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Philae has landed

1165 points| talltofu | 11 years ago |bbc.com

Live coverage here http://news.yahoo.com/video/abc-news-plus-special-report-220000361.html

Thanks @brianpgordon - Check out this gif of the orbital maneuvers required for Rosetta to reach its destination: https://i.imgur.com/TUkKuhf.gif

Live twitter feed of ESA https://twitter.com/esaoperations

It looks like @Philae2014 made a fairly gentle touch down on #67P based on amount of landing gear damping #CometLanding

299 comments

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[+] kartikkumar|11 years ago|reply
Absolutely stunning feat of engineering. My bosses are on the drill team for Philae and were amongst the nervy faces being beamed all over the world. Great example of what European nations can do when politics don't get in the way. ExoMars [1] and Bepi-Colombo [2] are perfect examples of the inverse.

Look forward to the first pictures from the surface. I'm at the Division on Planetary Sciences (DPS) meeting [3] in Tucson at the moment, and there are already incredible results being presented based on data acquired by Rosetta. Stay tuned for a whole lot more!

[1] http://exploration.esa.int/mars/46048-programme-overview

[2] http://www.esa.int/Our_Activities/Space_Science/BepiColombo_...

[3] http://aas.org/meetings/dps46

[+] kartikkumar|11 years ago|reply
Just an update: the harpoons did fail, but the engineers were very concerned about marked fluctuations in the telemetry. There was a suggestion that the lander might actually be tumbling, but those fears seem to have been allayed by the fact that the oscillations seem to have stopped. The engineers will comb through the data over the coming hours, in anticipation of the next downlink, which should be around 4:30am CET (13th Nov). It seems like there might have been bit of a bounce, and the lander might have landed twice! So long as the downlink is available during the next pass, it seems like the lander has weathered the worst of the landing.

Science data has been downlinked, so fingers crossed we'll get some nice images from the surface pretty soon! There's a nice shot of the lander on the way down released already [3].

Sources:

[1] http://www.bbc.co.uk/news/science-environment-30031531

[2] Personal communication from ESOC, Darmstadt, Germany

[3] https://blog.flickr.net/en/2014/11/12/rosettas-philae-probe-...

[+] bane|11 years ago|reply
I agree, stunning stunning bit of science and engineering. Everybody involved in this should be beaming with joy.

Once again the light of reason continues to chase away humanity's ancestral boogiemen.

[+] return0|11 years ago|reply
Care to give a hint about what kind of results those are?
[+] kaeluka|11 years ago|reply
I have been following this mission for months now. I was completely obsessed. Didn't get much work done today, that's how excited I was. That must be how groupies feel like :)

Amazing landing, whether or not the screws are in: hitting the comet is already amazing!

[+] mathattack|11 years ago|reply
I have to say this is Science Awesomeness at it's best, and I'm bothered by the lack of media coverage. Perhaps if all of us posted and retweeted we could get some motion on this?
[+] innguest|11 years ago|reply
How can you people be so dishonest with yourselves and everyone else?

Look at the fallacious arguments you put forward:

- Nations have a long history of funding exploratory ventures. (appeal to tradition - doing something for a long time does not make it right to keep doing it)

- it creates jobs (unseen consequences - it destroys more needed jobs that would have been created or maintained had this money been used by those who earned it)

- there is a small chance that something practical could be discovered (citation needed; also, not a good enough reason to justify mass extortion)

- it satisfies a basic human need to know more (at what price? how much money is it fair to steal from the population in order to indulge the curiosity of those who largely can't be bothered to finish a book?)

- surely that's worth spending some money on? (no one is saying you can't spend your money on it. knock yourself out)

- but a world without curiosity would be pretty sad (appeal to emotion and consequences - this is coming from someone not curious enough to know how money works and why public works projects are the same as the broken window fallacy)

- Because it has huge benefits (citation needed)

- one could argue that the money that was funneled into NASA during the moon landings gave tax payers much more bang for their buck than all kinds of other research, social programs, bank bailouts, etc. (please go ahead and make that argument)

- These sorts of human achievement defining missions are really hundreds of thousands of hours of engineering dedicated to solving some of the hardest problems we can dream up. (Keynesian misattribution of value: "it takes a long time and a lot of effort so it has to be worth something!")

