Rosetta's comet mission discussion thread

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Discussion Overview

The discussion revolves around the Rosetta mission, specifically focusing on the landing of the Philae lander on comet 67P/Churyumov-Gerasimenko. Participants explore various aspects of the mission, including the selection of landing sites, the challenges of landing on a low-gravity surface, and the anticipated scientific outcomes of the mission.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Experimental/applied

Main Points Raised

  • Some participants discuss the details of the Rosetta mission, including its objectives and the technology involved in landing on a comet.
  • There is interest in the criteria used for selecting the landing sites, with some participants expressing curiosity about the specific factors considered beyond surface level.
  • Participants share links to resources detailing the pros and cons of the five potential landing sites, with some expressing preferences for specific sites based on their features.
  • Concerns are raised regarding the landing challenges due to the comet's low gravity and the need for the lander to secure itself effectively upon landing.
  • Some participants note the excitement surrounding the mission, highlighting its significance as a first attempt to land on a comet and the potential for new scientific insights.
  • There is mention of the failure of a critical thruster, leading to discussions about alternative anchoring methods that may be necessary for a successful landing.
  • Live updates and social media interactions related to the mission are shared, indicating a high level of engagement and anticipation among participants.

Areas of Agreement / Disagreement

Participants express a mix of excitement and concern regarding the landing, with some agreeing on the challenges posed by the comet's surface while others speculate on the implications of the thruster failure. Overall, multiple competing views and uncertainties remain regarding the landing process and its outcomes.

Contextual Notes

There are unresolved questions about the nature of the comet's surface and the effectiveness of different anchoring methods. The discussion reflects a range of assumptions about the landing site's characteristics and the mission's technological capabilities.

Who May Find This Useful

Individuals interested in space exploration, cometary science, and the technical challenges of landing on low-gravity celestial bodies may find this discussion engaging and informative.

  • #31
Dotini said:
On Sony Playstation 3, you can load GranTurismo 6 and drive a lunar rover.
I just want to fly a predator drone... landers and rovers are just too "20th century" for me.
 
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  • #32
Didn't die for me. It landed and "phoned Home". Whew! What a day!
 
  • #33
Congratulations! Well done for humanity!
 
  • #34
jerromyjon said:
Are the harpoons temporary until the legs drill?

What I think now is that all they have to anchor with is the two harpoons they have been talking about.

I don't have a clear picture of the mechanism. Also I heard a disconcerting bit of news announced from the Lander control room at Köln.

They had an unexpectedly soft landing, which seems good. But when they tried to fire the harpoons, either they did not fire, or they fired but did not take hold. The speaker said they were now studying the situation and considering whether to try again.

Does anybody have a diagram of the anchor mechanisms?

EDIT: I followed a link that Greg gave and found this:
https://twitter.com/hashtag/Rosetta?src=tren
If that link works it is a diagram that indicates that the screws in the footpads start drilling in as soon as there is contact.
Also there is a thruster on the top to give it a temporary downwards push.
And the two harpoons are under the belly of the thing. there seems to have been a problem with the harpoons. I have not heard anything about the drills or screws in the footpads, whether they were successful or not.

Do very much hope the lander gets a firm grip.

Looking forward to the chemistry analysis!
 
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  • #35
mfb said:
...
Edit: "Hollywood is good, but Rosetta is better" - Livestream a minute ago.

: ^D
Yes, I heard that on Livestream too. Was it the Swiss guy? ...wood good, ...etta bettah
sums it up deftly and succinctly.
 
  • #36
marcus said:
What I think now is that all they have to anchor with is the two harpoons they have been talking about.

I don't have a clear picture of the mechanism. Also I heard a disconcerting bit of news announced from the Lander control room at Köln.

They had an unexpectedly soft landing, which seems good. But when they tried to fire the harpoons, either they did not fire, or they fired but did not take hold. The speaker said they were now studying the situation and considering whether to try again.

Does anybody have a diagram of the anchor mechanisms?

Have a look at this : http://www.esmats.eu/esmatspapers/pastpapers/pdfs/2003/thiel.pdf
 
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  • #38
Does anyone know what are we going to see next? All I see now is people working at some computer lab and talking.
 
  • #39
Also check out these videos about the orbital maneuvers performed during the mission.





Hope I could perform any of these in KSP!
 
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Likes   Reactions: Greg Bernhardt
  • #41
Greg Bernhardt said:
Yashbhatt those videos really put into perspective how bonkers awesome this achievement is!

Ya. I was like staring with open mouth when I saw so many gravity assists and the the staggering complexity of maneuvers. But I did not understand why they performed a maneuver to get out of the original orbit plane and then back and so.
 
