws to try to keep the lander intact.
  
  They even described the "what if" scenario if the harpoons would fail, but it doesn't help if the lander rest in a place where there isn't enough sunlight. That is just plain unfortunate.
4. Re:Design flaws by f3rret · 2014-11-16 21:51 · Score: 1
  
  Pretty sure having working landing gear would have solved the problem
  These are all Monday morning quarterbacking, but truth is that all of us should learn from the unfortunate design mistakes that ESA has made
  I don't really see how saying "If the thing that did not work, had worked, everything would have been fine" constitutes "Monday morning quarterbacking". I mean, it's stating the obvious for sure, a completely useless statement for sure, but I don't think it's a hindsight/20/20 thing.
  
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5. Re:Design flaws by Anonymous Coward · 2014-11-16 21:54 · Score: 0
  
  The part of the mission involving the probe was planned to achieve its aims within the battery life. (60hrs) It appears to have done this - staying alive longer is actually the 'what if' scenario. Not sure you can actually point to a design mistake yet?
  What is likely to be the more significant part of the mission is the fact that Rosetta will continue to orbit and monitor the comet through its closest approach to the sun and hopefully contribute to understanding comet behaviour as the tail forms.
6. Re:Design flaws by Anonymous Coward · 2014-11-17 05:15 · Score: 0
  
  lol... Slashdot, never change. The points raised by the various blowhards are occasionally valid (through the huge benefit of hindsight), but the sheer casual arrogance and pomposity is truly jaw-dropping.
"after four nearly sleepless days and nights" by antdude · 2014-11-16 11:06 · Score: 1

Wait, everyone was like that? How can one/1 work like that? :/

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1. Re:"after four nearly sleepless days and nights" by trout007 · 2014-11-16 12:49 · Score: 2
  
  If you have worked for a couple decades on a project I imagine it would nearly impossible to sleep.
  
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2. Re:"after four nearly sleepless days and nights" by Anonymous Coward · 2014-11-16 15:05 · Score: 0
  
  I've done that kinda thing for software projects I had poured a lot less of my heart and soul into and the stakes of which were a lot less final.
  I doubt that they were literally up for 4 straight days, but 4 days catching a couple hours at their desk when they could, definitely believable. I've never done 4 days without going home, but 3 for sure, and 48 hours is probably pretty common amongst programmers in general.
  Also that feeling when you are finally done, even if you failed (which btw I don't think they did at all) is pretty damn incredible. You get home and know you can sleep as long as you want.
3. Re: "after four nearly sleepless days and nights" by Anonymous Coward · 2014-11-16 19:52 · Score: 0
  
  I wouldn't be able to sleep at all. ESA is an EU structure and failure in the EU is severely punished (unless you're into politics). If ESA's PR department can't spin it positively (and it's going to be hard, with the current economic crisis hitting hard millions of families the populace isn't keen on spending on "space science"), heads will roll. The first to go will be the guy in the funny shirt. Witness what happened to the neutrino research team after the FTL fiasco which was mainly the media's fault but they embarassed an Italian minister so they had to pay the price. No, failing in the EU is a career-ending event.
4. Re: "after four nearly sleepless days and nights" by Anonymous Coward · 2014-11-17 05:24 · Score: 0
  
  That was in Italy. Italian culture and customs are vastly different than those elsewhere in Europe.
5. Re:"after four nearly sleepless days and nights" by RockDoctor · 2014-11-17 17:27 · Score: 1
  
  The key word is "nearly" ; most people who haven't had to do it on a regular basis are surprised to learn that you can function on quite small amounts of sleep. You do still need some sleep, and your performance degrades over time, but it's not too drastic.
  My normal working day is 18-19 hours, but when we're in critical operations I go down to working about 03:00 to 12:00, have a nap after lunch, then am back on shift from 13:00 to about midnight ; lather, rinse repeat. After a week, you're really looking forward to a solid 5 hours sleep, but you can get by, and make decisions and react to unplanned events during that time.
  That's oilfield operations, and generally not safety critical (I don't operate cranes or powered equipment, for example) and it's not preferred to working a 12-12 hour shift pattern. But if that's what the manning provided requires, that's what you do.
  
  --
  Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"
6. Re:"after four nearly sleepless days and nights" by antdude · 2014-11-17 17:37 · Score: 1
  
  So, you do this daily?
  
  --
  Ant(Dude) @ Quality Foraged Links (AQFL.net) & The Ant Farm (antfarm.ma.cx / antfarm.home.dhs.org).
7. Re: "after four nearly sleepless days and nights" by RockDoctor · 2014-11-18 03:03 · Score: 1
  
  When I'm at work, and we go from routine operations (where I have a lot to do) to evaluation operations (where I have a lot to do and can't delegate chunks of it to my night-shift/trainee, because they're a trainee) then yes, I have to do this regularly. Bouts of 4-5 days are normal; up to 8 days not uncommon, but deeply draining. Then there will unavoidably be 1-2 days of engineering/ maintenance work, and then the cycle repeats. Bouts like this happen a couple of times a month, then I'm rotated back to shore or my home country to recover.
  Don't get me wrong- this is draining. But it's not impossible.
  OTOH, there is a good reason that 90% of trainees move on to office work instead of staying in field work : a lot of them can't handle the fieldwork.
  
  --
  Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"
8. Re: "after four nearly sleepless days and nights" by antdude · 2014-11-18 04:51 · Score: 1
  
  Wow, how long have you been doing this? Is it worth it? I used to work long hours and even worked about a month nonstop (no days off). It wasn't worth it. Ugh.
  