- You are way too short sighted (ad hominem)

- This opinion is short-sighted. (ad hominem)

- There may be zero practical attributable scientific or engineering benefits, though I am sure there will be plentiful. ("trust me, I know more than you do")

- However, such epic events are extremely inspiring! (appeal to emotion)

- This may be a single trigger that will send many curious young guys and girls towards STEM professions. (anything mya be a trigger to anything until proven to be the case or not; if we're looking for triggers to sent guys and girls to STEM we should survey the alternatives and pick the most cost effective one; this is an improvised excuse for carrying on with public works projects)

- I 'd dare you to specify what's more important where your money should be spent. (stolen money should not be spent in more or less important things, it should be returned to their rightful owner so they can choose what to do with what they've earned)

[+] throwit99|11 years ago|reply
At the risk of turning political, it's a great example of how our taxes are wasted. Playing with space toys shouldn't be funded with taxpayer money.

I'm sure I'll get downvoted to hell for this, but why should my money be funding this? Sorry, but it has no benefit whatsoever.

edit: Instead of downvoting a dissenting voice, why not argue your case - why should taxpayers fund space toys?

edit2: Well, looks like I'm banned from commenting. Good job dealing with those that don't agree with you...

[+] bd|11 years ago|reply
First images from Philae's ROLIS camera:

-----------------------

1) 3km above comet:

https://twitter.com/DLR_de/status/532587248555143169

2) Few seconds before landing:

https://twitter.com/nanotousch/status/532593372218023936

3) First surface image?

http://i.imgur.com/0XK8Ar4.jpg

4) Possibly a new image from the descent?

https://pbs.twimg.com/media/B2QySLrCUAAZbEL.jpg

Edit: no, here is the source (Rosetta's NavCam from yesterday):

http://www.esa.int/spaceinimages/Images/2014/11/NAVCAM_top_1...

-----------------------

Rosetta Lander Imaging System (ROLIS)

http://nssdc.gsfc.nasa.gov/nmc/experimentDisplay.do?id=PHILA...

[+] sktrdie|11 years ago|reply 

  More analysis of @Philae2014 telemetry 
  indicates harpoons did not fire as 1st thought
Ouch, seems like it didn't land? https://twitter.com/esaoperations/status/532575061543485440

edit - the landing is confirmed, however the harpoons did not fire: https://twitter.com/ESA_Rosetta/status/532579871202238464

[+] bd|11 years ago|reply
Emily Lakdawalla tweets from the control center:

Ulamec: signal kept coming and going "but we always got it back." Possibly indicates unstable, or tilted.

Ulamec confirms the harpoons did NOT fire. There is much they currently do not know.

Ulamec: a central rod was pushed into lander 4 cm by landing. Indicates soft rather than hard surface (rod would've pushed more into lander)

Just had a chat with Mark McCaughrean and I feel a bit calmer....

McCaughrean: @Philae2014 is down on the surface of the comet and it is transmitting signals. Science instruments are getting data.

Yes, McCaughrean confirmed this. RT @JPMajor: @elakdawalla So the ice screws on the lander's feet have at least dug in I assume?

https://twitter.com/elakdawalla/status/532578862086250497

------------------------------------------

And overview of the German DLR stream's briefing (via reddit live stream):

Good news:

--- Touchdown, all the signals that trigger on touchdown worked.

--- Still communication, which means the lander did not tilt or topple.

Bad news:

--- ADS thruster did not fire, that is the issue was already known beforehand.

--- The anchors did not fire, this confusion was due to the rewind motors for the anchors going into action, but the harpoon wasn't actually fired.

--- Team doesn't know if it rebounded or not / if it's on the surface. Thus they don't dare issuing a re-firing signal for the harpoons, because they don't know in what position the lander is. Current Situation:

--- The arm that damped the landing force only moved very little, which indicates a very soft surface. Which might mean if it rebound the rebound was very soft as well and in this case might settle down again.

