This should be interesting--separating a landing module from a spacecraft, then landing it on a small comet that's whizzing along at phenomenal speeds. This attempted landing, has been described by the US project manager Art Chmielewski as "one of the hardest things that has ever been done by the human species".
At the end of the seven-hour trip, a cold-gas thruster system is supposed to be fired to hold the lander steady and keep it from bouncing off the surface while harpoons are shot into the comet to secure it in place. But mission managers at the European Space Operations Center in Darmstadt, Germany, said readings from the lander suggested that the system was not properly activated.
"The cold-gas thruster on top of the lander does not appear to be working, so we will have to rely fully on the harpoons at touchdown," Stephan Ulamec, Philae lander manager at the DLR German Aerospace Center, reported in an ESA blog posting. "We'll need some luck not to land on a boulder or a steep slope."
If the surface is very dense and hard, the recoil from the harpoon thrusts won't have the cold thruster to counteract the harpoon's energy. "for every action there is an equal and opposite reaction" ..........Philae could go flying off the comet and back into space.
[This message has been edited by maryjane (edited 11-12-2014).]
Interesting, what they used to illustrate the size of the comet in their representation of how they expected the landing to proceed. "Imperial Star Destroyer"
Interesting, what they used to illustrate the size of the comet in their representation of how they expected the landing to proceed. "Imperial Star Destroyer"
A nod to the geeks out there. Frankly, that doesn't help me much, as I haven't seen an ISD in person
Originally posted by maryjane: Interesting, what they used to illustrate the size of the comet in their representation of how they expected the landing to proceed.
Maybe they beamed the comet up, . I was looking at your links. I never saw what speed the comet was traveling. I heard on a newscast that it was faster than a speeding bullet. Then I heard 84,000 miles an hour. How did we get a probe up to those speeds after ten years of travel ? I have read we sling shoted around some orbits (two I think).
I think it's a huge waste of money but, they did it. Congratulations are in order, I guess.
------------------ Ron Count Down to A Better America: http://countingdownto.com/countdown/196044 Isn't it strange that after a bombing, everyone blames the bomber, his upbringing, his environment, his culture, his mental state but … after a shooting, the problem is the gun?
My Uncle Frank was a staunch Conservative and voted straight Republican until the day he died in Chicago. Since then he has voted Democrat. Shrug
Maybe they beamed the comet up, . I was looking at your links. I never saw what speed the comet was traveling. I heard on a newscast that it was faster than a speeding bullet. Then I heard 84,000 miles an hour. How did we get a probe up to those speeds after ten years of travel ? I have read we sling shoted around some orbits (two I think).
3 sling shots around Earth and one around Mars. (It's in the Washington Post link I provided as well as in the 300k image in my 2nd post.)
I think it's a huge waste of money but, they did it. Congratulations are in order, I guess.
If man can land a vehicle on a comet, it stands to reason man can one day land one on an asteroid, which may come in pretty handy should an asteroid be discovered that has Earth's name on it.
Not to worry, Ron, I don't think it cost you a cent. Europeans paid for it, so the knowledge gained is free.
Fully aware of that Marvin. Precisely why I left it where I did.
Then again, are we sure none of our "buying friends" foreign policy money didn't pay for it?
------------------ Ron Count Down to A Better America: http://countingdownto.com/countdown/196044 Isn't it strange that after a bombing, everyone blames the bomber, his upbringing, his environment, his culture, his mental state but … after a shooting, the problem is the gun?
My Uncle Frank was a staunch Conservative and voted straight Republican until the day he died in Chicago. Since then he has voted Democrat. Shrug
[This message has been edited by blackrams (edited 11-12-2014).]
It didn't all work as designed. The anchoring harpoons failed to fire, the probe bounced once then settled back "down" on to the comet surface gently. It's there, but nothing but the comet's gravity to hold the 2 travelers together. Battery life on the probe is 67 hrs, unless the solar panels work good enough to power the scientific experiments that have been planned.
I wonder, where the comet will eventually carry Philae............?
I wonder, where the comet will eventually carry Philae............?
Well now, if I told you that............................
------------------ Ron Count Down to A Better America: http://countingdownto.com/countdown/196044 Isn't it strange that after a bombing, everyone blames the bomber, his upbringing, his environment, his culture, his mental state but … after a shooting, the problem is the gun?
My Uncle Frank was a staunch Conservative and voted straight Republican until the day he died in Chicago. Since then he has voted Democrat. Shrug
It didn't all work as designed. The anchoring harpoons failed to fire, the probe bounced once then settled back "down" on to the comet surface gently. It's there, but nothing but the comet's gravity to hold the 2 travelers together. Battery life on the probe is 67 hrs, unless the solar panels work good enough to power the scientific experiments that have been planned.
True, they had three independent systems and it looks like only one fully worked (the ice screws). I guess that's why they designed a triple redundancy.
