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Philae has landed

bbc.com

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Re: Philae has landed

#51

Post by gt565k »

forgotpasswd3x wrote: post #25
adregan wrote: post #21

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?

The robot deployed harpoons to fasten itself to the 2.5-mile-wide ball of ice and dust.

the harpoons failed to anchor to the surface, according to mission control, which was just announced on the live coverage. It appears they will try to reshoot the harpoons at some point if possible.

Re: Philae has landed

#52

Post by bsaul »

adamfeldman wrote: post #36
bsaul wrote: post #17

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.

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 Fl…

Very interesting. I didn't think C would be used that much (except for the core of the os of course). I somehow thought of either a specialized language with strong guarantees (such as ADA), or a high level language for IA-like feature.

Which makes me wonder, since this is HN after all, if Rust wouldn't be an ideal candidate for coding this kind of layer in the future. Maybe a compiler targeting VxWorks is in progress somewhere.. ? :))

Re: Philae has landed

#53

Post by kartikkumar »

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

Re: Philae has landed

#54

Post by [deleted] »

india_congrats wrote: post #44

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?

[deleted]

Re: Philae has landed

#55

Post by sktrdie »

bsaul wrote: post #17

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.

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.

Re: Philae has landed

#56

Post by a-priori »

forgotpasswd3x wrote: post #25
adregan wrote: post #21

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?

The robot deployed harpoons to fasten itself to the 2.5-mile-wide ball of ice and dust.

I love how simple and low-tech this solution is. People have been using anchored ropes and cables of various kinds to fasten things together for millennia. People have been using harpoons at sea for whaling for centuries.

Re: Philae has landed

#57

Post by notfunk »

sktrdie wrote: post #55
bsaul wrote: post #17

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.

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 we…

This is the best thing I've read all day.

Re: Philae has landed

#58

Post by sktrdie » 

  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

Re: Philae has landed

#59

Post by grey-area »

k-mcgrady wrote: post #45
avz wrote: post #29

Earlier quoted context omitted.

Improved understanding of our solar system, its history and our place in the universe is a real benefit that soon will be available for anyone. Comets are generally very old, so can enable us to learn a lot about solar system's history. Achieving engineering capabilities required to land on comets is a step forward for human civilization. I consider the above to be actual real world benefits. If they are not, I'm not…

Thanks. I would definitely consider the second point a real world benefit but if we are going to spend over $1bn to learn about the solar system's history I take it we are hoping to discover something that actually has benefits to humanity (e.g. when the money could have had more immediate impacts treating disease or helping the poor etc.). Don't get me wrong I'm all for these kinds of missions I just thought that to…

If you want to talk about spending priorities, how about the folly of the Iraq war, trident, etc. those cost huge amounts more than this mission? Not everyone has the same priorities as you.

Thank goodness at least some of our money is spent on things which might benefit humanity in the long term, like discovering how the solar system was formed or whether life was formed on earth or elsewhere.

Re: Philae has landed

#60

Post by kej »

kevinmchugh wrote: post #40
bsaul wrote: post #17

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.

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.

There was a nice bit about the shuttle's computer systems in the Challenger appendix to Surely You're Joking, Mr. Feynman, too. As I recall, it was the only part of the shuttle process that Feynman thought was engineered correctly.
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