18 ms·

Our lander’s asleep

392 points by jonnyscholes 12y ago

valevk 12y ago
What kind of data did the lander gather, and will it be open to the public?
- vixen99 12y ago
  It had better be given that the public paid for it at a minimum cost of 1.4 billion Euros for the strictly European input.
  - sz4kerto 12y ago
    It will be given to the public -- in contrast to 99% of scientific research results published by private companies like Elsevier making you pay $30 per article (or less, doesn't matter: you must pay to get the results of a research funded by you). Edit: most of it will be, not everything, as I've just found out.
    - vixen99 12y ago
      Completely agree. It is outrageous. I am researching a topic at the moment and expected to pay £20 for the privilege of viewing a paper (with work funded as you say, by the taxpayer) published in 1960. As to the project, the cost (open to correction by all means) was 1.4 billion. Downvote if you like; evidently this is my big mistake for not understanding that facts are apparently unwelcome hereabouts. If people assume that by mentioning this sum I am necessarily disapproving of the project then they are simply wrong and indeed had not one iota of evidence to suppose that. Now I know better - 'I must not mention the cost in case something thinks I am moaning about it'.
      - Anon84 12y ago
        Just let me know what you need. I'm happy to forward to you anything I can get through my university access. I'm sure others here are willing to do the same so we should have most things covered.
  - dingaling 12y ago
    Much of the Rosetta data is under embargo, because the instruments were not paid for by ESA but private organisations like Max Planck Institute. Hence the paucity of hard data released to the public; the organisations have first dibs on the data to make their money back through publications and in attracting research funding. As an example: http://www.mps.mpg.de/1979387/MPS-Beteiligungen_an_Rosetta http://www.mps.mpg.de/1979387/MPS-Beteiligungen_an_Rosetta Basically, ESA provide the bus on which the science kit rides. As an EU tax-payer I've raged against this in the past but that's just the way it is. Source: direct question on this matter that I put to an ESA PR at a public lecture about Rosetta.
  - danmaz74 12y ago
    Yes, it would have been much much better for us Europeans to use that money to subsidize our agriculture a bit more... /s
- Maxious 12y ago
  The data should appear on http://www.sciops.esa.int/index.php?project=PSA&page=rosetta http://www.sciops.esa.int/index.php?project=PSA&page=rosetta and http://pdssbn.astro.umd.edu/data_sb/missions/rosetta/index.shtml http://pdssbn.astro.umd.edu/data_sb/missions/rosetta/index.s... and http://nssdc.gsfc.nasa.gov/nmc/datasetSearch.do?spacecraft=Rosetta http://nssdc.gsfc.nasa.gov/nmc/datasetSearch.do?spacecraft=R... The lander data includes infrared imagery, x-ray spectroscopy results, electrical conductivity measurements, temperature readings (from harpoons), acoustic data, gas analysis and magnetometer data http://nssdc.gsfc.nasa.gov/nmc/experimentSearch.do?spacecraft=Philae http://nssdc.gsfc.nasa.gov/nmc/experimentSearch.do?spacecraf...
  - valevk 12y ago
    Thanks for the references! Do you happen to know when the first results (verified interpretations of the data) are usually published after such experiments?
anvandare 12y ago
Anthropomorphizing machines somehow always manages to twang my emotional snares. http://xkcd.com/695/ http://xkcd.com/695/ Good night, little lander. Hope you dream of electric sheep.
- Pyrodogg 12y ago
  If you like that xkcd, this'll twang a few more heartstrings. Imposter by The Doubleclicks https://www.youtube.com/watch?v=pHU67s5tOSA https://www.youtube.com/watch?v=pHU67s5tOSA
- codeonfire 12y ago
  When did machines begin tweeting as themselves? I find it odd as there are usually lots of tweets that no person would make such as "scientists are sending commands to repair my body." or "soon technicians will install new parts into me."
  - IndianAstronaut 12y ago
    Welcome to the world of PR.
  - prawn 12y ago
    This is one way you take science to the masses. I think giving each Philae instrument its own Twitter account is a great idea.
    - StavrosK 12y ago
      I find it pretty deep in the uncanny valley.
      - prawn 12y ago
        I wonder if you are not the target audience?
- DodgyEggplant 12y ago
  http://www.youtube.com/watch?v=ayM68-4EioY#t=925 http://www.youtube.com/watch?v=ayM68-4EioY#t=925
ThePhysicist 12y ago
“Each night, when I go to sleep, I die. And the next morning, when I wake up, I am reborn.” - Mahatma Gandhi Let's hope it will wake up and be reborn. The chances for this seem not that bad, since the comet will heat up considerably as it approaches the sun, which will make it unnecessary to preheat the interior of Philae before starting to charge the batteries, while at the same time increasing the solar power reaching the panels (due to the sun being closer), so the lander might actually generate enough power to recharge the batteries and come alive again. Let's keep our fingers crossed.
- raverbashing 12y ago
  They also managed to rotate the lander so it gets more sunlight
  - ThePhysicist 12y ago
    Yeah right, let's hope this helps as well! Of course there's the possibility that the panels will get more sunlight as the angle of the comet's rotation axis changes respective to the sun.
- maaku 12y ago
  That's one of the most scary quotes ever. Way to write a horror story in 2 sentences.
  - blrgeek 12y ago
    If you've never thought about sleep that way, you should be scared! How do you know the person who woke up this morning is the same person who went to sleep last night?
