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Watch Out Mars: 1080 HD Video of Curiosity Descent (scientificamerican.com)
137 points by MetallicCloud 1611 days ago | hide | past | web | 25 comments | favorite

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.

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.

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.

> 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.

With that argument you could argue that any loss of money is unimportant, because it could have been used better. This amount has been invested for Mars exploration, so a mission failure would be a net loss.

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.

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.

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.

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.

Here you go this might help


A split screen view of the computer simulation with the original MARDI images synced up.

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...

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

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

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?

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.

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.

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 :)

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

Airbag has other issues too, like you might not land right side up, and you have to drive off the airbags / landing platform.

IIRC, one of the engineers said that material to make airbags strong enough to handle rover of this weight does not exist.

Also, they don't really want a solution that works up to the size of this rover. They want one that works for 5x or 10x the weight of this one, that could be used for manned missions. Curiosity is meant to be a test for that as part of the mission. Similar to how Mars Pathfinder was a science mission but also a test for the Mars Exploration Rovers.

From the press conferences I've watched there seems to be more debris on the rover than expected so its possible it wasn't as successful as they wanted. It could also just be that they landed in an area particularly prone to debris, I'll let the experts sort that out.

It´s a interesting problem though... I still find it mind boggling that they pulled of that landing sequence... It´s so much more complex than the airbag idea of the last landing.

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


I'm not sure if this is the answer, but 1080p is actually 2MP — 1920 * 1080 = 2073600.

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