{"id":16721,"date":"2014-12-23T17:43:37","date_gmt":"2014-12-23T09:43:37","guid":{"rendered":"https:\/\/wp-productionenv-bjg9h2g2bgg5b8aa.southeastasia-01.azurewebsites.net\/news\/scientific-riches-await-philae-comet-lander-if-it-wakes-up\/"},"modified":"2014-12-23T17:43:37","modified_gmt":"2014-12-23T09:43:37","slug":"scientific-riches-await-philae-comet-lander-if-it-wakes-up","status":"publish","type":"post","link":"https:\/\/starpath.global\/news\/scientific-riches-await-philae-comet-lander-if-it-wakes-up\/","title":{"rendered":"Scientific riches await Philae comet lander, if it wakes up"},"content":{"rendered":"
\"This
This four-image mosaic comprises images taken from a distance of 20.1 kilometers (12.5 miles) from the center of comet 67P\/Churyumov-Gerasimenko on Dec. 10. Credit: ESA\/Rosetta\/NAVCAM<\/figcaption><\/figure>\n

Optimistic Europe\u2019s hibernating Philae comet lander can be revived, mission controllers plan to try and contact the spacecraft as soon as January as the search narrows for the probe\u2019s final resting place \u2014 an unlikely site within arm\u2019s reach of pristine ice and organic matter scientists are eager to analyze if the mission gets a new lease on life.<\/p>\n

Officials have triangulated Philae\u2019s location to within an error of 100 meters \u2014 about 330 feet \u2014 by analyzing radio signals exchanged between the lander and the Rosetta orbiter once the craft settled on the surface of comet 67P\/Churyumov-Gerasimenko.<\/p>\n

Hoping to re-establish communications with the lander next year, scientists have tasked Rosetta\u2019s main camera to survey the region where Philae ended up Nov. 12 after bouncing across the comet for nearly two hours.<\/p>\n

Finding Philae is a matter of time, officials said in a Dec. 17 press briefing at the American Geophysical Union\u2019s fall meeting in San Francisco.<\/p>\n

\u201cIt\u2019s a bit like waiting for Christmas presents,\u201d said Matt Taylor, Rosetta\u2019s project scientist from the European Space Agency.<\/p>\n

Once they identify the location of the lander, scientists will start regularly pinging Philae and listening for a response, according to Jean-Pierre Bibring, Philae\u2019s lead scientist from the Institut d\u2019Astrophysique Spatiale in Orsay, France.<\/p>\n

Philae is wedged against a cliff or boulder that eclipses much of the light and heat coming from the sun, but measurements from the lander\u2019s instruments soon after the Nov. 12 landing showed temperatures should not get cold enough to damage the probe\u2019s sensitive electronic innards.<\/p>\n

Comet 67P\/Churyumov-Gerasimenko is racing into the inner solar system, with its closest brush with the sun expected in August 2015. As the comet closes in on the sun, temperatures on its surface will rise and sunlight will grow more intense, allowing Philae\u2019s solar panels to generate more electricity.<\/p>\n

Bibring said the lander needs another 5 to 7 watts of electricity beyond its current power load to execute a science sequence, and guessing when Philae will have the required power depends on exactly where the craft is situated.<\/p>\n

\"Artist's
Artist\u2019s concept of the Philae lander. Credit: DLR<\/figcaption><\/figure>\n

Rosetta\u2019s OSIRIS camera took a series of images of Philae\u2019s suspected final landing site from Dec. 12 to Dec. 14, according to Holger Sierks, the OSIRIS imager\u2019s principal investigator from the Max Planck Institute for Solar System Research in Gottingen, Germany.<\/p>\n

Sierks says the lander will certainly be in the latest OSIRIS images. Assuming it is illuminated by the sun, Philae should be found.<\/p>\n

\u201cThe question is how much power we get is really a function of where we are,\u201d Bibring said. \u201cThat\u2019s why we are desperately trying to have OSIRIS locate us now. We have done all we could with the data we have now.<\/p>\n

Philae\u2019s solar panels only catch sunlight for a fraction of the comet\u2019s 12.4-hour day<\/p>\n

\u201cThe next question is do we have the survival capability to wait until February or so,\u201d Bibring said. \u201cThis has to do with the temperature inside. We have been qualified for a temperature which is typically minus 65 (degrees Celsius), with a margin of 10 degrees. That means that probably down to minus 75 or minus 80 (degrees), we are in good shape.\u201d<\/p>\n