    - bronson 12y ago
      How do you know the person who clicked the "Reply" button is the same person who wrote those words?
    - 12y ago
bitwize 12y ago
Do not go gentle into that good night, Philae. Rage, rage against the dying of the light.
- shdon 12y ago
  You made me look up that poem. I hold you responsible for the tears it brought.
stinos 12y ago
Everytime I read about tech like this I cant help but wonder What kind of mainboard does this run? What CPU? What temp spec? what OS does it run? What is the main laguage? Would it use open source code? Anyone has a clue or educated guess? edit thanks to all answers provided, exactly the info I was looking for! And very interesting as well.
- acqq 12y ago
  Regarding the power source, and why the mission depended on only solar energy: "Why was RTG (Radioisotope thermoelectric generator) not used in Rosetta mission?" https://news.ycombinator.com/item?id=8610585 https://news.ycombinator.com/item?id=8610585 Only US and Russia have the technology.
- pjmlp 12y ago
  Most likely Ada, C or C++ with very strict code guidelines, which even make C feel like Ada. Alongside real time OS like VxWorks, QNX, Aonix, .... There was a presentation at CppCon about Mars Rover. https://www.youtube.com/watch?v=3SdSKZFoUa8 https://www.youtube.com/watch?v=3SdSKZFoUa8
- fjarlq 12y ago
  Some details: http://space.stackexchange.com/questions/593/on-board-computer-data-handling-system-of-rosetta-details http://space.stackexchange.com/questions/593/on-board-comput... Note that the RTX2010 uses Forth: http://en.wikipedia.org/wiki/RTX2010 http://en.wikipedia.org/wiki/RTX2010
- duckson 12y ago
  I don't know about Philae/Rosetta's hardware in particular, but there are very specific requirements to hardware that's sent into space. I'm using the Mars Science Laboratory as an example here: The MSL uses twin PowerPC RAD750 boards. If one of them fails, the rover could use the other as a backup. After all, you can't go out to Mars to fix a firmware update gone wrong. :) The RAD750's are hardened against radiation in space, and can withstand extreme temperatures. They run at about 200Mhz, and cost around $200.000 a piece. [1] [2] It runs the realtime operating system VxWorks, which also happens to be what Apple uses for their Airport routers. :) [3] NASA uses C as their main language, with specific coding standards. [4] [1] http://en.wikipedia.org/wiki/Mars_Science_Laboratory#Rover http://en.wikipedia.org/wiki/Mars_Science_Laboratory#Rover [2] http://en.wikipedia.org/wiki/RAD750 http://en.wikipedia.org/wiki/RAD750 [3] http://www.extremetech.com/extreme/134041-inside-nasas-curiosity-its-an-apple-airport-extreme-with-wheels http://www.extremetech.com/extreme/134041-inside-nasas-curio... [4] http://lars-lab.jpl.nasa.gov/JPL_Coding_Standard_C.pdf http://lars-lab.jpl.nasa.gov/JPL_Coding_Standard_C.pdf
justsee 12y ago
As late as 12 November, the ESA's own FAQ [1] was stating that Philae's minimum mission target was one week of surface operation (powered entirely by primary batteries), with even more operational time powered by back-up batteries (themselves recharged by solar) - resulting in an expected surface operation period measured in months. They airbrushed the FAQ on 12 November to remove mention of the minimum one week mission target, and inserted among other things '2.5 days'. [2] A diff of the two versions would probably be interesting. Now with the lander mission prematurely ended an associated scientist is tweeting a very rosy summary [3]: "What a perfect ending. All the science completed, data received. Primary mission successful. Well done everybody." How can a week of carefully-planned scientific activities be 'completed' in only 2.5 days? It seems implausible. How did the primary and secondary batteries not power the lander for the calculated one week+ of operation? Why aren't they open about what clearly seems to be a major failure with the scientific mission? It seems a case of intense bureaucratic / political pressure to change targets after they aren't met, and the fact scientists are participating in this is pretty disappointing. [1] https://web.archive.org/web/20140805030451/http://www.esa.int/Our_Activities/Space_Science/Rosetta/Frequently_asked_questions https://web.archive.org/web/20140805030451/http://www.esa.in... [2] http://www.esa.int/Our_Activities/Space_Science/Rosetta/Frequently_asked_questions http://www.esa.int/Our_Activities/Space_Science/Rosetta/Freq... [3] https://twitter.com/rocketeddy/status/533421309553016832 https://twitter.com/rocketeddy/status/533421309553016832
- acqq 12y ago
  The targets have to change during the mission. The initial plan was even the another comet. It shouldn't matter. http://en.wikipedia.org/wiki/Rosetta_%28spacecraft%29 http://en.wikipedia.org/wiki/Rosetta_%28spacecraft%29 "Rosetta was set to be launched on 12 January 2003 to rendezvous with the comet 46P/Wirtanen in 2011. This plan was abandoned after a failure of the Ariane 5 carrier rocket during a communications satellite launch on 11 December 2002, grounding it until the cause of the failure could be determined." No reason to blindly stick to the initial target when you're doing something for the first time ever. It's not that you planned to drive from your home to the shopping mall and have to excuse to your other that you went drinking beer instead. You would probably complain that it's not an initial comet now too? The device landed on the darn comet! After travelling 6 billion km in 10 years. Managed to work a few days and send the data! First time ever! Powered only by the solar energy! (+) In the outside temperature of absolute zero. How many firsts do you need? https://www.youtube.com/watch?v=uEY58fiSK8E https://www.youtube.com/watch?v=uEY58fiSK8E Nothing built by humans was ever on the comet surface before. This thing even worked. +) Edit: Thanks to jdiez17 for pointing that the lander used a non-rechargeable battery on the comet surface. It was all the time planed to do the main work with that battery. The solar powered work wasn't the primary objective.
