They only bloody did it... (ESA content)

[kerryxeg]

I was reading a website with the details today. How do you catch and land on something doing 40000mph. They started the planning 25 years ago. They list all the objectives etc which don't really translate to me at least, but they should basically improve our understanding of how planets were created. Very impressive so far and much more to go if they get the data they are after.

[graeme]

Rosetta continues to orbit 67P. When it's on the dark side and out of contact from Philae, Rosetta emits RF and measures the reflection from the surface, while Philae measures the absorption that passes right through the comet. Working together, they can capture reflection and absorption data simultaneously which tells much more about the comet's composition than either would on its own. When Rosetta appears back over the horizon, Philae uploads data to Rosetta for relaying back home. Everything... is just... wow!

[tut]

Simple one is that if they find water there that matches the composition of our own, then that is very likely to be our source from four billion years ago.

tut

[robin]

Tut, I suspect each slingshot would have been tweaked rather than pre-programmed - there are many unpredictable factors that affect an object's trajectory in the solar system (solar activity, for one).

Given that the system is useless without comms, it only needs enough autonomy to be able to complete manoeuvres that cannot be done round trip; when Rosetta is relatively near earth (almost all the time when doing slingshots) it would have been within a couple of light-minutes and so plenty of time to make correction, analyse new trajectory, make follow on correction.

I have no idea how they actually did it, by the way, but I doubt it was pre-programmed from launch.

Cheers,
Robin

[Ferg]

Old Albert's special theory of relativity would be central to napping the course. But yes, there must have been adjustment points built in.

Still astonished each time I think about it.

[tut]

As you may have gathered by now I am fascinated by space, the Universe, and our place in it. I also believe that physically we are constrained to our own Solar System, the limitation imposed by the speed of light means that although we can look beyond to the past, we are never going to be able to physically visit and see for ourselves.

Likewise if there are any other civilisations/aliens out there we will never be aware of them as they have the same limitations. Not even getting into FTL drives or wormholes, they are just wish full thinking and speculation.

tut