Mars Rovers Return to Exploration 145
inkslinger77 writes "The two Mars rovers that have been carefully conserving critical power supplies since June, when the summer dust-storm season began on the red planet, are now springing back to work as the storms subside.
Typically, the solar panels on each rover produce about 700 watt-hours of electricity per day — enough to light a 100-watt bulb for seven hours, according to NASA. But this year's dust storms reduced that to as little as 128 watt hours per day. When daily power generation is down to less than 400 watt-hours, the rovers suspend their driving on the planet and stop using their robotic arms, cameras and other instruments.
But they are back in action now!"
Sadly (Score:2, Funny)
Batteries (Score:5, Funny)
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Actually, the little rovers could use the extra heat...
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When asked if the Rover was concerned about having lion batteries, it replied: "Hakuna Matata"
Author Shill (Score:5, Interesting)
inkslinger77
narramissic
jcatcw
If it's all OK and everything with the corporate ownership of Slashdot to be played by IDG, I suppose that's their business, but one would hope that they are actually getting PAID for being part of IDG's advertising program. And of course there should be disclosure so that visitors to Slashdot realize they are reading advertisements and not an article submitted by a "real" user...
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I don't think you need NASA to say that (Score:5, Funny)
I don't think you need NASA to say that - I think I can confirm that 700 watt-hours will power a 100-watt bulb (or device) for 7 hours. furthermore, improving on NASA, I can also say that it will power 7 100-watt bulbs for 1 hour, or 1 700-watt bulb for an hour.
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like "Only old people in Korea use e-mail... according to NASA"
Re:I don't think you need NASA to say that (Score:4, Funny)
Re:I don't think you need NASA to say that (Score:5, Funny)
I think you meant under 20,000.
Re:I don't think you need NASA to say that (Score:4, Funny)
Re:I don't think you need NASA to say that (Score:5, Funny)
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Re:I don't think you need NASA to say that (Score:5, Funny)
Re:I don't think you need NASA to say that (Score:5, Funny)
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Re:I don't think you need NASA to say that (Score:4, Funny)
Re:I don't think you need NASA to say that (Score:5, Funny)
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Get off my lawn, you damn kids!
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We're not old. We're well-read.
I'll say (Score:2)
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Wait, under 3000.
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I think you meant under 10,000.
I wonder if there's a market for selling low UID accounts.
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Re: I don't think you need NASA to say that (Score:5, Funny)
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Going one further than NASA (Score:2)
Who would have guessed?
Crazy units (Score:3, Interesting)
Since a watt is just a short way of saying one joule per second, this means
700 joules per second per hour per day
Do NASA really do their energy computations in this unit? Given their past problems getting to grips with the metric system, perhaps they might.
Surely it would be clearer to say 'the rover's solar panels have an average power output of about 29 watts'. Anyone could see that this is enough power to run a 100 watt lightbulb nearly one-third of the time.
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[1] No, it's not really power in the physics sense, it's energy.
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> 700 joules per second per hour per day
No, 700 joules per second times hours. i.e. energy per time multiplied by time = energy
A watt-hour is a unit of energy just a a joule is, except its a bit clearer how it relates to other quantities.
And calculating average outputs over a time period where the out put fluctuates wildly is a bit silly.
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Yeah, but how many watt-hours per hour?
(Btw, as others pointed out, I think you meant 700 "joule-hours per second-day" or "joules per second per (day per hour)" or "(joules per second)-(hours per days)es". Recurring isometric units are fun!)
Putting things in useful units is important. But a the same time, some people have bizarre views on what consitutes useful. For example, in fractions relat
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Besides, the image of California getting a big pile of pennies and assorted change every time someone sends a dollar to the Feds just seems sort of warm and happy. Ahh, change. Can ya spare some?
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The rovers' solar panels only generate power during daylight, and even then the generated power varies continuously as the sun angle changes. So talking about average power production produces a misleading picture of how the power is actually delivered; in many ways, it's more useful to think about some number of watt hours being accumulated per day as a lump sum, with nights separating th
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Next? (Score:2)
Re:Next? (Score:4, Informative)
Not "Defective by Design" (Score:3, Interesting)
Re:Next? (Score:5, Insightful)
Are you kidding? These rovers are functioning way beyond their mission parameters. They've collected more data than anyone expected. We've gone from "What if there's water on Mars" to "How much water is there on Mars?". The rovers survived a Martian dust storm! Martian dust storms have been known to cover the entire planet.