jordanthoms 12y ago
It appears to be largely political issues that prevented this mission from using a Radioisotope thermoelectric generator , which would have eliminated this particular problem since solar panels would not be required. [1] This is how the Curiosity rover is powered. If that is the case it's a massive shame - irrational fear of nuclear technology does a lot of damage. 1 - http://www.space4peace.org/ianus/npsm2.htm#2_3 http://www.space4peace.org/ianus/npsm2.htm#2_3
- acqq 12y ago
  The first (failed) mission to Mars was attempted as early as 1960 by the USSR, continuing with 1964, 1965 Mariner by the US. Rovers came after a lot of previous work done, including a lot of unsuccessful attempts. And the rover weights 900 kg, probably 40 kg of it is the nuclear power generator. Philae is only 100 kg and the first on the comet. It's certainly not "fear" of the nuclear technology in Europe that prevented something. See for example: http://en.m.wikipedia.org/wiki/Nuclear_power_in_France http://en.m.wikipedia.org/wiki/Nuclear_power_in_France It's that the engineering tradeoffs have to be considered.
  - guscost 12y ago
    While it seems perhaps uncharacteristic of a space agency to make engineering decisions based on politics, if I had to guess I'd imagine that the team was well aware of the PR effect of the power supply chosen for their lander. I would also guess that the same issue was considered at NASA while planning the Mars Exploration Rover (solar) and Curiosity (RTG) missions. Are you claiming that this did not factor into their decision at all?
    - NeverEnough 12y ago
      that it wasn't a significant factor, at least
      - guscost 12y ago
        Fair enough. I don't know nearly enough about Europe or the ESA to volunteer an over/under on that.
tete 12y ago
I'm really curious about the results. This is the first time something like this has happened, but with the results, actually knowing a lot of variables, not even from the lander itself other missions will have something to base their work upon. The first programming languages (static, duck typed, ...), database systems, web frameworks, anonymization frameworks, ... all had a lot of things that were either far from perfect or are now considered stupidity. But when nobody did what you did, when you are a pioneer everyone following would be a fool not to look at your work. Also a nice example: Operating Systems. In the early days they were considered a waste of energy, time, resources. Why would you want to emulate computers on other computers (no, not visualization, but running multiple programs) or why would you use that valuable memory/storage space to have multiple programs on a machine at once? Those used to be actual questions. But that's a bit far fetched. The project was/is a real pioneering project and I have lots of respect for people investing all their lives (more than two decades in this case!) so passionately into landing on a comet. Not too long ago that was science fiction. The first message on the internet (arpanet) was meant to be "login", but it crashed after the o. I think those people got further, even though without doubt it didn't run as hoped for.
erre 12y ago
Rosetta wouldn't have some mirrors, or even reflective surfaces, would it? It could position itself to reflect sunlight onto Philae. I mean, I'm sure Rosetta has neither (in useful conditions), but there's a thought for next time :/
- sylvinus 12y ago
  This was asked in a French Q&A session with the ESA and they dismissed it as "science-fiction" :) http://www.lemonde.fr/sciences/article/2014/11/13/philae-peut-transmettre-des-informations-tant-qu-il-dispose-de-puissance_4523384_1650684.html http://www.lemonde.fr/sciences/article/2014/11/13/philae-peu...
  - erre 12y ago
    Well, I meant it more as "hopeful pondering", but point taken :)
- Ono-Sendai 12y ago
  That would be possible in theory, a few problems though: You would need a flat surface to reflect light towards Philae, so the only appropriate surface would be the solar panels. The solar panels are not mirrors however, they would probably only reflect about 5%-10% of the sunlight towards Philae. This is even assuming the solar panels are sufficiently flat. Also the location of Philae is unknown (AFAIK), so there is the problem of where to aim the reflected light. Finally the relative direction from Rosetta would presumably change as the comet rotates, which means the solar panels or Rosetta as a whole would need to be continuously aimed at Philae, using propellant and/or other energy.
- thyrsus 12y ago
  Apollo retroreflectors. https://www.xkcd.com/1441/ https://www.xkcd.com/1441/
splitbrain 12y ago
I assume that Philae isn't meant to be powered directly by sunlight but has an intermediate battery? So wouldn't it make sense to simply wake him once this battery is full, do some experiment, send the data and go back to sleep until recharged again? Shouldn't that work even with low light conditions, just that the sleep phases would be much longer than planned? The article sounds like they aren't sure Philae will ever wake up again.
- acqq 12y ago
