Discussion
durbster said:
I do wish they wouldn't refer to it as an "impact site", and let us pretend we think it's going to touch down gently and continue to send us amazing photos 
They're not calling it the landing site as it will probably bounce off and eventually land somewhere else. But they won't know where.
Eric Mc said:
They can't be sure that they maintain contact with the probe once it lands on the surface. The transmissions are spread over a very narrow beam angle so if the surface is not absolutely flat, the transmission dish will be resting at an angle and their is a high possibility that the beam will miss the earth - and transmissions from earth will not be able to reach the probe. The only cautious thing to do is to turn the craft off when they are 100% sure they can communicate with it. And that is what they have done.
It's on the surface of a comet that is now rapidly heading off towards the cold bits of the solar system; why does it matter whether it's turned off or not? I listened to the same Today program interview as Eric. As I understand it, there is a finite amount of bandwidth available for this sort of thing. If there's a device floating around the solar system making occasional random transmissions when the sun wakes up it's solar panels, there is a risk it will interfere with other missions. So the standard protocol is to switch them off.
Einion Yrth said:
It's on the surface of a comet that is now rapidly heading off towards the cold bits of the solar system; why does it matter whether it's turned off or not?
Its radio transmissions could interfere with future space probe transmissions.But its transmissions would be going to nobody as once on the surface, the transmitter dish is not aimed directly at earth - so it would be transmitting to no purpose.
It was considered best to shut it down.
I do think these people know what they are doing.
ash73 said:
Yes but you don't need to be in contact with it to switch it off, you can program it to switch itself off.
Rosetta's final image was a blurry mess
That's exactly how it was turned off. It was programmed to switch off at the moment it made contact with the surface. It's hundreds of millions of miles away. Because of the time lag in sending instructions to the craft, the only way to ensure it turned off was to programme in the instruction in advance.Rosetta's final image was a blurry mess
ash73 said:
Yes but you don't need to be in contact with it to switch it off, you can program it to switch itself off.
Rosetta's final image was a blurry mess
That's as expected though. Rosetta was never intended to land on the comet so the camera wasn't able to focus at that range.Rosetta's final image was a blurry mess
Speaking of which, the photography has been a crucial part of what made this mission so popular with the public I think. That first shot of the comet is one of my favourite photographs of all time.
If future missions are to get public support they really should consider the part photography has played in the Rosetta mission.
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