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2014/11/11 23:58:28
Subject: Landing attempt on a comet: ESA's Rosetta mission
ESA's Rosetta mission has entered another critical phase that will culminate tomorrow morning (12th of November) at about half past eight (GMT) with the release of the small robotic probe Philae and its hopefully safe touchdown seven hours later in an attempt to land said probe on the comet 67P/Churyumov–Gerasimenko. If all works as planned it will be the first successful landing of a human device on a comet and might offer important insights into how life in the form of water and amino-acids came to earth.
The probe itself will fall towards the comet without any kind of additional guidance and all depends on the actual landing spot that's far from perfect with large boulders, and steep slopes and the accuracy of Rosetta's initial trajectory, release time, and speed. Once it has touched down the probe has a few thrusters to keep it briefly on the surface and prevent it from bouncing back into space while several harpoons and drills try to secure it on the frozen ground since the comet's gravitational field would be too weak to hold the probe down.
All in all a very risky and ambitious endeavour with various tragic ways to fail. But even in that not too unlikely case of a failed landing the actual space craft Rosetta will continue to orbit and follow the comet for another year and take measurements of the changing comet as it flies ever closer to the sun.
The whole mission began about ten years ago with the launch of Rosetta in French Guiana. Initially the probe was scheduled for an earlier start and a different comet and needed to be reprogrammed several times during its journey. Since then the probe has traveled 6,550 million km speeding multiple times past Earth and Mars to steal some of the planets angular momentum to build up speed and change course for the comet rendezvous. The resulting trajectory looks quite impressive and complicated for a very precise ten year long manoeuvre:
The ESA website has another interactive trajectory display and photos taken from Churyumov–Gerasimenko.
Early landing site selection (only possible after Rosetta reached the comet and started taking images of the shape and surface of the comet):
Spoiler:
Planned measurements during Philae's descent:
Spoiler:
Orbit changes and lander deployment:
Spoiler:
Short film to commemorate the upcoming landing attempt:
Spoiler:
That's how the actual landing might look like for someone standing on the surface of the comet (perhaps without the thrusters on top though):
Spoiler:
----
Update:
ESA wrote:During checks on the lander’s health, it was discovered that the active descent system, which provides a thrust to avoid rebound at the moment of touchdown, cannot be activated.
At touchdown, landing gear will absorb the forces of the landing while ice screws in each of the probe’s feet and a harpoon system will lock Philae to the surface. At the same time, the thruster on top of the lander is supposed to push it down to counteract the impulse of the harpoon imparted in the opposite direction.
Update 10:12 (GMT): The lander has been separated from Rosetta and is currently on its slow descent towards the comet's surface:
ESA wrote:The Philae lander has separated from the Rosetta orbiter, and is now on its way to becoming the first spacecraft to touch down on a comet.
Separation was confirmed at ESA’s Space Operation Centre, ESOC, in Darmstadt, Germany at 09:03 GMT / 10:03 CET. It takes the radio signals from the transmitter on Rosetta 28 minutes and 20 seconds to reach Earth, so separation actually occurred in space at 08:35 GMT / 09:35 CET.
First images are radio contact between Philae and Rosetta is expected at about 11:00 (GMT) and has indeed been established at 11:07 GMT. It shouldn't be too long until we can see the first images.
Update 14:30 (GMT): First image taken by Philae of the Rosetta space craft:
Spoiler:
Update 16:07 GMT:
Philae has landed on the comet!
ESA Twitter wrote:RECEIPT OF SIGNAL FROM SURFACE. receiving signals from @Philae2014 on surface of comet #67P/CG #cometlanding
Update 16:12 GMT:
ESA Twitter wrote:Harpoons confirmed fired & reeled in. Flywheeel now be switched off. @Philae2014 is on the surface of #67P
Can't wait for the first images from the ground.
This message was edited 5 times. Last update was at 2014/11/12 22:47:46
2014/11/12 00:06:42
Subject: Landing attempt on a comet: ESA's Rosetta mission
As a massive space exploration geek, this gives me a serious case of the feels. I think I will be setting my alarm so I can watch the live stream.
I hope so so much that this is successful...!
d-usa wrote: "When the Internet sends its people, they're not sending their best. They're not sending you. They're not sending you. They're sending posters that have lots of problems, and they're bringing those problems with us. They're bringing strawmen. They're bringing spam. They're trolls. And some, I assume, are good people."
2014/11/12 00:39:33
Subject: Landing attempt on a comet: ESA's Rosetta mission
According to this ESA check list the next interesting events and mission critical decisions will be at
ESA wrote:3. THIRD GO/NOGO 01:35 UTC/02:35 CET
Confirm status & health of Philae: The Philae Control Team at the Lander Control Centre (DLR/Cologne) will do a final check and verification of the lander’s health.
ESA wrote:4. FINAL DELIVERY MANOEUVRE (THRUSTER BURN) 06:03-07:03 UTC / 07:03-08:03 CET
Rosetta performs the final lander pre-delivery manoeuvre: This is expected to last about 6 minutes and is planned to place the pair onto the correct delivery trajectory. This new orbit will take Rosetta and Philae to a point about 22.5 km from the comet’s centre for separation.