--- On board computer is waiting for new commands.

--- There will be more telemetry in 30 minutes, but contact lost in 120 minutes, so the final verdict could be known only tomorrow.

http://www.reddit.com/live/tw0cnch7nxjx/

[+] masklinn|11 years ago|reply
It did land, here's the next tweet:

> It looks like @Philae2014 made a fairly gentle touch down on #67P based on amount of landing gear damping #CometLanding

but the harpoons may have failed to fire.

[+] bsaul|11 years ago|reply
Anyone knows where i could find some info about the software stack this kind of probes are being built with ? Languages, programming methods, patching methods,os, runtime, etc.

I'm really curious to know how different it is from the web or enterprise development worlds.

[+] adamfeldman|11 years ago|reply
Like other embedded systems, spacecraft computers use real-time operating systems (RTOS) and languages:

* The Rosetta probe ultimately runs SCL (Spacecraft Command Language) [1], a COTS spacecraft programming language developed for sale to the military [2]; SCL is based on the syntax of Ada 83, which has a long legacy in spaceflight and other real-time applications (e.g. Boeing 777) [3]. However, what are known as Flight Control Procedures (uploaded commands), are written using another language and transformed and compiled into SCL in a two-step process that involves XSLT [1]. On-board Control Procedures, which are procedures the probe decides on its own to run, and handle tasks such as receiving FCPs and sending back telemetry, are written in SCL [1].

* The Mars rover Curiosity is programmed in C and uses the VxWorks RTOS [4], which is very much like many commercial embedded systems. It has about 2.5 million lines of code, much of it autogenerated. Curiosity's predecessors, Spirit and Opportunity, used the same software stack, as did their predecessor, Sojourner [8].

* The Voyager probe, which has now left the solar system and entered interstellar space, uses "...interrupt driven computer[s], similar to processors used in general purpose computers with a few special instructions for increased efficiency. The programming is a form of assembly language." [5]

* The Space Shuttle was programmed in a custom language called HAL/S (High-order Assembly Language/Shuttle) [6], as was the Jupiter probe Galileo [7]. The language is descended from PL/I and its compiler is written in a subset of PL/I called XPL.

[1]: http://www.rheagroup.com/wp-content/uploads/2014/01/SpaceOps...

[2]: https://www.sra.com/scl/

[3]: https://en.wikipedia.org/wiki/Ada_(programming_language)

[4]: http://programmers.stackexchange.com/a/159638

[5]: http://voyager.jpl.nasa.gov/faq.html

[6]: https://en.wikipedia.org/wiki/HAL/S

[7]: https://en.wikipedia.org/wiki/Galileo_(spacecraft)

[8]: http://programmers.stackexchange.com/a/159687

[+] sktrdie|11 years ago|reply
Most likely they have headless web browsers running on both the main spacecraft (probably chromium) and the Philae lander. Web sockets enables the lander to communicate to the spacecraft which then sends its signals down to earth using regular HTTP (you don't want to keep an interstellar HTTP connection open). All of it is of course written in JavaScript, more specifically vanilla-JavaScript - which frankly I find weird given that I'd hope they would use a framework such as socket.io - bad engineering if you ask me. The lander obviously uses latest Node.js and npm to update some of its modules which are again sent across the wire using interstellar HTTP.
[+] tim333|11 years ago|reply
There's some discussion here, written by Attila Baksa who according to his linkedin is "Designer and developer of flight software of On-board Computer of the Rosetta Lander of ESA, which was successfully launched in 2003 and arrived to comet P67 in 2014."

eg: "The on-board software of the central computer of the Philae Lander consists of a real-time operating system and 8 application tasks. All these software modules are specially developed by our team for the Harris RTX2010RH microprocessor. The co-ordination of the scientific program and the overall control of the algorithms used by the application tasks are done by the MSO modelling language."

http://www.hiradastechnika.hu/data/upload/file/2004/2004_12/...