  The space is unbelievably cold. The lander is in the shade, meaning the temperature there is probably mostly at least around minus 60 degrees. The battery has much higher operating temperature.
  - waps 12y ago
    It's actually unknown whether there's an atmosphere there. Temperature in space is very cold, sure, but if there are no gas collisions nothing carries the heat away (like, say, on Antarctica). So the lander would only really be cold where it touches the comet, and the comet actually gets quite hot at times. Wikipedia mentions that Haley's comet was 70 degrees celcius (above zero) last time it passed by Earth. Despite geostationary satellites operating in an environment that's nominally -265 or so degrees celcius, the problem they usually experience is overheating, not freezing. Blackbody radiation will eventually carry the heat away, but we're talking decades to get to -100 or so. For instance, a human body at rest generates about 150 watts of power, which would kill you in geostationary orbit without a cooling system. It would kill you because it wouldn't take long for your body temperature to rise to 52 degrees, at which point your cell metabolism abruptly stops (your mitochondria will stop generating energy). It would take longer than it takes you to choke though. Though nobody's ever tried for obvious reasons, you should be able to exit a space station and get back in with just a helmet that protects your mouth and nose and ears from decompression. You wouldn't freeze, you wouldn't explode. You'd overheat in 10-15 minutes or so. If you survive that, you'd die 2 weeks later from radiation poisoning. On the moon you need heating, because it actually has an atmosphere that would carry heat away. It is fun reminiscing about just how special our place in the universe is. Human bodies wouldn't be able to survive on planets 30% closer to the Sun, or about 15% farther away. We wouldn't be alive without a mostly oxygen atmosphere, because without the ozone layer, solar radiation would kill us. Without the earth magnetic field, solar radiation would kill us. Without the sun protecting us from interstellar radiation, we'd die. If our solar system was further to the outside of the milky way, we wouldn't survive the radiation, solar protection or not. If it was closer to the middle, we wouldn't survive. It's unknown whether it's a black hole at the center or something else, but it sure outputs a lot of radiation. Oh, and we're in the < 0.1% of the milky way that hasn't experienced a supernova explosion for about 3 billion years (a supernova explosion at 20 lightyears or less would kill all life on earth. 50 lightyears is considered the minimum safe distance for large mammals to survive). The milky way has collided with at least 3 other (tiny) galaxies, none of the collissions were (are) anywhere near us, as the tidal stresses would alter planetary orbits, and so on and so forth. All of this is ignoring the physical necessities for life to exist. If the fine structure constant, for instance, was 0.1% bigger or smaller, there would be no chemistry, and no humans. If the speed of light was ~5% bigger or smaller, there would be no atoms, as there would not be any stable electron orbitals, and so on.
Gravityloss 12y ago
I wish there were a lot more of missions like these. We should accept some failures as well. If the cost can be lowered, the increased risk can be offset by more tries. It's better for the science as well if the missions are more diverse and the lead times are shorter. I hope humanity grew up, so that failures would not produce so much backlash. Seems everybody feels so entitled in this age.
- CoolGuySteve 12y ago
  I'm sure they figured this out and decided against it, but I never understood why they often only send 1 device on missions like these. I understand launching things is very expensive, but you'd figure the R&D and risk associated with failure would cost much more.
  - Monotoko 12y ago
    Aye, most of the work is already done. I'm sure a second one could be launched at a fraction of the cost.
  - danielweber 12y ago
    It's hard to wow the governments with "we are going to do the same thing again, much cheaper." Even though it's the good way to get the most science bang for buck.
  - Gravityloss 12y ago
    It's not common, yes. Spirit and Opportunity come to mind. Mars Express and Venus express were based on similar hardware.
guscost 12y ago
This was a very interesting mission, and sticking the landing alone means that it was a success. Well done, let's hope some interesting data was collected as a bonus.
guelo 12y ago
Is that a grammatically correct contraction for "Our lander is asleep"?
- dang 12y ago
  Yes.
  - justsee 12y ago
    Hey dang - I noticed the comment below I made which stuck to the top for most of this thread's life dropped to the bottom at the time you commented here. What's the process for penalising posts in this situation? Is it just an individual decision where you've decided it distracts from a valuable discussion? I see I could have been a little less harsh with the damnning commentary (only to a point), but ultimately if we're all scientifically-minded then knowing that the internal targets were airbrushed for the public is a bit of a cerebral 'what?' I'd expect we're down with exploring on HN.
    - dang 12y ago
      This is the sort of thing the HN guidelines ask you to email us about: hn@ycombinator.com. https://news.ycombinator.com/newsguidelines.html https://news.ycombinator.com/newsguidelines.html
ForFreedom 12y ago
We shot that fridge from earth and guided it for 10 years and prior to launch we had it in planning for another 15 years or so to have a battery depletion on the second day? Why didnt they just use nuclear energy?