ESA wrote:5. FOURTH GO/NOGO 06:35-07:35 UTC/07:35-08:35 CET
ESOC will make final GO/NOGO decision on lander separation. There is no way for Philae to return to Rosetta, so separation is a one-time event.
There's also another rather more detailed time table for the upcoming events and of course twitter.
Separation and establishing a radio link were successful as demonstrated with the first (blurry) photo taken by the lander Philae (camera facing upwards roughly toward the Rosetta space craft):
Automatically Appended Next Post: Philae has landed on the comet!
ESA Twitter wrote:RECEIPT OF SIGNAL FROM SURFACE. receiving signals from @Philae2014 on surface of comet #67P/CG #cometlanding
This message was edited 1 time. Last update was at 2014/11/12 16:09:08
2014/11/12 16:16:40
Subject: Landing attempt on a comet: ESA's Rosetta mission
It seems the harpoons to fix the lander on the comet did not fire.
ESA Twitter wrote:More analysis of @Philae2014 telemetry indicates harpoons did not fire as 1st thought. Lander in gr8 shape. Team looking at refire options
Hopefully they'll manage to overcome that problem.
2014/11/12 17:24:53
Subject: Landing attempt on a comet: ESA's Rosetta mission
The fact that these spacecraft are essentially using antique hardware makes it even more astonishing.
Great job, ESA!
d-usa wrote: "When the Internet sends its people, they're not sending their best. They're not sending you. They're not sending you. They're sending posters that have lots of problems, and they're bringing those problems with us. They're bringing strawmen. They're bringing spam. They're trolls. And some, I assume, are good people."
2014/11/12 23:38:23
Subject: Landing attempt on a comet: ESA's Rosetta mission
Totaly amazing when you think that it was shortly after the turn of the last century was the first powered flight.
Serious great learning curve at work here.
2014/11/12 23:57:48
Subject: Re:Landing attempt on a comet: ESA's Rosetta mission
Relapse wrote: Totaly amazing when you think that it was shortly after the turn of the last century was the first powered flight.
Yeah, that's neat to think about.
However, I think the Apollo landings were even crazier: there were people watching it live on their televisions that remember the Wright brothers first flight... they were only separated by 66 years!
d-usa wrote: "When the Internet sends its people, they're not sending their best. They're not sending you. They're not sending you. They're sending posters that have lots of problems, and they're bringing those problems with us. They're bringing strawmen. They're bringing spam. They're trolls. And some, I assume, are good people."
2014/11/13 05:10:35
Subject: Re:Landing attempt on a comet: ESA's Rosetta mission
Waiting for my shill money from Spiral Arm Studios
Well either Comets are shades of grey, or the budget wasn't enough to give a color camera to the lander.
Self-proclaimed evil Cat-person. Dues Ex Felines
Cato Sicarius, after force feeding Captain Ventris a copy of the Codex Astartes for having the audacity to play Deathwatch, chokes to death on his own D-baggery after finding Calgar assembling his new Eldar army.
Stephen Luntz wrote:Graphic Shows The Size Of Rosetta's Comet
Our sense of scale tends to adjust to circumstances. So when we think about comets it is easy to compare them with other astronomical objects. In which case, comet 67P/Churyumov-Gerasimenko –just three kilometers wide –sounds tiny.
However, as you can see in the image above, things look rather different when you compare the comet to something we are really familiar with - such as tall buildings.
While Churyumov-Gerasimenko is small enough that one could walk from one end to the other in less than an hour, it’s easy to forget the three dimensional nature of something like this – three kilometers across is no big deal, but two kilometers helps make sense of what happened to the dinosaurs.
The image is by Matt Wang, who combined a photograph of Los Angeles with an image from the Rosetta spacecraft rendezvousing with Churyumov-Gerasimenko, prior to going into orbit and eventually landing.
While Rosetta will be doing its best to touch down very gently on the comet’s surface, we can’t count on Churyumov-Gerasimenko doing the same if it ever paid LA a visit. You can get some idea of what would happen in such a collision here, although the scale of the damage depends greatly on the impact speed you choose to enter.
Since Churyumov-Gerasimenko never crosses the Earth's orbit there is no danger of a collision, at least until a close encounter with some other planet shifts its orbit. Unfortunately the same cannot be said for other, even larger, asteroids and comets.
This message was edited 1 time. Last update was at 2014/11/13 18:35:04
2014/11/13 20:15:44
Subject: Re:Landing attempt on a comet: ESA's Rosetta mission
Or, do I need to turn in my "Earth First Club" card?
Where we'll strip mine the other planets later!
this was my first thought too, I would love to see a comet pulled into a moon like orbit, hollowed out, and made into a space base once the mining is done.
I also like stroking white cats and twisting my long, fabulous moustache as well though, so maybe its just me....