  • #43
  • #44
I was up until 4 am this morning, catching up, and watching videos.
I'm having technical difficulties embedding my favorite video I saw, so you'll have to just Google:
"Demonstrating Rosetta’s Philae lander on the Space Station"

It's on youtube.
 
  • #45
OmCheeto said:
I was up until 4 am this morning, catching up, and watching videos.
I'm having technical difficulties embedding my favorite video I saw, so you'll have to just Google:
"Demonstrating Rosetta’s Philae lander on the Space Station"

It's on youtube.

Talking about this one ?

 
  • #46
Yashbhatt said:
Talking about this one ?


Yes!

Thank you.
 
  • #47
See this everyone : Slooh is now showing the comet on which Rosetta landed. Live!

http://live.slooh.com/stadium/live/rosetta-harpoons-comet-67p-churyumov-gerasimenko

The small animated movie they have created is very cute.
 
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  • #48
links to some side information:
http://en.wikipedia.org/wiki/Philae_( spacecraft )
http://nssdc.gsfc.nasa.gov/nmc/ spacecraft Display.do?id=PHILAE
My rough guess is that the gravity where she is is about 1 mm per second per second. or about 1/10000 of a gee.
the mass of the lander is about 220 pounds, so the weight force would be about 0.02 pounds.
I could be off by quite a bit, can someone help with more accurate estimate of the comet's mass and surface gravity at the landing site?
EDIT: A Reuters article gave the estimated gravity as 1/100,000 of Earth gee. That sounds more in line with the estimated escape velocity of 1 meter/second. If that's close to right then the Lander weight is more like 0.002 pounds. 0.03 ounce. Sorry, I'm boggled. Maybe Reuter's and I are mistaken, but if we're right how can the lander not be blown away by sublimation as the surface warms?
 
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  • #49
marcus said:
links to some side information:
http://en.wikipedia.org/wiki/Philae_( spacecraft )
http://nssdc.gsfc.nasa.gov/nmc/ spacecraft Display.do?id=PHILAE
My rough guess is that the gravity where she is is about 1 mm per second per second. or about 1/10000 of a gee.
the mass of the lander is about 220 pounds, so the weight force would be about 0.02 pounds.
I could be off by quite a bit, can someone help with more accurate estimate of the comet's mass and surface gravity at the landing site?

This might be helpful. http://en.wikipedia.org/wiki/Philae_( spacecraft )
 
  • #51
marcus said:
links to some side information:
http://en.wikipedia.org/wiki/Philae_( spacecraft )
http://nssdc.gsfc.nasa.gov/nmc/ spacecraft Display.do?id=PHILAE
My rough guess is that the gravity where she is is about 1 mm per second per second. or about 1/10000 of a gee.
the mass of the lander is about 220 pounds, so the weight force would be about 0.02 pounds.
I could be off by quite a bit, can someone help with more accurate estimate of the comet's mass and surface gravity at the landing site?
Marcus, alas, gravity at the surface is equal to 0 (zero).
Chance only: enable the jet to fillet, fillet to flatten the surface, drill, drill two or three holes and drive there are two or three garpupa. All. The engine can be turned off.
 
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  • #52
There was some engineer on Slooh who said that even though of the harpoons have failed, the comet will remain on the surface.
 
  • #54
EU2AA said:
Marcus, alas, gravity at the surface is equal to 0 (zero).
no, the comet has mass, its gravity is non-zero, its just very small
 
  • #55
Yashbhatt said:
There was some engineer on Slooh who said that even though of the harpoons have failed, the comet will remain on the surface.
Yes, the comet is not going anywhere. But we are talking about Philae ...
 
  • #57
  • #58
Yeshe has a chance

It is possible that the engine is still running Philae?
It is possible that at least one harpoon can be recharged.

Then you need to download a new program at Philae:

- Landing soveshat harpoon forward as whaling boat;

- Aim your harpoon AML large stone such BLD;

- Shoot harpoon before touching the surface.
 
  • #59
davenn said:
no, the comet has mass, its gravity is non-zero, its just very small
MIB!

Frank also points out that humans must learn to understand the notion of scope in the universe; i.e. a very important and grand thing can be very small.

Ok. This might be a bit of a stretch in my "movies can inspire people to think" mindset.

But, um, I'm going to take a nap now.
 
  • #60
Given that it apparently bounced and that the momentum flywheel was being spun down, I hope that any "final" landing will be the right way up. I'd have thought a shape like that would only have a small chance of landing on its feet if it started tumbling.
 

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