Our lander’s asleep

392 points by jonnyscholes 12y ago

valevk 12y ago

What kind of data did the lander gather, and will it be open to the public?

vixen99 12y ago
It had better be given that the public paid for it at a minimum cost of 1.4 billion Euros for the strictly European input.
- sz4kerto 12y ago
  It will be given to the public -- in contrast to 99% of scientific research results published by private companies like Elsevier making you pay $30 per article (or less, doesn't matter: you must pay to get the results of a research funded by you). Edit: most of it will be, not everything, as I've just found out.
  - vixen99 12y ago
    Completely agree. It is outrageous. I am researching a topic at the moment and expected to pay £20 for the privilege of viewing a paper (with work funded as you say, by the taxpayer) published in 1960. As to the project, the cost (open to correction by all means) was 1.4 billion. Downvote if you like; evidently this is my big mistake for not understanding that facts are apparently unwelcome hereabouts. If people assume that by mentioning this sum I am necessarily disapproving of the project then they are simply wrong and indeed had not one iota of evidence to suppose that. Now I know better - 'I must not mention the cost in case something thinks I am moaning about it'.
    - Anon84 12y ago
      Just let me know what you need. I'm happy to forward to you anything I can get through my university access. I'm sure others here are willing to do the same so we should have most things covered.
- dingaling 12y ago
  Much of the Rosetta data is under embargo, because the instruments were not paid for by ESA but private organisations like Max Planck Institute. Hence the paucity of hard data released to the public; the organisations have first dibs on the data to make their money back through publications and in attracting research funding. As an example: http://www.mps.mpg.de/1979387/MPS-Beteiligungen_an_Rosetta http://www.mps.mpg.de/1979387/MPS-Beteiligungen_an_Rosetta Basically, ESA provide the bus on which the science kit rides. As an EU tax-payer I've raged against this in the past but that's just the way it is. Source: direct question on this matter that I put to an ESA PR at a public lecture about Rosetta.
- danmaz74 12y ago
  Yes, it would have been much much better for us Europeans to use that money to subsidize our agriculture a bit more... /s
Maxious 12y ago
The data should appear on http://www.sciops.esa.int/index.php?project=PSA&page=rosetta http://www.sciops.esa.int/index.php?project=PSA&page=rosetta and http://pdssbn.astro.umd.edu/data_sb/missions/rosetta/index.shtml http://pdssbn.astro.umd.edu/data_sb/missions/rosetta/index.s... and http://nssdc.gsfc.nasa.gov/nmc/datasetSearch.do?spacecraft=Rosetta http://nssdc.gsfc.nasa.gov/nmc/datasetSearch.do?spacecraft=R... The lander data includes infrared imagery, x-ray spectroscopy results, electrical conductivity measurements, temperature readings (from harpoons), acoustic data, gas analysis and magnetometer data http://nssdc.gsfc.nasa.gov/nmc/experimentSearch.do?spacecraft=Philae http://nssdc.gsfc.nasa.gov/nmc/experimentSearch.do?spacecraf...
- valevk 12y ago
  Thanks for the references! Do you happen to know when the first results (verified interpretations of the data) are usually published after such experiments?

anvandare 12y ago

Anthropomorphizing machines somehow always manages to twang my emotional snares. http://xkcd.com/695/ http://xkcd.com/695/ Good night, little lander. Hope you dream of electric sheep.

Pyrodogg 12y ago
If you like that xkcd, this'll twang a few more heartstrings. Imposter by The Doubleclicks https://www.youtube.com/watch?v=pHU67s5tOSA https://www.youtube.com/watch?v=pHU67s5tOSA
codeonfire 12y ago
When did machines begin tweeting as themselves? I find it odd as there are usually lots of tweets that no person would make such as "scientists are sending commands to repair my body." or "soon technicians will install new parts into me."
- IndianAstronaut 12y ago
  Welcome to the world of PR.
- prawn 12y ago
  This is one way you take science to the masses. I think giving each Philae instrument its own Twitter account is a great idea.
  - StavrosK 12y ago
    I find it pretty deep in the uncanny valley.
    - prawn 12y ago
      I wonder if you are not the target audience?
DodgyEggplant 12y ago
http://www.youtube.com/watch?v=ayM68-4EioY#t=925 http://www.youtube.com/watch?v=ayM68-4EioY#t=925

ThePhysicist 12y ago

“Each night, when I go to sleep, I die. And the next morning, when I wake up, I am reborn.” - Mahatma Gandhi Let's hope it will wake up and be reborn. The chances for this seem not that bad, since the comet will heat up considerably as it approaches the sun, which will make it unnecessary to preheat the interior of Philae before starting to charge the batteries, while at the same time increasing the solar power reaching the panels (due to the sun being closer), so the lander might actually generate enough power to recharge the batteries and come alive again. Let's keep our fingers crossed.