2014/11/14 21:26:19
Subject: Landing attempt on a comet: ESA's Rosetta mission
It's a shame that the lander's battery probably won't hold out long enough to transmit the data it gathers.
Mandorallen turned back toward the insolently sneering baron. 'My Lord,' The great knight said distantly, 'I find thy face apelike and thy form misshapen. Thy beard, moreover, is an offence against decency, resembling more closely the scabrous fur which doth decorate the hinder portion of a mongrel dog than a proper adornment for a human face. Is it possibly that thy mother, seized by some wild lechery, did dally at some time past with a randy goat?' - Mimbrate Knight Protector Mandorallen.
Excerpt from "Seeress of Kell", Book Five of The Malloreon series by David Eddings.
"You need not fear us, unless you are a dark heart, a vile one who preys on the innocent; I promise, you can’t hide forever in the empty darkness, for we will hunt you down like the animals you are, and pull you into the very bowels of hell." Iron - Within Temptation
2014/11/15 13:58:40
Subject: Re:Landing attempt on a comet: ESA's Rosetta mission
On Wednesday afternoon, the European Space Agency made galactic history when their Rosetta Mission successful landed its Philae probe on a speeding comet, the first time such an extraordinary feat has been achieved.
As with everything from the moon landing to the death of Elvis, an alternative version of “what really happened” as the Philae probe landed on comet 67P did not take long to emerge.
According to an email published on the website UFOSightingsDaily.com – which does a regular trade in alien sightings – this mission is part of a European Space Agency and Nasa cover-up to disguise the comet’s true alien nature. The email, allegedly from a secret whistle-blowing employee of the ESA, accuses the agency of “blatant cover-ups” in wanting to land on the speeding comet and attaches photos which claim to reveal the “true inner workings of Comet 67P”.
It states: “Do not think for ONE MOMENT that a space agency would suddenly decide to spend billions of dollars to build and send a spacecraft on a 12-year journey to simply take some close-up images of a randomly picked out comet floating in space.”
“Comet 67P is NOT a comet,” the letter continues. “Some 20 years ago Nasa began detecting radio bursts from an unknown origin out in space. It would later be known that these had likely come from the direction of the now named comet 67P. It does show signs on its outside of machine like parts and unnatural terrain.”
Ending on an ominous note, it adds: “Whatever this object is, it did not ask to be found or scrutinised.”
Commenting on the article, contributor Scott Waring also said he believed the signals being emitted from the comet were a “greeting” to humans. “If it was a warning, they would not allow the ESA craft to have landed” he wrote. “I believe the landing of the ESA craft was the equivalent of a first handshake. They will make another move soon probably. Alien structures are on the comet. I don’t believe it’s natural. ”
Yet this is far from the only extra-terrestrial conspiracy theory put forward about 67P and the ESA mission. In September, BPEarthWatch published a video showing “brand new, hi-res” images. Taken from the Rosetta spacecraft, they appeared to show two UFOs flying over the comet and a transmission tower-like structure built on the surface, potentially emitting the mysterious radio signals which have been picked by the ESA. “These images are not normal,” says the video voiceover.
ESA’s confirmation that the comet had been emitting a “mystery song” has fuelled theories that it is in fact an alien ship and the warbling is an extra-terrestrial attempt at communication.
Writing on the website UFOSightingsDaily.com, Scott Waring professed that: “In my opinion this is not a code. It is how a species of aliens communicate to one another without speaking. A form of telepathy put into primitive radio signals. Its the only way this species can communicate to us. This is their thoughts. They don’t talk.”
Waring added: “Getting a copy of the full message and then translating it should be of utter importance. Is it a message of greetings? Or is it a warning of what’s to come? We, the people of the world, need to find out.”
On the plus side : " Whatever this object is, it did not ask to be found or scrutinised.” is the line I'm gonna steal and use when I fold this into my RPG campaign.
The poor man really has a stake in the country. The rich man hasn't; he can go away to New Guinea in a yacht. The poor have sometimes objected to being governed badly; the rich have always objected to being governed at all
We love our superheroes because they refuse to give up on us. We can analyze them out of existence, kill them, ban them, mock them, and still they return, patiently reminding us of who we are and what we wish we could be.
"the play's the thing wherein I'll catch the conscience of the king,
2014/11/15 14:10:37
Subject: Re:Landing attempt on a comet: ESA's Rosetta mission
Avatar 720 wrote: It's a shame that the lander's battery probably won't hold out long enough to transmit the data it gathers.
It gets some energy, not enough. When the comet closes with the sun it should get more.
So long as it can power its heaters with the energy it has, everything else can wait.
A partially successful landing is still a successful landing, it just means we have to wait a while longer.
n'oublie jamais - It appears I now have to highlight this again.
It is by tea alone I set my mind in motion. By the juice of the brew my thoughts aquire speed, my mind becomes strained, the strain becomes a warning. It is by tea alone I set my mind in motion.
2014/11/15 15:09:17
Subject: Landing attempt on a comet: ESA's Rosetta mission
