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Mars rover camera project manager explains 2MP camera choice

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Re: Mars rover camera project manager explains 2MP camera choice

#51

Post by arrrg »

mturmon wrote: post #50
arrrg wrote: post #18

Earlier quoted context omitted.

Last minute changes are made. Or at the very least I know of one such change in the case of Curiosity. The dust covers over the haz cams (the navigation cameras on the belly of Curiosity) were added in the last minute. Here is the engineer who implemented them writing about the covers: http://forum.nasaspaceflight.com/index.php?topic=29612.msg93... Basically, the Phoenix lander (landed on May 25th 2008) kicked up mor…

It's all about risk. It's not about "leftover money". Cost, schedule, risk. They are the fundamental resources for a project like this. Cost and schedule are more familiar than risk.

So if it’s about cost it’s about leftover money. That’s one and the same. (One just doesn’t sound as professional as the other.)

Re: Mars rover camera project manager explains 2MP camera choice

#52

Post by waterlesscloud »

brudgers wrote: post #47
hugs wrote: post #41

Earlier quoted context omitted.

The lack of an on-board microphone could/should do that, too. :-) Pictures are a great, but a full-30fps video (with audio!) would greatly enhance our feeling of what it's like to be on the surface there.

Mars has a very thin atmosphere, so a microphone would capture very little data if any. Star Wars aside, there isn't much sound in the universe.

Mars is also windy, and microphones can be made to be very sensitive. Plus, there might be some interest in hearing the dust from one of the common dust storms hitting the rover.

Not a high priority in terms of data, but potentially interesting nonetheless.

Re: Mars rover camera project manager explains 2MP camera choice

#53

Post by mturmon »

qw wrote: post #36
cstross wrote: post #24

Earlier quoted context omitted.

You didn't read the article, did you? The entire mission can return around 250 mbits of data per day to Earth, because it's on Fricking Mars! Going to a 4MP camera CCD was considered and rejected because it'd result in slower image capture during time-sensitive processes (such as the descent cam) and gobble down far more of that valuable bandwidth which is shared among all Curiosity's instruments. Going to a 4MP came…

I can understand their choice of a tested technology, but I don't understand the bandwidth argument. Is the processor so underpowered that it couldn't crop the image when needed?

Scientists have historically been very skeptical about automated region-of-interest cropping, or fancy novelty-detection methods, or even certain kinds of compression. They are always afraid that something of importance will be filtered out. It's a difficult argument to win.

Prioritized downlink is accepted (you still get everything, but there's some automation that finds the most interesting stuff and sends it first).

There's even experimental acceptance of planning/machine vision systems that choose targets opportunistically while a rover is moving from point A to point B.

That is, points A and B were chosen by science planners. But while the robot is moving from A to B, it looks at stuff and stops en route to collect more data if it sees something interesting. You can sell this to scientists because they still get the data from points A and B (they're in control) but they also get more data from in-between, that might be interesting, and that they would not get otherwise.

This has been used on Opportunity and won the NASA software of the year award last year (http://www.jpl.nasa.gov/news/news.cfm?release=2011-380). It's a harder problem than it sounds like, because the robot has to re-plan its activities on-the-fly ("plan" in the sense of moving cameras, turning the robot, etc.)

Re: Mars rover camera project manager explains 2MP camera choice

#55

Post by mturmon »

arrrg wrote: post #51
mturmon wrote: post #50

Earlier quoted context omitted.

It's all about risk. It's not about "leftover money". Cost, schedule, risk. They are the fundamental resources for a project like this. Cost and schedule are more familiar than risk.

So if it’s about cost it’s about leftover money. That’s one and the same. (One just doesn’t sound as professional as the other.)

You offered two possible explanations for the use of a 2MP camera, (a) money, (b) risk. I was saying that, in this case, it did not really have to do with money.

My second sentence above was trying to point out that many people underestimate how important risk is to a space mission.

Re: Mars rover camera project manager explains 2MP camera choice

#56

Post by kbolino »

smackfu wrote: post #34
krschultz wrote: post #7

Earlier quoted context omitted.

For perspective, a single nut or bolt often costs hundreds to thousands of dollars by the time you are done with the Mil Spec qualification. You are off by a factor of at least 3, likely 4 or 5.

Of course, once you stop seeing this is as crazy, you are doomed to mediocre results.

No, it would be crazy if the rover failed due to a bad bolt, and no one could explain why the bolt was bad or even where it came from.

Also, no one is stopping you from building, launching, landing, and operating a multi-purpose roving vehicle on the surface of a foreign planet, 50 to 400 million kilometers away, that's designed to last for several years and withstand extremes of temperature, pressure, and radiation.

If you can do better...

Re: Mars rover camera project manager explains 2MP camera choice

#57

Post by arrrg »

mturmon wrote: post #55
arrrg wrote: post #51

Earlier quoted context omitted.

So if it’s about cost it’s about leftover money. That’s one and the same. (One just doesn’t sound as professional as the other.)

You offered two possible explanations for the use of a 2MP camera, (a) money, (b) risk. I was saying that, in this case, it did not really have to do with money. My second sentence above was trying to point out that many people underestimate how important risk is to a space mission.

Oh, no, I wasn’t claiming that this change had anything to do with money. In this case it was clearly related to risk. I was just trying to make a general point.

Re: Mars rover camera project manager explains 2MP camera choice

#58

Post by darien »

officemonkey wrote: post #19
ericcholis wrote: post #13

2004 technology aside, this is called the "Good Enough Factor". Obviously every super geek at NASA wants an 20 MP camera with full zoom,100 year lifetime, 3d, blah blah blah. But, they are working in very exact specifications and budget. So, you have to opt for the option that satisfies the Good Enough Factor. What will get us closest to what we actually want, without totally breaking spec and screwing with the time…

Maybe NASA will do a Kickstarter project for their next rover. :-)

I see it now. Pledge 1 million dollars (1 of 5 left)and be invited to NASA command center during Rover touchdown. Plus all of the above.

Re: Mars rover camera project manager explains 2MP camera choice

#59

Post by kghose »

johno215 wrote: post #35
kghose wrote: post #32

I really liked the article - it was very coherent and easy to follow. BTW, is there a full-res movie of the descent? I've only seen the 'thumbnails' stitched together of the heat-shield and the parachute.

Not yet. Only 20 or so of the full frames of the descent have been downloaded so far. Will probably be a day or more before they are all down. You can see the frames that are down here: http://mars.jpl.nasa.gov/msl/multimedia/raw/?s=0

Thanks for the pointer. This really brought home to me the 'baud rate' issue of interplanetary communication.

Right now, I'm so used to streaming movies at home that I forget the challenges of communications across such vast distances .

Perhaps our children/grand-children will be using the faster interplanetary internet and will recall these days with the same whimsy as we do now our twisted-pair modem days.

Re: Mars rover camera project manager explains 2MP camera choice

#60

Post by kronusaturn »

sigkill wrote: post #43

I'm a bit disappointed that they didn't take this as a chance to try out cobbling up a "radiation box" and put commercial equipment in that. Surely, that would be a good experiment data point that could be used in future endeavors.

It sounds like they already tried something like that on ISS, and the commercial cameras still had problems.
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