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Mars Science Laboratory landing tonight


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Totally off-topic, but I think we can all relate to the enterprising spirit: NASA's Mars Science Laboratory mission is landing its rover, Curiosity, on the face of Mars tonight at around 05:31 UTC (in about 9:31 hours at the time of writing).

NASA TV will be broadcasting throughout the event.

Good luck, Curiosity!

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Curiosity is very interesting. Its the first rover to land via sky-crane and it also run on nuclear power :D So no ugly solar panels. Thanks for sharing dude (y)

I hope that included irony ;), well at least I think so...

totally off-topic, but are we starting a discussion about nuclear power?

Edited by Almin
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The big problem with getting back HD video (which we are going to get, eventually) is the bandwidth. HD images and video have a TON of information, and the earth is very very far away. Considering the limited size and power available for radio equipment, sometimes I'm surprised we get anything back at all!

The data is sent in binary, which is all 1s or 0s. Suppose the rover wanted to say "cat," it would send back "011000110110000101110100." The odds of one of those digits being received as the other is actually pretty high, so the rover sends everything in multiples. So instead of sending the above example, the rover would send "000011111111000000000000111111111110000111111110000000000000000111100001111111111110000111100000000" We just quadrupled our message size. Now if we get back a 0010, we know it's supposed to a 0. Consider the size of HD files, then remember we have to multiply it (not sure if it's quadruple, it's just what I'm using in my example. I think it's larger actually.) and THEN consider the limited power and size of the radio equipment and you can see why it'll take a long time to get back HD video. We gots TONS of data moving through a tiny interplanetary pipe :)

And just because the process isn't slow enough, sometimes entire packets are lost (instead of bits being flipped.) so each packet is further buffered with enough information to rebuild parts of other packets. In the end, the file we get at the end of the pipe is much smaller than the data that was transmitted.

Oh yeah, and let's not forget that like all planets, Mars rotates. This means that for days at a time, Curiosity is on the far side of the planet and we have no direct radio communication with it. We do have orbitals that help with this, but using them adds more time and overhead to the communications.

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IIRC, that's because all of the hardware needed to be radiation hardened. Instead of using normal RAMM for instance, it uses specialized magnetic core memory. (Stuff looks so cool.) Since this stuff is a very specialized product, there's not much incentive for a company to improve on it's design. Therefore, none of the stunning advancements in miniaturization that consumer electronics have had. It's a similar story for the rest of the computer hardware in there.

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  • 2 weeks later...

Really cool to see how "worn" it is :) Most other images I've seen have either been closeups or plain desert (which of course also is a sign of wear, but still not as obvious as this :) ).

Indeed. For a planet that's supposed to be dead, there's still a lot going on.

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