I watched this documentary called "To catch a comet" about the Rosette/Philae mission to comet Churyumov–Gerasimenko. The achievement of getting to the comet and landing Philae, like many other achievements in space, is really phenomenal. So many things could've gone wrong, but the fact that the worst was Philae bouncing and getting stuck in a dark place (and not being able to perform fully) is a huge success beset by an issue of a smaller magnitude.<p>The description of the documentary says [1]:<p>> Unable to carry enough fuel owing to weight restrictions, the Rosetta scientists devised a delicate cat and mouse trajectory to reach their distant destination. In the ten years Rosetta had been in space she flew around the Earth three times, Mars once and the asteroid belt twice, to gain the momentum she needed to reach her destination. In the months before landing, the team navigated Rosetta safely to a world never before observed at such distances or accuracy. Rosetta orbited the comet before releasing Philae onto the surface.<p>Quoting from the article of this thread:<p>> “We were beginning to think that Philae would remain lost forever. It is incredible we have captured this at the final hour.”<p>This brings a much better ending for the people who worked on the mission for more than 30 years. [1] We tend to anthropomorphize things like spacecrafts, landers, rovers and many other inanimate objects. I think for the team (and many others following this news), this photo would be like being able to see a dear friend one last time, say goodbye in their minds and have some kind of closure.<p>The Wikipedia article, and especially the section titled "Landing and surface operations" [2], is also quite interesting to read.<p>[1]: <a href="http://www.pbs.org/program/catch-comet/" rel="nofollow">http://www.pbs.org/program/catch-comet/</a><p>[2]: <a href="https://en.wikipedia.org/wiki/Philae_(spacecraft)#Landing_and_surface_operations" rel="nofollow">https://en.wikipedia.org/wiki/Philae_(spacecraft)#Landing_an...</a>
I didn't get why this was important and the article didn't reveal it upon skimming. Since it seems to get people very enthusiastic I gave it a proper read. After 11 paragraphs, the actual news is revealed:<p>> “This [...] means that we now have the missing ‘ground-truth’ information needed to put Philae’s three days of science into proper context, now that we know where that ground actually is!”
The hi-res image shows how just how unlucky a landing spot this was.<p><a href="http://www.esa.int/spaceinimages/Images/2016/09/OSIRIS_narrow-angle_camera_image_with_Philae_2_September" rel="nofollow">http://www.esa.int/spaceinimages/Images/2016/09/OSIRIS_narro...</a>
From Wikipedia about the comet: "One of the most outstanding discoveries of the mission so far is the detection of large amounts of free molecular oxygen (O
2) gas surrounding the comet. Current solar system models suggest the molecular oxygen should have disappeared by the time 67P was created, about 4.6 billion years ago in a violent and hot process that would have caused the oxygen to react with hydrogen and form water. Molecular oxygen has never before been detected in cometary comas. In situ measurements indicate that the O
2/H
2O ratio is isotropic in the coma and does not change systematically with heliocentric distance, suggesting that primordial O
2 was incorporated into the nucleus during the comet's formation. Detection of molecular nitrogen (N
2) in the comet suggests that its cometary grains formed in low-temperature conditions below 30 K (−243.2 °C; −405.7 °F)." [1]<p>[1]: <a href="https://en.wikipedia.org/wiki/67P/Churyumov%E2%80%93Gerasimenko" rel="nofollow">https://en.wikipedia.org/wiki/67P/Churyumov%E2%80%93Gerasime...</a>
"At 2.7 km, the resolution of the OSIRIS narrow-angle camera is about 5 cm/pixel, sufficient to reveal characteristic features of Philae’s 1 m-sized body and its legs, as seen in these definitive pictures."<p>I looked at the pictures and the human eye can barely see the lander. Considering that the chances of losing these landers is not that low, I don't understand why they don't make them visually more distinctive.<p>Andrew Ng gave a talk recently where he talks about designing the autonomous cars not for aesthetics, but predictability (via visual distinctiveness). [1] In the same spirit, shouldn't there be efforts to make these spacecraft modules more visually distinctive?<p>[1] <a href="https://www.youtube.com/watch?v=4eJhcxfYR4I&t=16m35s" rel="nofollow">https://www.youtube.com/watch?v=4eJhcxfYR4I&t=16m35s</a>
At some point in the future, someone is going to fly to that comet, land, get out of their vessel and walk over to Philae and smile, give it a pat on the head, and then take it home; someone in the future is going to be lucky enough to experience that task and become a part of its history.
I found ESA's "Rosetta and Philae Cartoons" videos strangely touching: <a href="https://www.youtube.com/playlist?list=PLgx5PMpgonqUD1aO3g0bZ_a7VKg8VGTeS" rel="nofollow">https://www.youtube.com/playlist?list=PLgx5PMpgonqUD1aO3g0bZ...</a><p>I hope they finish the series!
The XKCD already updated the live comic about this subject [1].<p>All panels are available at its sister wiki [2]<p>In my opinion it is a beautiful work of art, pushing the limits of what the media allow the artist to do (the media in this case being comic strips in the webcomic format.<p>[1] <a href="https://xkcd.com/1446/" rel="nofollow">https://xkcd.com/1446/</a><p>[2] <a href="https://www.explainxkcd.com/wiki/index.php/1446:_Landing/All_pictures" rel="nofollow">https://www.explainxkcd.com/wiki/index.php/1446:_Landing/All...</a>
Rosetta also tweeted an update ;)<p><a href="https://twitter.com/ESA_Rosetta/status/772818246059823104" rel="nofollow">https://twitter.com/ESA_Rosetta/status/772818246059823104</a>
NASA and ESA's recent push to land things on comets and asteroids makes me pause and wonder if they have in the last decade or so calculated the orbit of an object that concerns them.
Why did it take so many months for the orbiter to get a photo?<p>Compared to the rest of the achievements of this mission, it seems like this should have been relatively easy: 67P is all of like 2.5 miles wide and the orbit is at like 10 miles. You'd think that a few high res photos in a single orbit would capture nearly every inch of the entire rock.
Unless other parts of the comet is more flat, that landing gear design seems clearly wrong. It included bolting itself to the surface, if I remember correctly, but it seems almost impossible to fixate three legs with almost no gravity on that surface.