
Our lander’s asleep - jonnyscholes
http://blogs.esa.int/rosetta/2014/11/15/our-landers-asleep/
======
jordanthoms
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
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
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?

~~~
this_user
It seems highly unlikely that any scientists would make subpar choices that
may compromise a long-term project on the off chance that it might cause some
political discomfort. The latter isn't even particularly likely since there is
a large difference between nuclear power as an energy source on Earth and
nuclear technology for scientific use in space. In addition most of the public
doesn't even know or is interested in the technical details of a mission like
this. Therefore it is extremely unlikely that using RTG technology would have
caused any kind of political problems which makes avoiding said technology on
political grounds simply nonsensical when it has the potential to compromise
the overall mission.

~~~
guscost
I think you are 1) overestimating the amount of independence that a typical
space agency project actually enjoys and 2) underestimating both the amount
and variety of PR that a high-profile space mission like this one generates.

------
ThePhysicist
“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.

~~~
maaku
That's one of the most scary quotes ever. Way to write a horror story in 2
sentences.

~~~
blrgeek
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
How do you know the person who clicked the "Reply" button is the same person
who wrote those words?

------
anvandare
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.

~~~
codeonfire
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."

~~~
prawn
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
I find it pretty deep in the uncanny valley.

~~~
prawn
I wonder if you are not the target audience?

------
tete
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.

------
stinos
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.

~~~
duckson
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-
curio...](http://www.extremetech.com/extreme/134041-inside-nasas-curiosity-
its-an-apple-airport-extreme-with-wheels) [4] [http://lars-
lab.jpl.nasa.gov/JPL_Coding_Standard_C.pdf](http://lars-
lab.jpl.nasa.gov/JPL_Coding_Standard_C.pdf)

~~~
stinos
_If one of them fails, the rover could use the other as a backup_

Any idea how that works practically? I mean, there are two boards and one set
of peripherals. Is there like an external controller which constantly checks
if board A is doing fine, and if not, somehow reroutes all peripheral
communication to board B?

~~~
avar
The NASA website seems to imply that it's done manually:
[http://mars.jpl.nasa.gov/msl/mission/rover/brains/](http://mars.jpl.nasa.gov/msl/mission/rover/brains/)

Presumably there's some basic functions in the radio stack they use where they
can trigger operations like shutdown, startup, reboot, switch boards etc.

~~~
gsnedders
NASA normally has pretty low-level stuff. To the point of being able to do
full firmware updates — though obviously that's something they don't want to
risk ordinarily.

------
Gravityloss
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
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.

~~~
danielweber
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.

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

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

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

~~~
vixen99
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
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
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
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.

------
splitbrain
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
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
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.

~~~
SCHiM
> "It is fun reminiscing about just how special our place in the universe
> is..."

I think you have it slightly backwards there. Life on earth, and us
specifically, don't look the way we do because of chance. The reason we only
operate in this specific environment is because we were shaped by our
environments. Who knows in what environments life can exist. If you think of
life as some sort of self-organizing system it's not unthinkable that 'life'
could be possible in places that seem extremely inhospitable to us. Inside a
star for example.

~~~
acqq
In order to have "life" in the sense that can be interesting to us (that
means, not the "life" in the sense of something that is organized inside of a
some star which is unreachable by us) the properties of chemical elements can
be studied and apparently the properties of carbon are such that it is the
most probable element for organic chemistry. There are possible alternatives,
like silicon, but every alternative is less probable and less efficient that
carbon:

[http://en.wikipedia.org/wiki/Hypothetical_types_of_biochemis...](http://en.wikipedia.org/wiki/Hypothetical_types_of_biochemistry)

"Sagan used the term "carbon chauvinism" for such an assumption. Carl Sagan
regarded silicon and germanium as conceivable alternatives to carbon; but, on
the other hand, he noted that carbon does seem more chemically versatile and
is more abundant in the cosmos."

------
erre
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
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-
peu...](http://www.lemonde.fr/sciences/article/2014/11/13/philae-peut-
transmettre-des-informations-tant-qu-il-dispose-de-
puissance_4523384_1650684.html)

~~~
erre
Well, I meant it more as "hopeful pondering", but point taken :)

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

~~~
dang
Yes.

~~~
justsee
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
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
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?