Philae has thermal insulation designed to keep its internal avionics at a comfortable temperature, and the lander weathered cold temperatures during years of hibernation while riding piggyback on its Rosetta mothership from Earth to the comet.<\/p>\n

\u201cThe question is whether or not some of the electronics suffer from the cold,\u201d Bibring said. \u201cA lot of our systems were designed to sustain very low temperatures. We knew that we would have to operate in a very low temperature envrionment. The only question really is the inside.\u201d<\/p>\n

\u201cWhen putting all that together, I think that within the team there is no doubt that we will wake up, and the question is in what shape,\u201d Bibring said. \u201cMy suspicion is that we will be in good shape.\u201d<\/p>\n

\"From
From the location where it came to rest after bounces, the CIVA camera on Europe\u2019s Philae lander captured this view of a cliff on the nucleus of comet 67P\/Churyumov-Gerasimenko. The feature is called \u201cPerihelion Cliff\u201d and contains blocks of dust-covered ice separated by cracks, materials scientists are eager to analyze if Philae wakes up from hibernation. Credit: ESA\/Rosetta\/Philae\/CIVA<\/figcaption><\/figure>\n

Stephan Ulamec, the lander\u2019s manager from Germany, agrees prospects are good for Philae\u2019s resurrection.<\/p>\n

\u201cI\u2019m quite confident it will wake up again when we are closer to the sun,\u201d Ulamec said in an interview with Spaceflight Now. \u201cWhat will be very interesting is if it gets warm enough to recharge the battery and really do experimental runs. This we can only answer if we have a better feeling on the actual position because we can estimate the illumination when the seasons change.\u201d<\/p>\n

The proof will come if Philae calls home, and the lander\u2019s exact state will not be known until scientists hear from it.<\/p>\n

\u201cThis we will know only when we turn on the system,\u201d Bibring said. \u201cAs soon as we know where we are, we will try, and that might be as early as January of next year.\u201d<\/p>\n

Exactly when Philae will wake up and radio home is also unclear. Bibring estimates the probe will have sufficient power to switch on in the first half of 2015 \u2014 after Easter (April 5) in the most \u201cpessimistic\u201d scenario, or as soon as February or March if things go better.<\/p>\n

Ulamec, who is based at DLR\u2019s lander control center in Cologne, says Philae is somewhere near a crater rim on the smaller lobe of Churyumov-Gerasimenko \u2014 based on radio ranging data between Philae and Rosetta. The comet is made of two parts separated by a neck, resembling the head and body of a duck.<\/p>\n

\u201cWe expect to be somewhere at the crater rim,\u201d Ulamec said in an interview with Spaceflight Now. \u201cThat\u2019s quite clear, but it\u2019s not 100 percent clear whether it\u2019s a little bit inside or a little bit outside of this rim of the major crater on the head of the duck.\u201d<\/p>\n

As scientists look for the lander with Rosetta, a detailed analysis of imagery captured by Philae shows the craft ended up at a site ripe for study.<\/p>\n

Blocks of blackened cryogenic water ice covered with a dark dusting of organic matter were seen within feet \u2014 tens of centimeters \u2014 of the lander, Bibring said.<\/p>\n

\u201cWe\u2019re in a hole, in the shadow of something, so essentially you have these blocks of pristine material still there,\u201d Bibring said. \u201cWe have a large diversity of materials ahead of us, much larger than we hoped actually. Probably, these are the pristine building blocks (of life) with a lot of ice loaded with organics. These are the materials we were desperately looking for.\u201d<\/p>\n

\"This
This graphic depicts the position of the Philae lander of the European Space Agency\u2019s Rosetta mission, and a nearby cliff photographed by the lander, in the context of topographic modeling of the surface of comet 67P\/Churyumov-Gerasimenko\u2019s nucleus. Credit: ESA\/Rosetta\/Philae\/CNES\/FD\/CIVA<\/figcaption><\/figure>\n

Philae collected 16 megabytes of data \u2014 about 90 percent of its planned initial data cache \u2014 in a feverish two-day science campaign before running out of battery power, Ulamec said.<\/p>\n

Scientists activated all 10 of Philae\u2019s science instruments before the lander shut down. But Bibring says the lander\u2019s drill \u2014 despite deploying and functioning as designed \u2014 may not have collected a sample for delivery into the probe\u2019s miniaturized on-board laboratory for analysis.<\/p>\n

Evidence indicates an oven inside one of Philae\u2019s instruments apparently did not receive a specimen from the drill, according to Bibring. The device was supposed to heat up the sample and measure vapors coming off the dust and ice to determine its chemical make-up.<\/p>\n

