
Watch Out Mars: 1080 HD Video of Curiosity Descent - MetallicCloud
http://blogs.scientificamerican.com/life-unbounded/2012/08/22/watch-out-mars-1080-hd-video-of-curiosity-descent/
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InclinedPlane
This should give every coder a moment of pause.

Consider. Here we have a $2.5 billion interplanetary mission that is easily
the most ambitious space exploration mission since the Apollo project. And
it's using a completely new and untested landing system. Only bits and pieces
of the landing system have been physically tested, and not even remotely all
together. Because it turns out it is rather non-trivial to simulate an
atmospheric reentry from an interplanetary trajectory, in the Martian
atmosphere, under Martian gravity. In the end it came down to relying on our
prior understanding of the Martian environment and simulations and
measurements of the landing system and trusting the software to do its job.
Because the round-trip delay for a human to be able to effect some part of the
landing is nearly half an hour, and the entirety of the landing would take
about a quarter that much time. Indeed, by the time we on Earth would receive
a signal indicating that the atmospheric entry had begun in reality the entire
landing would have already occurred several minutes in the past.

If you ever thought that a lot was riding on your code, this will certainly
put that in perspective.

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m_for_monkey
This is nothing compared to medical software, for example. All you can lose
here is some money, but no human life in danger. Some more perspective.

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icambron
I disagree. 2.5 billion dollars is worth a lot of lives. Consider how many
people you could save from, say, malnutrition with that money. I don't know
the answer, but I'm pretty sure it's a lot. And we as a society have decided
that space exploration is actually _more important_ than saving those people.
Now, you can agree or disagree with society on that point, but either way, a
lot is riding on this, even measured in units of human life. If the thing
crashes into the ground, we wasted money we could have done something else
with. A lot of something.

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epo
I really hope you are joking. You really want to maintain this money was
diverted from being spent on tackling malnutrition? The US spending on Iraq
must really tick you off.

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icambron
Not joking. If you have 2.5 billion dollars, you can spend it on what you
want. Congress shifts money around all the time. They just want to spend it on
rovers.

Now, to be clear, I think there are plenty of good arguments that spending a
marginal 2.5 billion dollars to put a robot on Mars is actually the right
call, in terms of its long term benefits for humanity. Wasn't taking a
position on that either way. My point is just that you can measure the cost
(and, by assumption, benefits if we're successful) in units of human lives,
and that it's a big number. That's wiped out if the rover crashes, so a lot is
riding on that code.

You might argue that the risk of failure is priced into the tradeoff society
made. You might also argue that not all of the value of sending the rover is
destroyed if the landing fails. Those both seem uncompelling, but I haven't
thought too hard about it.

US spending on Iraq does, in fact, really tick me off. It's an enormously
inefficient use of resources.

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gcr
Apple's recent settlement of $1B puts this thought in another related
perspective.

Consider that we've lost over a third of an interplanetary mission in
pointless legal battles.

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dhughes
It's hard to get a sense of scale, one minute it's wow so high up look way
down at the craters then suddenly oh! That's not a crater that's the ground.

Beautiful I didn't know they had such high quality video I figured like it
seems on all the others missions data is kept to a minimum and we'd only see
black and white 640x480.

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mbell
I think some of this is that the video is sped up. Best I can recall from
being nerd-locked into the data coming back from MSL the decent camera only
captures 5 frames a second at this resolution. This video is obviously
replaying at a much higher frame rate so they are either playing it back at
faster than real time or they interpolated a lot of frames, I'm guessing the
former.

[EDIT] And now that I stop playing the video on repeat I realize this was
covered in the article and the video description...

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MetallicCloud
Yep, it's captured at 5fps, and played at 15fps. So it's running at 3x.

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dhughes
Ah, I missed that part, so I'm not crazy.

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thomasf1
The final drop is quite messy, there´s a lot of dust.

I wonder how happy NASA is with the sky-crane solution - would they do it
again as the new standard for mars rovers or is it in the "nice try" category?

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hartror
The dust & gravel situation was only one reason the sky-crane was used. The
other options of traditional lander or air bags have worse issues beyond dust
and gravel and in the case of a lander the dust and gravel issues are worse.

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sliverstorm
Really? I had heard the issue was Curiosity was to be heavier than past
probes, and they weren't confident the old airbag method could handle the
weight gently enough.

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pattern
Additionally, the "violently tumble while marginally protected by airbags"
plan isn't a viable method for eventually landing humans on Mars! One more
reason to come up with a "gentler" descent :)

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zrgiu_
actually, with a human on board you have other, less complicated options.
We've been using them for a while:
<http://en.wikipedia.org/wiki/Harrier_Jump_Jet>

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datalus
Wow, right before it touches down the camera just gets still and I get sucked
right into the video as it touches down. Otherworldly.