  --
  Ant(Dude) @ Quality Foraged Links (AQFL.net) & The Ant Farm (antfarm.ma.cx / antfarm.home.dhs.org).
9. Re: "after four nearly sleepless days and nights" by RockDoctor · 2014-11-18 07:35 · Score: 1
  
  I've been doing this since 1987, to varying degrees. Some years I've been down to about 1500 hours work (though we bill by the day, or part of, door to door), some years pushing 3000 hours, and utterly exhausted. The intensity increases with time, because you get sent to jobs with absolute greenhorn (instead of being the greenhorn yourself). And sometimes you do have to just dump raw data upstream for assessment there, but even then you need to verify that the collection parameters were recorded appropriately.
  (An 8h x 5d x 48w year is 1920 hours. On the other hand, when I'm not at work, I can go for a week hill walking if I want, and there's nothing the Boss can say - it's my compensatory time for sleeping at the work site and being on 24x7 call.
  
  --
  Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"
10. Re: "after four nearly sleepless days and nights" by antdude · 2014-11-18 07:47 · Score: 1
  
  Nice. You still get paid to sleep at work. I wish I could do that! ;)
  
  --
  Ant(Dude) @ Quality Foraged Links (AQFL.net) & The Ant Farm (antfarm.ma.cx / antfarm.home.dhs.org).
11. Re: "after four nearly sleepless days and nights" by RockDoctor · 2014-11-18 09:23 · Score: 1
  
  I also get paid to be prepared to climb into the lifeboats, or go to the drill floor to deal with unexpected events. A wake up 2 hours after a 17 hour shift is not welcome, but is part of the job.
  
  --
  Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"
12. Re: "after four nearly sleepless days and nights" by antdude · 2014-11-18 09:40 · Score: 1
  
  That's nuts. :(
  
  --
  Ant(Dude) @ Quality Foraged Links (AQFL.net) & The Ant Farm (antfarm.ma.cx / antfarm.home.dhs.org).
13. Re: "after four nearly sleepless days and nights" by RockDoctor · 2014-11-18 13:03 · Score: 1
  
  That's the job. Many of my trine es go on to supervise or plan such jobs. They leave me with no doubt of the drain they put on people. And, in my experience they remember, and fight a corner for 24x7 experienced cover. But if the people aren't there to hire, and the bed space isn't available ... then at least they understand the problems of the (person)in the field better. It's not perfect, but it's better than nothing.
  
  --
  Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"
RTG by Voice+of+satan · 2014-11-16 11:15 · Score: 1

ESA doesn't have its own RTGs yet. Access to plutonium is a problem and the use of americanium 241 for future EU RTGs is planned. Since US nuke regulations forbid to sell such technology unless it is installed at the last moment on US soil which would imply US acces to EU industrial secrets and a launch from US soil with a US rocket it is out of the question for ESA to buy a RTG on the shelf.
Plus ESA has a much lower budget than ESA and doesn't have as many deep space missions As the NASA. Yet.
Except for one man... by Anonymous Coward · 2014-11-16 11:37 · Score: 5, Funny

...who will be heckeled by feminazis until they find someone or something else to attack.
1. Re:Except for one man... by Anonymous Coward · 2014-11-16 17:12 · Score: 1
  
  I'd like to show support for the man that did this comet landing thing.
  Anybody know where I can get a copy of his shirt?
2. Re:Except for one man... by Anonymous Coward · 2014-11-16 20:27 · Score: 0
  
  Wasn't it a custom made gift to him?
3. Re:Except for one man... by Anonymous Coward · 2014-11-16 22:11 · Score: 0
  
  They're sold out: http://www.alohaland.com/whats-new/new-gunner-girls
4. Re:Except for one man... by Anonymous Coward · 2014-11-17 01:26 · Score: 0
  
  That's not the same shirt however - AC above was correct, it was in fact made as a gift by a friend - and she's been getting as much flack for being a traitor to all women! https://twitter.com/ellypriZeMaN/status/532927131098300416
Rest...Rest in Peace by slas6654 · 2014-11-16 11:45 · Score: 0

Rest in peace lil space junk washing machine. We hardly knew ye'.
Shine it by Anonymous Coward · 2014-11-17 00:47 · Score: 0

Could not they shine some sunlight by bouncing light on Rosetta's solar panels?
Questions for any who have been following this by Anonymous Coward · 2014-11-17 01:15 · Score: 0

"As the comet gets closer to the sun, I imagine that it will start melting/vaporizing (this being what makes a comet look like a comet in the first place)"
Finding out what really happens and how and why is one of the mission objectives.
Sweet by Impy+the+Impiuos+Imp · 2014-11-17 02:36 · Score: 1

> After Four Days, Philae Team Gets to Rest
Thank god. I have this comfy shirt I've been meaning to wear...

--
(-1: Post disagrees with my already-settled worldview) is not a valid mod option.
Explain to me... by Anonymous Coward · 2014-11-17 04:14 · Score: 0

Why can't they just let the lander sit 7 times longer than expected to fully charge the batteries? Is the power drain at the lowest power it is capable of drain more than it can charge in that time?
1. Re:Explain to me... by Anonymous Coward · 2014-11-17 05:56 · Score: 0
  
  As was already answered several times above, the batteries won't charge if they are too cold, so there is a minimum amount of power needed for heaters before the batteries can start accumulating energy.
RTG by Anonymous Coward · 2014-11-22 12:29 · Score: 0

Now average this over a day on a body and you'll see RTG can be smaller.