------
justsee
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.in...](https://web.archive.org/web/20140805030451/http://www.esa.int/Our_Activities/Space_Science/Rosetta/Frequently_asked_questions)

[2]
[http://www.esa.int/Our_Activities/Space_Science/Rosetta/Freq...](http://www.esa.int/Our_Activities/Space_Science/Rosetta/Frequently_asked_questions)

[3]
[https://twitter.com/rocketeddy/status/533421309553016832](https://twitter.com/rocketeddy/status/533421309553016832)

~~~
acqq
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.

~~~
justsee
I'm just raising the kind of precise, detail-oriented questions that typically
emanate from this community.

Your response relies on an appeal to emotion rather than logic, and doesn't
seem particularly interested in engaging with the substance of the questions
raised?

~~~
acqq
The logic is: to get something at least approximately close to your goals done
_for the first time ever_ , you have to adjust your targets as you go. Every
other strategy simply doesn't work. You are welcome to just stick to your
initial goals in your endeavours. Write now absolutely exactly what you plan
to do for the first time. Than please report in some time and stick to
describing your failures. Observe how motivated for more you'll be.

And to paraphrase Louis, since when the 25-years lasting mission that you've
learnt it existed only recently owns you exactly seven days of function on the
darn comet?

To be more serious: of course the scientists will learn a lot even from every
thing that went wrong. That's exactly how science works. It still doesn't mean
that the public attention should concentrate on that now. See also my comment
response to the "mistake" claim.

~~~
johnchristopher
Of course you adjust your targets. But it doesn't imply you must rewrite your
expectations to fit with reality after the facts as if those expectations
never fluctuated. You actually lose data points by doing so.

~~~
acqq
Data points? The poster justsee actually complains about the FAQ page which
didn't even have to be precise in the first place and doesn't have to be now.
It's a web site directed to the uninformed public. Honestly, who do you expect
to use the FAQ page for anything serious?

Among other questions on that page are

"Why is it so important to study comets?"

"What is the difference between asteroids and comets?"

You don't bother public with engineering stuff like "we have 1000 Wh power
budget from the primary batteries, which will last depending on what happens
when, and the different devices have different energy needs and we aren't
actually sure what can happen but we prepare for as much as possible with the
hope of at least something giving us some good results." They just switch off.
We at least know where justsee switched off in being interested in the
details: the expression "during a week" he understood as somebody promised him
"exactly at least a week of entertaining news from the lander."

~~~
johnchristopher
> It's a web site directed to the uninformed public.

The `uninformed public` deserves to be better considered, thank you.

It's not about the quality of explanation or the depth of the technical
details in the FAQ but about the way it gives the feeling facts are being
rewritten to fit reality (if there are no mention on the page it is being
edited to accommodate for mission updates then it's completely understandable
people would frown over number shuffling).

Did you count the words on that FAQ ? Any `uninformed` person who would read
that FAQ would have questions about why the wording change over time.

Because it's a FAQ, not a live update.

> Honestly, who do you expect to use the FAQ page for anything serious?

Really ?

~~~
skywhopper
The FAQ _is_ rewritten as the facts change. They wanted a week, but the
landing didn't go well, so they figured out they could get 2.5 days, and they
changed the FAQ. It's not complicated. It's not a conspiracy. No one is being
cheated.

~~~
johnchristopher
Sigh...

> [..] if there are no mention on the page it is being edited to accommodate
> for mission updates then it's completely understandable people would frown
> over number shuffling [..]

Did I say I feel cheated ? No. Did I say there was a conspiracy ? No.

The web page has all the qualities of a static web page (no `live update`, no
`last modified` label, etc.) and it's on the ESA website which gives it some
kind of an official vibe. Yet, they are updating it to reflect mission
objective changes (which is totally fine as far as I am concerned, by the way)
which lead to confusion and questions such as "Did they just changed their
stated goals to accommodate for the fact Philae is going to operate for a
short time than planned or expected ?". Add to that some Internet tweets about
how "it smoothly perfectly gone well and all the data we wanted are there" and
someone goes back to the FAQ and spot changes (1 week turn into 2.5 days).

Allow me to take you for an idiot as well: _It 's not complicated._ to
understand that web page is a bit misleading. It doesn't relay the information
that the mission parameters and objectives changed (and of course I know they
changed, were likeley to, etc.). If you go back to that document in 20 years
you'd have no idea there was some problems with the landing.

