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Rosetta: Waiting game after comet lander glitch
bbc ^ | 12 November 2014 Last updated at 16:35 ET

Posted on 11/12/2014 2:32:04 PM PST by BenLurkin

A European robot probe has made the first, historic landing on a comet, but its status remains uncertain after harpoons failed to anchor it to the surface.

Officials said the craft may have lifted off the comet after touchdown before returning to the surface.

Lander project manager Stephan Ulamec said: "Maybe we didn't just land once, we landed twice."

Further analysis is needed to fully understand the situation.

However, Dr Ulamec told the BBC that at last radio contact with the probe that he believed it to be in a stable configuration.

"This is the indication right now," he explained. "We really have to wait until tomorrow morning and then we will know a lot more."

The "first" landing on Comet 67P/Churyumov-Gerasimenko was confirmed at about 1605 GMT.

There were cheers and hugs at the European Space Agency's mission control in Darmstadt, Germany, after the signal came through.

Early data started to come back from instruments, and one team could see that the lander, known as Philae, had sunk about 4cm (1.5 inches) into the surface, suggesting a relatively soft top layer.

But shortly after, engineers could see that the harpoons, designed to fasten the spacecraft to the 4km-wide (2.5 miles) ball of ice and dust, had not fired as planned..

(Excerpt) Read more at bbc.com ...


TOPICS: Science
KEYWORDS: churyumovgerasimenko; comet67p; philae; rosetta
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To: BenLurkin

So the comet could possibly “throw” the lander off of it?


21 posted on 11/12/2014 3:12:19 PM PST by VanDeKoik
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To: Calvin Locke; tx_eggman

Here’s a Science Fiction thriller for you...

Wouldn’t it be ironic if Philae caused *just* enough disturbance to push the comet into a collision course with Earth in, say, 30 years or so?


22 posted on 11/12/2014 3:17:16 PM PST by SpinnerWebb (IN-SAPORIBVS-SICVT-PVLLVM)
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To: HandyDandy

I thought the gravity was too weak to help if it bounced. Your explanation would make sense, but it runs counter to what I thought I heard on one of the explanatory videos. I can only see too possibilities. One is gravity. The other is that the robot could “bounce” into the path of the comet, or into the path of another part of the comet as it rotated.


23 posted on 11/12/2014 3:21:18 PM PST by jjsheridan5 (Remember Mississippi -- leave the GOP plantation)
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To: christx30
From what I’ve heard about that craft, it has no thrusters. No way of steering. It gets moved into position by its “mother ship” then dropped onto the surface. Nothing holding it on right now except for sheer luck.

It has "cold" thrusters, nitrogen gas jets, to keep it on the surface while it attempts to drill into the surface to anchor it through the landing pads.

24 posted on 11/12/2014 3:23:30 PM PST by Swordmaker (This tag line is a Microsoft insult free zone... but if the insults to Mac users continue...)
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To: jjsheridan5
It would bounce because the landing legs have resilience, the lander is "bouncy" like a spring.

CGI animation of landing

On landing, the legs damp out most of the kinetic energy to reduce the chance of bouncing, and they can rotate, lift or tilt to return the lander to an upright position.
The Rosetta Lander

Because of the comet's extremely low gravity, a landing gear will absorb the small forces occurring during landing while ice screws in the probe's feet and a harpoon system will lock the probe to the surface. At the same time a thruster on top of the lander will push it down to counteract the impulse of the harpoon imparted in the opposite direction.

25 posted on 11/12/2014 3:25:27 PM PST by Cboldt
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To: Daffynition

****Does the EU not know about duct tape?***

How about Sack-Crete?


26 posted on 11/12/2014 3:25:41 PM PST by Don@VB (Power Corrupts)
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To: SpinnerWebb
That'd make a SyFy low budget movie, but don't most comets end by being sucked into the Sun? I lost count of how many SOHO both found and/or watched plummet.

Unless you're going with the Tunguska dead comet theory. Or possibly Shoemaker-Levy 9?

27 posted on 11/12/2014 3:30:15 PM PST by Calvin Locke
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To: HandyDandy
The comet has some gravity. The lander bounced because the grappling and thruster malfunction, while it landed on shock absorbers.

The gravitational acceleration of the comet is very small, calculated to be about 1.5mm/sec^2, so it would not take much of a bounce to send it back into space. . . and a very long time to bring it back down just by a fall. Rosetta IS in a free-fall orbit around it.

I seriously suspect the failure of the harpoons and thrusters occurred because of electrical discharges from the comet disabled them by frying their electronics. The team did say there were other electronic anomalies associated with the landing.

28 posted on 11/12/2014 3:32:34 PM PST by Swordmaker (This tag line is a Microsoft insult free zone... but if the insults to Mac users continue...)
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To: MUDDOG
The Great White Comet.

Uh, nope. Try Great BLACK Comet.


The reconstructed-colour image, taken early October, indicates how dark the comet appears.
On the average, the comet's surface reflects about four per cent of impinging visible light,
making it as dark as coal

29 posted on 11/12/2014 3:37:13 PM PST by Swordmaker (This tag line is a Microsoft insult free zone... but if the insults to Mac users continue...)
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To: jjsheridan5
Still learning about the landing craft ...
There will be two harpoons to anchor it to the surface so that it can be reeled in like a fish on a line. There are also ice screws in each foot, which can be rotated to help to secure the spacecraft on the surface. The lander is also designed to stay upright on a slope of up to 30 degrees.
From Rosetta FAQ
30 posted on 11/12/2014 3:38:31 PM PST by Cboldt
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To: BenLurkin; flaglady47
I heard on the radio news earlier today that the European Space Agency was crowing that the success of the mission (the "success" at that time of day, I might add) was not due to the United States space agency (NASA) or Germany, Britain, Russia, blah, blah....but to "European endeavors".

Well, we'll see how successful it was, probably tomorrow.

Leni

31 posted on 11/12/2014 3:38:41 PM PST by MinuteGal
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To: BenLurkin

Nice piece of rock that God made.


32 posted on 11/12/2014 3:42:18 PM PST by Karl Spooner
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To: MinuteGal

And we’ll be getting an American look at Pluto in July, an American look at dwarf planet Ceres not long after and an American return to Jupiter in 2016.


33 posted on 11/12/2014 3:48:09 PM PST by cripplecreek (You can't half ass conservatism.)
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To: BenLurkin

You and I would weigh 2 grams on the comet.

So a sneeze would be more than escape velocity.

A theory is that the comet is more like a welder’s arc than a pressure cooker of gas. If so, anything conductive would fry.


34 posted on 11/12/2014 4:14:42 PM PST by cicero2k
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To: BenLurkin

PBS video: “To Catch a Comet”

http://video.pbs.org/video/2365367186/


35 posted on 11/12/2014 4:57:28 PM PST by iowamark (I must study politics and war that my sons may have liberty to study mathematics and philosophy)
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To: jjsheridan5

I read the downforce thrust jet was bad ordered... if that is the case what force will oppose the firing of these “harpoons” downward? Does someone need to explain Newton’s first law here to these scientists?


36 posted on 11/12/2014 6:48:59 PM PST by Rodamala
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To: BenLurkin

Update Thursday am GMT: contact reestablished with the lander, now reported ‘stable’ and systems functioning. First image of surface from lander now available.


37 posted on 11/13/2014 3:37:48 AM PST by Winniesboy
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To: Winniesboy

bttt


38 posted on 11/13/2014 7:48:33 AM PST by BenLurkin (This is not a statement of fact. It is either opinion or satire; or both. Hat)
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