raverbashing 12y ago
They also managed to rotate the lander so it gets more sunlight
- ThePhysicist 12y ago
  Yeah right, let's hope this helps as well! Of course there's the possibility that the panels will get more sunlight as the angle of the comet's rotation axis changes respective to the sun.
maaku 12y ago
That's one of the most scary quotes ever. Way to write a horror story in 2 sentences.
- blrgeek 12y ago
  If you've never thought about sleep that way, you should be scared! How do you know the person who woke up this morning is the same person who went to sleep last night?
  - bronson 12y ago
    How do you know the person who clicked the "Reply" button is the same person who wrote those words?
  - 12y ago

bitwize 12y ago

Do not go gentle into that good night, Philae. Rage, rage against the dying of the light.

shdon 12y ago
You made me look up that poem. I hold you responsible for the tears it brought.

stinos 12y ago

Everytime I read about tech like this I cant help but wonder What kind of mainboard does this run? What CPU? What temp spec? what OS does it run? What is the main laguage? Would it use open source code? Anyone has a clue or educated guess? edit thanks to all answers provided, exactly the info I was looking for! And very interesting as well.

acqq 12y ago
Regarding the power source, and why the mission depended on only solar energy: "Why was RTG (Radioisotope thermoelectric generator) not used in Rosetta mission?" https://news.ycombinator.com/item?id=8610585 https://news.ycombinator.com/item?id=8610585 Only US and Russia have the technology.
pjmlp 12y ago
Most likely Ada, C or C++ with very strict code guidelines, which even make C feel like Ada. Alongside real time OS like VxWorks, QNX, Aonix, .... There was a presentation at CppCon about Mars Rover. https://www.youtube.com/watch?v=3SdSKZFoUa8 https://www.youtube.com/watch?v=3SdSKZFoUa8
fjarlq 12y ago
Some details: http://space.stackexchange.com/questions/593/on-board-computer-data-handling-system-of-rosetta-details http://space.stackexchange.com/questions/593/on-board-comput... Note that the RTX2010 uses Forth: http://en.wikipedia.org/wiki/RTX2010 http://en.wikipedia.org/wiki/RTX2010
duckson 12y ago
I don't know about Philae/Rosetta's hardware in particular, but there are very specific requirements to hardware that's sent into space. I'm using the Mars Science Laboratory as an example here: The MSL uses twin PowerPC RAD750 boards. If one of them fails, the rover could use the other as a backup. After all, you can't go out to Mars to fix a firmware update gone wrong. :) The RAD750's are hardened against radiation in space, and can withstand extreme temperatures. They run at about 200Mhz, and cost around $200.000 a piece. [1] [2] It runs the realtime operating system VxWorks, which also happens to be what Apple uses for their Airport routers. :) [3] NASA uses C as their main language, with specific coding standards. [4] [1] http://en.wikipedia.org/wiki/Mars_Science_Laboratory#Rover http://en.wikipedia.org/wiki/Mars_Science_Laboratory#Rover [2] http://en.wikipedia.org/wiki/RAD750 http://en.wikipedia.org/wiki/RAD750 [3] http://www.extremetech.com/extreme/134041-inside-nasas-curiosity-its-an-apple-airport-extreme-with-wheels http://www.extremetech.com/extreme/134041-inside-nasas-curio... [4] http://lars-lab.jpl.nasa.gov/JPL_Coding_Standard_C.pdf http://lars-lab.jpl.nasa.gov/JPL_Coding_Standard_C.pdf

justsee 12y ago

As late as 12 November, the ESA's own FAQ [1] was stating that Philae's minimum mission target was one week of surface operation (powered entirely by primary batteries), with even more operational time powered by back-up batteries (themselves recharged by solar) - resulting in an expected surface operation period measured in months. They airbrushed the FAQ on 12 November to remove mention of the minimum one week mission target, and inserted among other things '2.5 days'. [2] A diff of the two versions would probably be interesting. Now with the lander mission prematurely ended an associated scientist is tweeting a very rosy summary [3]: "What a perfect ending. All the science completed, data received. Primary mission successful. Well done everybody." How can a week of carefully-planned scientific activities be 'completed' in only 2.5 days? It seems implausible. How did the primary and secondary batteries not power the lander for the calculated one week+ of operation? Why aren't they open about what clearly seems to be a major failure with the scientific mission? It seems a case of intense bureaucratic / political pressure to change targets after they aren't met, and the fact scientists are participating in this is pretty disappointing. [1] https://web.archive.org/web/20140805030451/http://www.esa.int/Our_Activities/Space_Science/Rosetta/Frequently_asked_questions https://web.archive.org/web/20140805030451/http://www.esa.in... [2] http://www.esa.int/Our_Activities/Space_Science/Rosetta/Frequently_asked_questions http://www.esa.int/Our_Activities/Space_Science/Rosetta/Freq... [3] https://twitter.com/rocketeddy/status/533421309553016832 https://twitter.com/rocketeddy/status/533421309553016832