Also the "scheduling system, called the Rosetta SGS Scheduling Component" is discussed here:

https://ai.jpl.nasa.gov/public/papers/chien_iwpss2013_schedu...

which uses a framework called APSEN written by NASA:

http://aspen.jpl.nasa.gov/

which takes code like this:

Activity prevalve removal {

duration = 15

slot subsystem

after prevalve prep with (subsystem == this.subsystem)

before prevalve replace with (subsystem == this.subsystem)

Reservation hydraulic lift usage {

resource = hydraulic lift; usage = 1;

duration = 5;

requires state prevalve-purged TRUE

requires state prevalve-illuminated TRUE

 to control the thing

http://metahack.org/isairas97-aspen.pdf

[+] kevinmchugh|11 years ago|reply
This article is a classic, coming up on 20 years old, specifically about how differently the shuttle software team was from the dotcoms. http://www.fastcompany.com/28121/they-write-right-stuff

No idea how relevant it is today, or any differences between the shuttle team and whoever's building/built the software for this lander, but it's definitely worth a read.

[+] notfunk|11 years ago|reply
While I'm not sure what this exact probe is built upon, some popular choices for mission critical applications I've seen in the past are:

* VxWorks for real time operating system (proprietary)

* Ada/C++ for programming language.

[+] the_rosentotter|11 years ago|reply
Coverage of this has been very confusing.

The ESA live feed at most times show people in some kind of control room staring at screens. There is no apparent way to see any highlights, unless I want to try scrolling back and forth through the hour-long video stream.

At any given time, various forum threads seem to have more information than the ESA site, which seems to communicate mostly through either lighthearted tweets, one-line headlines, or general background articles.

All I want is a simple timeline of events, constantly updated with latest news and images. Instead we have forum threads where you have to dig through comments to find out what is the newest info.

[+] k-mcgrady|11 years ago|reply
>> "All I want is a simple timeline of events, constantly updated with latest news and images"

OT but it's kind of amazing that this is actually a simple request these days.

[+] ajuc|11 years ago|reply
Wow, I listen to the solutions they invented to hibernate the probe safely - to save on the electricity they had to hibernate it, but then it could have change orientation relative to sun, and wouldn't have enough energy to wake up.

So they disabled the orientation system to save energy, but first they made the probe rotate quickly to stabilise it like a gyroscope.

That's stuff from sci-fi books / Mc Gyver movie :)

[+] k-mcgrady|11 years ago|reply
Amazing job! This might be a silly question but are their any ideas as to the actual real world benefits we could see from this? The director-general of the ESA said "This is a big step for human civilisation" so I presume there is some idea of what they expect to gain from this mission?

Edit: Thanks for all the replies! I'm at work now but will take a look at them this evening.

[+] valarauca1|11 years ago|reply
The actual real world benefits of Space Flight are strange. For example the Apollo program didn't bring back DeathCrystals from the moon, that allowed us to crush the Soviets in a glorious patriot war (obviously sarcasm).

Instead it gave us seemly random things, that we were looking for, but are beneficial nonetheless and some which may not come out right away.

The Apollo Mission gave us

ASICs, Cordless Tools, CAT scan, Ear Thermometer, Smoke Detector, Shoe insoles, carbon based water filters, satellite television (boardcasted, not passive reflected), Scratch resistant lenses.

These things aren't why we went to the moon. Inventing them kinda just happened to see the program though. Space travel challenges the status quo of technology. Its really REALLY hard. So when ever we (humans) do it, we face new problems, and our solutions sometimes have effects for those on earth.

[+] brianpgordon|11 years ago|reply
Check out this gif of the orbital maneuvers required for Rosetta to reach its destination:

https://i.imgur.com/TUkKuhf.gif

This probably won't be very impressive in a few hundred years, but for now it's a remarkable engineering achievement.

[+] ffk|11 years ago|reply
There are several benefits gained, both scientifically and politically.

Scientific:

* Comets may show us early composition of our solar system since they change less than planets. This may help answer questions related to where water came or where DNA/RNA molecules came from.