If the lander does come back to life \u2014 as predicted \u2014 Ulamec hopes Philae will function for several months. After worrying about the lander overheating as the comet flies into a warmer environment next year, Ulamec says Philae\u2019s shadowed surroundings could keep the probe cool enough to survive perihelion, the point where the Churyumov-Gerasimenko comes closest to the sun.<\/p>\n

\u201cOur fear was overheating in the March-April timeframe, but now it\u2019s not overheating that is the problem,\u201d Ulamec said. \u201cIt\u2019s the hope that we get warm enough, but the chances are good.\u201d<\/p>\n

Philae is about the size of a kitchen oven or dishwasher, and its cost spread across Europe\u2019s national space agencies \u2014 led by Germany\u2019s DLR \u2014 was approximately 220 million euros, or $270 million. It launched from Earth with ESA\u2019s Rosetta mission in March 2004 and arrived in the vicinity of the comet in August 2014.<\/p>\n

After its release from Rosetta, Philae descended to the comet for seven hours before touching down near the lander\u2019s target, a relatively smooth region selected to maximize the probe\u2019s chances of achieving a successful landing and collecting enough sunlight for an extended mission.<\/p>\n

But two of Philae\u2019s landing systems failed.<\/p>\n

A thruster designed to push the lander into the comet\u2019s surface did not pressurize before Philae\u2019s separation from Rosetta, then two harpoons that were supposed to fire to anchor the spacecraft to the comet failed to engage. Taylor said ESA will soon begin an investigation into why the landing aids misfired.<\/p>\n

The comet\u2019s crust also turned out to be more rigid than expected, causing Philae to bounce hundreds of feet back into space before finally coming to a stop after a two-hour tumble across the comet nucleus.<\/p>\n

In a presentation at the AGU meeting in San Francisco last week, Bibring showed a blurred image from Philae\u2019s camera captured during the lander\u2019s bounce. He said the science team was shocked by the photo, which was received as mission control was still in the fog of figuring out what happened to the spacecraft.<\/p>\n

Officials worried whether the lander had rebounded into space and was lost forever.<\/p>\n

\"An
An image from Philae\u2019s initial touchdown on comet 67P\/Churyumov-Gerasimenko, blurred from the lander\u2019s motion as it bounced across the comet. Credit: ESA\/Rosetta\/Philae\/CIVA<\/figcaption><\/figure>\n

\u201cAt that time, which was only a few minutes or an hour after we landed, it was terrible because we did not know at that time whether or not the ejection velocity was higher or lower than the escape velocity,\u201d Bibring said.<\/p>\n

Churyumov-Gerasimenko\u2019s gravity is so weak that the Philae landing craft, which measured 220 pounds on Earth, only weighs as much as a paperclip on the comet. If the lander bounced hard enough, it could have had enough speed to break free of the comet\u2019s feeble gravity and fly away into space, never to return.<\/p>\n

The events made for a \u201cnightmare night,\u201d Bibring said.<\/p>\n

\u201cIt was very acrobatic,\u201d Bibring said. \u201cIt was not obvious that we would make it, but we did make it. We are in a place that was almost impossible to reach. Of course, you can\u2019t land close to a cliff, but we are there now.\u201d<\/p>\n

Follow Stephen Clark on Twitter: @StephenClark1.<\/i><\/b><\/p>\n","protected":false},"excerpt":{"rendered":"

This four-image mosaic comprises images taken from a distance of 20.1 kilometers (12.5 miles) from the center of comet 67P\/Churyumov-Gerasimenko on Dec. 10. Credit: ESA\/Rosetta\/NAVCAM Optimistic Europe\u2019s hibernating Philae comet lander can be revived, mission controllers plan to try and contact the spacecraft as soon as January as the search narrows for the probe\u2019s final […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"inline_featured_image":false,"footnotes":"","_links_to":"","_links_to_target":""},"categories":[2],"tags":[4200,3098,3573,1914,3609,3373],"class_list":["post-16721","post","type-post","status-publish","format-standard","hentry","category-news","tag-agu-2014","tag-comet-67p-churyumov-gerasimenko","tag-comet-landing","tag-dlr","tag-philae","tag-rosetta"],"acf":[],"_links":{"self":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/16721"}],"collection":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/comments?post=16721"}],"version-history":[{"count":0,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/16721\/revisions"}],"wp:attachment":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/media?parent=16721"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/categories?post=16721"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/tags?post=16721"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}