acqq 12y ago
The targets have to change during the mission. The initial plan was even the another comet. It shouldn't matter. http://en.wikipedia.org/wiki/Rosetta_%28spacecraft%29 http://en.wikipedia.org/wiki/Rosetta_%28spacecraft%29 "Rosetta was set to be launched on 12 January 2003 to rendezvous with the comet 46P/Wirtanen in 2011. This plan was abandoned after a failure of the Ariane 5 carrier rocket during a communications satellite launch on 11 December 2002, grounding it until the cause of the failure could be determined." No reason to blindly stick to the initial target when you're doing something for the first time ever. It's not that you planned to drive from your home to the shopping mall and have to excuse to your other that you went drinking beer instead. You would probably complain that it's not an initial comet now too? The device landed on the darn comet! After travelling 6 billion km in 10 years. Managed to work a few days and send the data! First time ever! Powered only by the solar energy! (+) In the outside temperature of absolute zero. How many firsts do you need? https://www.youtube.com/watch?v=uEY58fiSK8E https://www.youtube.com/watch?v=uEY58fiSK8E Nothing built by humans was ever on the comet surface before. This thing even worked. +) Edit: Thanks to jdiez17 for pointing that the lander used a non-rechargeable battery on the comet surface. It was all the time planed to do the main work with that battery. The solar powered work wasn't the primary objective.

jordanthoms 12y ago

It appears to be largely political issues that prevented this mission from using a Radioisotope thermoelectric generator , which would have eliminated this particular problem since solar panels would not be required. [1] This is how the Curiosity rover is powered. If that is the case it's a massive shame - irrational fear of nuclear technology does a lot of damage. 1 - http://www.space4peace.org/ianus/npsm2.htm#2_3 http://www.space4peace.org/ianus/npsm2.htm#2_3

acqq 12y ago
The first (failed) mission to Mars was attempted as early as 1960 by the USSR, continuing with 1964, 1965 Mariner by the US. Rovers came after a lot of previous work done, including a lot of unsuccessful attempts. And the rover weights 900 kg, probably 40 kg of it is the nuclear power generator. Philae is only 100 kg and the first on the comet. It's certainly not "fear" of the nuclear technology in Europe that prevented something. See for example: http://en.m.wikipedia.org/wiki/Nuclear_power_in_France http://en.m.wikipedia.org/wiki/Nuclear_power_in_France It's that the engineering tradeoffs have to be considered.
- guscost 12y ago
  While it seems perhaps uncharacteristic of a space agency to make engineering decisions based on politics, if I had to guess I'd imagine that the team was well aware of the PR effect of the power supply chosen for their lander. I would also guess that the same issue was considered at NASA while planning the Mars Exploration Rover (solar) and Curiosity (RTG) missions. Are you claiming that this did not factor into their decision at all?
  - NeverEnough 12y ago
    that it wasn't a significant factor, at least
    - guscost 12y ago
      Fair enough. I don't know nearly enough about Europe or the ESA to volunteer an over/under on that.

tete 12y ago

I'm really curious about the results. This is the first time something like this has happened, but with the results, actually knowing a lot of variables, not even from the lander itself other missions will have something to base their work upon. The first programming languages (static, duck typed, ...), database systems, web frameworks, anonymization frameworks, ... all had a lot of things that were either far from perfect or are now considered stupidity. But when nobody did what you did, when you are a pioneer everyone following would be a fool not to look at your work. Also a nice example: Operating Systems. In the early days they were considered a waste of energy, time, resources. Why would you want to emulate computers on other computers (no, not visualization, but running multiple programs) or why would you use that valuable memory/storage space to have multiple programs on a machine at once? Those used to be actual questions. But that's a bit far fetched. The project was/is a real pioneering project and I have lots of respect for people investing all their lives (more than two decades in this case!) so passionately into landing on a comet. Not too long ago that was science fiction. The first message on the internet (arpanet) was meant to be "login", but it crashed after the o. I think those people got further, even though without doubt it didn't run as hoped for.

erre 12y ago

Rosetta wouldn't have some mirrors, or even reflective surfaces, would it? It could position itself to reflect sunlight onto Philae. I mean, I'm sure Rosetta has neither (in useful conditions), but there's a thought for next time :/

sylvinus 12y ago
This was asked in a French Q&A session with the ESA and they dismissed it as "science-fiction" :) http://www.lemonde.fr/sciences/article/2014/11/13/philae-peut-transmettre-des-informations-tant-qu-il-dispose-de-puissance_4523384_1650684.html http://www.lemonde.fr/sciences/article/2014/11/13/philae-peu...
- erre 12y ago
  Well, I meant it more as "hopeful pondering", but point taken :)
Ono-Sendai 12y ago
That would be possible in theory, a few problems though: You would need a flat surface to reflect light towards Philae, so the only appropriate surface would be the solar panels. The solar panels are not mirrors however, they would probably only reflect about 5%-10% of the sunlight towards Philae. This is even assuming the solar panels are sufficiently flat. Also the location of Philae is unknown (AFAIK), so there is the problem of where to aim the reflected light. Finally the relative direction from Rosetta would presumably change as the comet rotates, which means the solar panels or Rosetta as a whole would need to be continuously aimed at Philae, using propellant and/or other energy.
thyrsus 12y ago
Apollo retroreflectors. https://www.xkcd.com/1441/ https://www.xkcd.com/1441/

splitbrain 12y ago

I assume that Philae isn't meant to be powered directly by sunlight but has an intermediate battery? So wouldn't it make sense to simply wake him once this battery is full, do some experiment, send the data and go back to sleep until recharged again? Shouldn't that work even with low light conditions, just that the sleep phases would be much longer than planned? The article sounds like they aren't sure Philae will ever wake up again.

