Rosetta mission: Philae lander is 'Go' for attempted comet touchdown

[GourmetDan]

Rosetta mission: Philae lander is 'Go' for attempted comet touchdown

"Rosetta mission controllers have made the first call to "Go" for an attempted landing on Comet 67P, the European Space Agency (ESA) announced in a webcast Tuesday."

The Philae lander is unlikely to be able to attach to the comet with it's 'harpoon' and 'ice screws' because comets are not 'dirty snowballs'.  They are rocks no different than an asteroid and are simply on an elongated orbit.  The cometary discharge is electrical in nature as the negatively-charged comet comes closer to the positively-charged sun.

Tomorrow will be interesting...

[GourmetDan]

These guys have a much better grasp of what comets are than Bill Nye and the ESA

Wal Thornhill and David Talbott on Rosetta | Space News

[GourmetDan]

Cosmic 1st: European spacecraft lands on comet

"Philae was supposed to have drifted down to the comet and latched on using harpoons and ice screws. Ferri said thrusters meant to push the lander down failed to deploy, and there appeared to have been a problem with the harpoons as well that is now being investigated. But he added that Philae seemed to be stable on the surface of the comet."

"Scientists also noted a problem with the signal from the lander, which they are now trying to fix."

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The 'harpoons' and 'ice screws' weren't designed to penetrate solid rock and it probably turned over...

[GourmetDan]

European scientists make space history by successfully landing probe on a comet after 10-year mission - but reveal Philae BOUNCED on the surface as harpoons supposed to tether it did not fire

"However, while the lander has touched down on the comet using its harpoons, scientists said that it had not yet deployed its anchors which meant that it was not completely attached to the surface.

The surface was much softer than they expected, so there were some concerns that it was not securely fixed on the comet – although from a software point of view things seemed to be fine.

Engineers will attempt to fire the anchors again soon in order to keep Philae attached to the surface of the comet."

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Text inconsistent wrt 'harpoons' and surface 'softer than expected' yet it 'bounced'.  Picture at link shows what looks like lots of dust on the surface.

[GourmetDan]

The Rosetta comet is singing: as the orbiter approaches, the ESA uploads audio of the comet's warbling magnetic 'song'

"The 'song' - thought to be caused by oscillations in the comet's electrically charged pseudo-atmosphere - is well below the threshold of human hearing"

As the Rosetta orbiter nears the comet Churyumov-Gerasimenko 67P and prepares to fire the Philae lander at its surface, scientists from the European Space Agency (ESA) have been puzzled by an unexpected phenomenon: the comet is ‘singing’.

Instruments designed to analyse the plasma environment surrounding 67P have recorded a low, bubbling song (listen below) though to be created by a stream of electrically charged particles released as the comet hurtles through space at 34,175mph.

“This is exciting because it is completely new to us,” said Karl-Heinz Glaßmeier, principal investigator with Rosetta’s Plasma Consortium (RPC) in a press statement. “We did not expect this and we are still working to understand the physics of what is happening.”

Ooh, unexpected 'electrical effects'.

Like all comets, 67P has magnetic pseudo-atmosphere known as a ‘coma’ - activated as the 4km long chunk of ice draws closer to the Sun and solar winds whip up electrically charge particles of gas and dust.

The 'solar wind' is a flow of protons being accelerated from the sun toward the negatively-charged heliopause.  Comet 67P is more negatively-charged than the solar wind because of the time spent at the far reaches of the solar system.  Those 'solar wind' protons interact with 67P generating the coma and jets as they electrically-machine dust off of the surface of the comet.

No ice... no sublimation from heat... just electrical effects...

Should listen to the EU guys more?

[GourmetDan]

Philae lander sends back first ever image from comet surface

"The European Space Agency’s Philae lander has sent back the first ever image from the surface of a comet.

The picture shows the cracked, bumpy surface in monochrome, with one of Philae’s three legs in the bottom left of the frame. It is not yet clear whether the leg in the image is actually touching the surface. What is certain is that Philae is not level, and may be wedged into a pit.

“We’re either looking into a ditch or we are against a wall,” said ESA Rosetta project scientist Matt Taylor."

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May have tipped over because it isn't attached to the solid rock surface of the comet...

[SPQR]

These guys have a much better grasp of what comets are than Bill Nye and the ESA

Wal Thornhill and David Talbott on Rosetta | Space News

Nye began his career in Seattle at Boeing, where (among other things) he starred in training films and developed a hydraulic pressure resonance suppressor for the 747. Later, he worked as a consultant in the aeronautics industry. In 1999 he told the St. Petersburg Times that he applied to be a NASA astronaut every few years, but was always rejected. He is also President of the Planetary Society formerly held by the the position of Dr. Carl. SaganIn the early 2000s, Nye assisted in the development of a small sundial that was included in the Mars Exploration Rover missions.Known as MarsDial, it included small colored panels to provide a basis for color calibration in addition to helping keep track of time

[GourmetDan]

As hard as ice: Scientists reveal first details of the comet Philae landed on - and say they are 'very confident' the lander WILL come back to life in spring next year

"'The strength of the ice founds under a layer of dust on the first landing site is surprisingly high,' says Klaus Seidensticker from the DLR Institute of Planetary Research."

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Next they'll say that the core drill has apparently had the misfortune to hit a rock embedded in the ice. 

Getting rid of 'scientific assumptions' is always the hardest part...