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| Rosetta: concerns for comet lander after uneven landing | Rosetta: concerns for comet lander after uneven landing |
| (about 1 hour later) | |
| After a historic but awkward comet landing, the robot probe Philae is now stable and sending pictures - but there are concerns about its battery life. | After a historic but awkward comet landing, the robot probe Philae is now stable and sending pictures - but there are concerns about its battery life. |
| The lander bounced twice, initially about 1km back out into space, before settling in the shadow of a cliff, 1km from its intended target site. | The lander bounced twice, initially about 1km back out into space, before settling in the shadow of a cliff, 1km from its intended target site. |
| It may now be problematic to get enough sunlight to charge its battery systems. | It may now be problematic to get enough sunlight to charge its battery systems. |
| Launched in 2004, the European Space Agency (Esa) mission hopes to learn about the origins of our Solar System. | Launched in 2004, the European Space Agency (Esa) mission hopes to learn about the origins of our Solar System. |
| It has already sent back the first images ever taken from the crumbling, fractured terrain of a comet. | It has already sent back the first images ever taken from the crumbling, fractured terrain of a comet. |
| Philae got to the icy 67P/Churyumov-Gerasimenko on the back of Esa's Rosetta satellite after a 10-year, 6.4 billion-km (4bn-mile) journey, which reached its climax on Wednesday with a seven-hour drop to the surface. | Philae got to the icy 67P/Churyumov-Gerasimenko on the back of Esa's Rosetta satellite after a 10-year, 6.4 billion-km (4bn-mile) journey, which reached its climax on Wednesday with a seven-hour drop to the surface. |
| After showing an image that indicates Philae's presumed location - on the far side of a large crater that was earlier considered but then rejected as a landing site - the head of the lander team, Dr Stephan Ulamec, said: "We could be somewhere in the rim of this crater, which could explain this bizarre… orientation that you have seen." | After showing an image that indicates Philae's presumed location - on the far side of a large crater that was earlier considered but then rejected as a landing site - the head of the lander team, Dr Stephan Ulamec, said: "We could be somewhere in the rim of this crater, which could explain this bizarre… orientation that you have seen." |
| Pictures taken by Philae of its surroundings show it pressed up against what appears to be a hard wall of some kind. | Pictures taken by Philae of its surroundings show it pressed up against what appears to be a hard wall of some kind. |
| Telemetry indicates it is on a slope or perhaps even on its side. | Telemetry indicates it is on a slope or perhaps even on its side. |
| Certainly, one of its three feet is not in contact with the surface. | Certainly, one of its three feet is not in contact with the surface. |
| The key issue vexing controllers right now is the lighting conditions. | The key issue vexing controllers right now is the lighting conditions. |
| Philae is receiving about 1.5 hours of illumination during every 12-hour rotation of the comet. | Philae is receiving about 1.5 hours of illumination during every 12-hour rotation of the comet. |
| This will be insufficient to top up its battery system once the primary charge it had on leaving Rosetta runs out. That was some 60-plus hours. | This will be insufficient to top up its battery system once the primary charge it had on leaving Rosetta runs out. That was some 60-plus hours. |
| It means Philae is unlikely to be operating in its present state beyond Saturday. | It means Philae is unlikely to be operating in its present state beyond Saturday. |
| "We have estimations right now that go between Friday afternoon and Saturday afternoon," explained Paolo Ferri, the head of Esa's operations here in Darmstadt, Germany. | |
| "It depends on the activities, of course. The more activities we do with the lander, the more power we will consume, and the less time we will have." | "It depends on the activities, of course. The more activities we do with the lander, the more power we will consume, and the less time we will have." |
| Engineers are examining how they might re-orientate the robot to maximise the light reaching its solar panels. | Engineers are examining how they might re-orientate the robot to maximise the light reaching its solar panels. |
| More extreme options being considered even include using some of the moving parts on the lander to try to make a hopping motion that would carry it clear of the shadows. | More extreme options being considered even include using some of the moving parts on the lander to try to make a hopping motion that would carry it clear of the shadows. |
| But, in truth, there is probably insufficient time to plan and then execute such a strategy. | But, in truth, there is probably insufficient time to plan and then execute such a strategy. |
| The priority right now is to use Philae to acquire as much information as possible about the comet. | The priority right now is to use Philae to acquire as much information as possible about the comet. |
| In this regard, researchers are thrilled by the performance of the probe. | In this regard, researchers are thrilled by the performance of the probe. |
| However, they would dearly love to use the lander's drill. This was one of the key objectives of the mission - to pull up sub-surface material for chemical analysis in onboard labs. | However, they would dearly love to use the lander's drill. This was one of the key objectives of the mission - to pull up sub-surface material for chemical analysis in onboard labs. |
| But the team currently cannot contemplate such an operation with the probe so delicately positioned on only two feet. The drill's rotational forces could destabilise Philae. | But the team currently cannot contemplate such an operation with the probe so delicately positioned on only two feet. The drill's rotational forces could destabilise Philae. |
| Controllers will see what they can do to lower the third foot to the surface. | Controllers will see what they can do to lower the third foot to the surface. |
| If that is not possible, drilling may be commanded towards the end of the primary battery window. By then, scientists would have little to lose anyway. | If that is not possible, drilling may be commanded towards the end of the primary battery window. By then, scientists would have little to lose anyway. |
| "This is a very typical operational decision," said Paolo Ferri. "You gather everything you can first, and then the risky things - you only do them at the end." | "This is a very typical operational decision," said Paolo Ferri. "You gather everything you can first, and then the risky things - you only do them at the end." |
| Whatever happens in the hours ahead, the mission is already assured of its place in history. | Whatever happens in the hours ahead, the mission is already assured of its place in history. |
| Its data - and that from Rosetta which continues to observe from overhead - will transform what we know about comets, and enable researchers to test several hypotheses about the formation of the Solar System and the origins of life. | Its data - and that from Rosetta which continues to observe from overhead - will transform what we know about comets, and enable researchers to test several hypotheses about the formation of the Solar System and the origins of life. |
| One theory holds that comets were responsible for delivering water to the planets. Another idea is that they could have "seeded" the Earth with the chemistry needed to help kick-start biology. | One theory holds that comets were responsible for delivering water to the planets. Another idea is that they could have "seeded" the Earth with the chemistry needed to help kick-start biology. |
| "It has been an absolutely magnificent two days," said Esa mission manager Fred Jansen. | "It has been an absolutely magnificent two days," said Esa mission manager Fred Jansen. |
| "I never thought when I got this job a year and a half ago that this would be the impact. | "I never thought when I got this job a year and a half ago that this would be the impact. |
| "Of course, when you're successful, like the lander now is, taking measurements on the surface, you'd like to continue this for as long as possible. But reality tells us there is a limited amount of battery power." | "Of course, when you're successful, like the lander now is, taking measurements on the surface, you'd like to continue this for as long as possible. But reality tells us there is a limited amount of battery power." |
| Mission facts: | Mission facts: |
| Philae lander | Philae lander |
| Comet 67P | Comet 67P |
| Can you land on a comet? | Can you land on a comet? |
| 'More black swan than yellow duck' | 'More black swan than yellow duck' |
| Brief encounters with comets | Brief encounters with comets |