After 10 years I'm amazed anything worked at all. Speculation was stuff designed and tested in the 80's, picked for use in the 90's, and built in early 00's.
True, they had three independent systems and it looks like only one fully worked (the ice screws). I guess that's why they designed a triple redundancy.
All in all tho, it is a truly amazing and great accomplishment--even 'finding' the comet by the orbiter, and then matching it's speed so Philae could land AND, once Philae separated from Rosetta, it was on it's on, following it's program---no going back, no changing course--no control from Earth. I'm in awe of it all.
[This message has been edited by maryjane (edited 11-13-2014).]
X2! For the first time in human history scientists have been able to reach out and touch a comet, an artifact of the very earliest days of our solar system, and we all get a front row seat to witness the event (... conspiracy theorists aside). Few of us sitting at home in our comfy chairs can even imagine how technically difficult this mission was.
(Click on image for context.)
"Explanation: Yesterday, the first soft landing on a comet took place some 500 million kilometers from planet Earth as the Rosetta mission lander Philae settled on the nucleus of C67/P Churyumov-Gerasimenko. The landing site, dubbed Agilkia, is located near the center of this remarkable image snapped by Philae's ROLIS (ROsetta Lander Imaging System) camera. Taken from a distance of about 3 kilometers the image has a resolution of about 3 meters per pixel at the surface. After Philae's release from the orbiter, its seven-hour long descent was made without propulsion or guidance. Following its descent the lander is in place, though its anchoring harpoon system did not fire. For 2.5 days the lander is intended to conduct its main science mission returning extensive images and data. An extended surface mission may be possible if sunlight and dust conditions allow solar panels to recharge Philae's battery."
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Originally posted by heybjorn:
I love the smell of irony in the morning.
You too?
[This message has been edited by Marvin McInnis (edited 11-13-2014).]
I read a report which said that the spot where it landed doesn't get much sun (1-2 hours per day), which would not be enough to charge the batteries. so they might try to take off and land it again. *crosses fingers*
Eb contra-bass clarinet, mainly. Tenor saxophone, too. Actually, I've played every member of the clarinet and saxophone families at one time or another ... all of them rather badly, I fear. I don't think I've had a horn in my hand since shortly after college. At some point I tried to learn classical guitar, but arthritis soon put an end to that. Then there was my attempt at Scottish bagpipes ...
[This message has been edited by Marvin McInnis (edited 11-13-2014).]
Eb contra-bass clarinet, mainly. Tenor saxophone, too. Actually, I've played every member of the clarinet and saxophone families at one time or another ... all of them rather badly, I fear.
You will fit right in, then.
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Then there was my attempt at Scottish bagpipes ...
No, no, I'm not getting into any of that Satanic stuff.
Yeah, what he said. Excuse me but, I happen to agree that this is one hell of a technical achievement. I just think it's a waste of money, regardless of who paid for it.
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Originally posted by heybjorn:
purveyors of irony sounds like a good name for a band. You play any musical instruments, Marvin?
Would you please pick a name for that darn band? BTW, Marvin, I'd pay good money to see you play those bagpipes. You could join Heybjorn's band.
------------------ Ron Count Down to A Better America: http://countingdownto.com/countdown/196044 Isn't it strange that after a bombing, everyone blames the bomber, his upbringing, his environment, his culture, his mental state but … after a shooting, the problem is the gun?
My Uncle Frank was a staunch Conservative and voted straight Republican until the day he died in Chicago. Since then he has voted Democrat. Shrug
[This message has been edited by blackrams (edited 11-13-2014).]
Patrick, are you and cliffw planning to discuss that topic, as you suggested earlier in the week? I have a thought about it that ties a number of topics together. I do not want to interrupt this celebration of achievement here, though.
Them Europeans are good aren't they? (it's from Bloomberg News--Arrowhead Stadium superimposed on the comet surface to better show the size of the comet.)
I have seen some people (comments sections of different websites) mention the fact that the lander missed the hoped for LZ by about 1/2 kilometer and as a result, Philae now sits in the 'shade' of a cliff and the solar collectors won't work very well. I don't think there is any realistic way to lift the probe from the surface and sit it back down elsewhere tho. Anyone know more about this?
And yet Ron, I don't hear you comment or complain about trillions and trillions of dollars blown on armaments world wide each and every year.
The industrial-military complex have a great thing going for themselves.
This money spent on space research is comparatively an absolute drop in the bucket.
You are 100% correct, I'd rather see that money spent on providing our troops with everything they need to defeat our enemies.
BTW, I'm not knocking NASA, I simply don't support this particular mission.
------------------ Ron Count Down to A Better America: http://countingdownto.com/countdown/196044 Isn't it strange that after a bombing, everyone blames the bomber, his upbringing, his environment, his culture, his mental state but … after a shooting, the problem is the gun?
My Uncle Frank was a staunch Conservative and voted straight Republican until the day he died in Chicago. Since then he has voted Democrat. Shrug
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