* Lessons learned here will directly contribute to the success of future missions on both mars and the moon

* Solar cell technology was directly advanced, helping push forward solar energy

Political & Social:

* Brings governments closer together These types of missions require a great amount of cooperation and help stabilize and improve the international political landscape. Around 20 countries cooperated in this mission.

* Inspire more people to enter science, math and engineering

* Increase collaboration of universities and industry, helping close the gap between theoretical and applied science.

[edited to fix formatting]

[+] sophacles|11 years ago|reply
One thing the other (very good) replies miss: Never underestimate the power of 'gee whiz' technology has on children. This is cool, exciting engineering. Even if the scientific results are "boring", that is to say we don't get any unexpected data, the act of pushing the boundaries of what humans have been able to do is inspirational. There are kids who will learn about this in school the next few days, and see it on the news, and hear grown ups talking about how neat it is, and decide "I want to be an engineer", or "I want to be a scientist". It doesn't take many of them making this decision to have a big, long term impact (which provides a great societal ROI on the mission).
[+] Killah911|11 years ago|reply
It is just me or has the story evolved into something a bit less jubilant in the course of the last two hours. It's an amazing feat, but this stuff is always a huge gamble.

As someone's who's worked on a few spacecraft project I feel really bad for the team(s) (recently worked on one which didn't go so well, years of work down the tube). Even if it didn't go perfectly I hope they're commended for the work they've done so far & the landing they achieved.

[+] neiled|11 years ago|reply
Seeing their faces on the live feed when it landed was amazing. It must be so exciting.
[+] anExcitedBeast|11 years ago|reply
Science is amazing. I'm glad to be living in a period where I get to be around for stuff like this.
[+] adregan|11 years ago|reply
Hope this isn't a dumb question, but how does Philae stay put? If the gravity strong enough to keep it on the surface? Also, as the comet nears the sun and parts of the comet start flying off, is there a threat of Philae getting swept along with it?
[+] forgotpasswd3x|11 years ago|reply
The robot deployed harpoons to fasten itself to the 2.5-mile-wide ball of ice and dust.
[+] JoeAltmaier|11 years ago|reply
Harpoon, ice screw. Retro-rockets failed to deploy.
[+] owenmarshall|11 years ago|reply
> Also, as the comet nears the sun and parts of the comet start flying off, is there a threat of Philae getting swept along with it?

To add to what everyone else mentioned: Philae's science mission is slated to last for 2.5 days - the batteries have ~65 hours of charge, that's it. The hope is that they may be able to charge it and keep gathering data afterwards.

So it's not going to last nearly that long.

[+] 4ad|11 years ago|reply
Gravity is very weak, it harpooned itself into the surface. The comet doesn't come very close to the sun, only around 1.2AU or so.
[+] FlyingSnake|11 years ago|reply
This is an incredible day for science and Humanity. ESA, CNSA, ISRO, SpaceX etc have done a great job so far to carry forward the legacy of NASA and ROSCOSMOS to new levels.

Still can't believe ESA planned and landed a robot on a comet. Bravo!

[+] jmccreery|11 years ago|reply
No announcement yet, but just now in the ESA webcast of the control room everyone stopped, gathered around a guy that I assume is the team lead, and are now going home. I have a bad feeling about this.
[+] jnem|11 years ago|reply
Total non-sequitor but...I'm surprised no one else has yet made the observation that Philae Lander put together is philaender, or philander. Juvenile post of the day award anybody?
[+] rabino|11 years ago|reply
we just landed a friggin' robot into a friggin' commet

mind blowing

[+] ommunist|11 years ago|reply
This is huge. In both technical and political ways. And bringing all the details into live online event is twice as huge. I just watched the guy reporting the unsuccessful initial anchoring of the probe, and I felt so happy that I could see this. Incredible. By the way the lander software runs on Harris RTX2010 processors -- the US contribution.
[+] india_congrats|11 years ago|reply
Congratulations Europe. But why don't we hear people saying that the EU should focus on their poverty first and would be better off putting this money into getting the Greece, Spain, and Italy economies in order?