acqq 12y ago
The space is unbelievably cold. The lander is in the shade, meaning the temperature there is probably mostly at least around minus 60 degrees. The battery has much higher operating temperature.
- waps 12y ago
  It's actually unknown whether there's an atmosphere there. Temperature in space is very cold, sure, but if there are no gas collisions nothing carries the heat away (like, say, on Antarctica). So the lander would only really be cold where it touches the comet, and the comet actually gets quite hot at times. Wikipedia mentions that Haley's comet was 70 degrees celcius (above zero) last time it passed by Earth. Despite geostationary satellites operating in an environment that's nominally -265 or so degrees celcius, the problem they usually experience is overheating, not freezing. Blackbody radiation will eventually carry the heat away, but we're talking decades to get to -100 or so. For instance, a human body at rest generates about 150 watts of power, which would kill you in geostationary orbit without a cooling system. It would kill you because it wouldn't take long for your body temperature to rise to 52 degrees, at which point your cell metabolism abruptly stops (your mitochondria will stop generating energy). It would take longer than it takes you to choke though. Though nobody's ever tried for obvious reasons, you should be able to exit a space station and get back in with just a helmet that protects your mouth and nose and ears from decompression. You wouldn't freeze, you wouldn't explode. You'd overheat in 10-15 minutes or so. If you survive that, you'd die 2 weeks later from radiation poisoning. On the moon you need heating, because it actually has an atmosphere that would carry heat away. It is fun reminiscing about just how special our place in the universe is. Human bodies wouldn't be able to survive on planets 30% closer to the Sun, or about 15% farther away. We wouldn't be alive without a mostly oxygen atmosphere, because without the ozone layer, solar radiation would kill us. Without the earth magnetic field, solar radiation would kill us. Without the sun protecting us from interstellar radiation, we'd die. If our solar system was further to the outside of the milky way, we wouldn't survive the radiation, solar protection or not. If it was closer to the middle, we wouldn't survive. It's unknown whether it's a black hole at the center or something else, but it sure outputs a lot of radiation. Oh, and we're in the < 0.1% of the milky way that hasn't experienced a supernova explosion for about 3 billion years (a supernova explosion at 20 lightyears or less would kill all life on earth. 50 lightyears is considered the minimum safe distance for large mammals to survive). The milky way has collided with at least 3 other (tiny) galaxies, none of the collissions were (are) anywhere near us, as the tidal stresses would alter planetary orbits, and so on and so forth. All of this is ignoring the physical necessities for life to exist. If the fine structure constant, for instance, was 0.1% bigger or smaller, there would be no chemistry, and no humans. If the speed of light was ~5% bigger or smaller, there would be no atoms, as there would not be any stable electron orbitals, and so on.

Gravityloss 12y ago

I wish there were a lot more of missions like these. We should accept some failures as well. If the cost can be lowered, the increased risk can be offset by more tries. It's better for the science as well if the missions are more diverse and the lead times are shorter. I hope humanity grew up, so that failures would not produce so much backlash. Seems everybody feels so entitled in this age.

CoolGuySteve 12y ago
I'm sure they figured this out and decided against it, but I never understood why they often only send 1 device on missions like these. I understand launching things is very expensive, but you'd figure the R&D and risk associated with failure would cost much more.
- Monotoko 12y ago
  Aye, most of the work is already done. I'm sure a second one could be launched at a fraction of the cost.
- danielweber 12y ago
  It's hard to wow the governments with "we are going to do the same thing again, much cheaper." Even though it's the good way to get the most science bang for buck.
- Gravityloss 12y ago
  It's not common, yes. Spirit and Opportunity come to mind. Mars Express and Venus express were based on similar hardware.

guscost 12y ago

This was a very interesting mission, and sticking the landing alone means that it was a success. Well done, let's hope some interesting data was collected as a bonus.

guelo 12y ago

Is that a grammatically correct contraction for "Our lander is asleep"?

dang 12y ago
Yes.
- justsee 12y ago
  Hey dang - I noticed the comment below I made which stuck to the top for most of this thread's life dropped to the bottom at the time you commented here. What's the process for penalising posts in this situation? Is it just an individual decision where you've decided it distracts from a valuable discussion? I see I could have been a little less harsh with the damnning commentary (only to a point), but ultimately if we're all scientifically-minded then knowing that the internal targets were airbrushed for the public is a bit of a cerebral 'what?' I'd expect we're down with exploring on HN.
  - dang 12y ago
    This is the sort of thing the HN guidelines ask you to email us about: hn@ycombinator.com. https://news.ycombinator.com/newsguidelines.html https://news.ycombinator.com/newsguidelines.html

ForFreedom 12y ago

We shot that fridge from earth and guided it for 10 years and prior to launch we had it in planning for another 15 years or so to have a battery depletion on the second day? Why didnt they just use nuclear energy?