Let's put it this way. If your car was as well-designed and resilient as these rovers it would run on empty for 100 miles, drive up mountains, and review your tax returns.
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Easy. Just send 'em over to us down here in Gloucestershire [imdb.com]. They'll be up on blocks & covered buried in empty White Lightning bottles before you can say "Mossbauer Spectrometer".
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Mars Rovers Budget (Score:4, Interesting)
NASA's budget for 2007 provides $85 million for rover operations, communications, and data processing. Obviously that's a non-trivial amount (roughly enough to employ 350 people full-time, standard cost ratios), even compared to the $820 million spent on designing, building, launching, and operating for the first year.
For comparision, Hubble is receiving $340 million this year. The entire NASA budget for Mars exploration for 2007 is about $700 million. Almost half of that goes towards building the 2009 Mars Science Laboratory rover. The rest is divided between the Spirit and Opportunity, Mars Global Surveyor (which died a couple months ago), Mars Odyssey (orbiter), Mars Reconnaissance Orbiter, the US contributions to Mars Express (orbiter), Phoenix Polar Lander (lander, en route), and a Scout-class mission scheduled for 2011.
* My numbers came from NASA's 2007 budget request. Some of them were changed for the actual allocation.
700 watt hours per day? (Score:1)
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It runs and runs and runs... (Score:5, Informative)
It runs and runs and runs...
The dust storm even kind of polished [nasa.gov] it.
Go rover go!
What this really says... (Score:2)
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Re:It runs and runs and runs... (Score:5, Interesting)
The untold story of the MER rovers is the triumphant vindication of Steve Squyres' then unprecedented decision to allow the raw imagery to be automatically thrown up on the net virtually as they came in - so that in some cases, the amateur mosaics, panoramas and other post-processed images were sometimes out before the official JPL team had even seen the raw data. Indeed someone even wrote an application [blogspot.com] specifically to pull down, process and render the raw data. (Yeah, it's GPL'd :) )
Since it seems to come up every time (Score:5, Informative)
The issue of whether or not to put some sort of dust-clearing device on the panels was examined critically and decided on early in this project. In short: they didn't know what dust storms would do to the panels; it turns out they tend to remove dust. Several options for dust clearing were considered -- wipers, electrostatic techniques, peel-away plastic, and probably others I've forgotten. All of them would have *probably* worked, and all of them would have taken up space and weight. Essentially it came down to choosing between dust removal and an instrument. Faced with that decision, they decided that better quality, more complete data was more interesting than having the rovers run longer.
Of course, they got lucky, and the dust storms seem to clear dust off the panels. So there was even less need for dust-clearing than they thought there might be.
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was anybody running a book? (Score:1)
Spirit and Opportunity, I salute you!
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Amazing (Score:1)
Re:Amazing (Score:4, Insightful)
If mankind ever makes it to Mars in the flesh, I hope they bring one back and give it a medal or something.
Maybe mount a plaque at the point where it 'died' on Mars as well.
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Maybe mount a plaque at the point where it 'died' on Mars as well.
At this rate, it's more likely that one of the rovers will end up filming the landing for us to watch.
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Ass-covering (Score:1)
Built NASA Tough (Score:3, Informative)
mars solar time (Score:5, Informative)
Anyway, for those similarly bemused and/or further intrigued, here is the explanation of Mars Solar Time as Adopted by the Mars24 Sunclock [nasa.gov]
Design... (Score:1)
Not descriptive enough (Score:5, Funny)
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700 watt hours. That's enough to run your Gaming PC for 6.5 minutes, or light 42,338 super bright white LED's at 125% brightness for 1 second in a blindingly bright flash that will make everyone for miles say "WOW! THAT WAS BRIGHT!"
Software Never Dies (Score:4, Interesting)
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And war played a huge part in medical advancements, used daily in our lives. That doesn't mean war is good. Come on...there are reasons you don't see people scrambling to do new coding and project development in COBOL.
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I was fixing it because the original programmer -- and I am NOT making this up -- committed suicide. Hmmmm...I wonder if there is a connection?
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Huhhh? interpreted Cobol? I haven't seen a Cobol interpreter since I worked on a SuperPet back in the dark ages?
BTW the SuperPet was a great system for schools. I had Pascal, Fortran, Cobol, APL, Basic, and an Assembler. What was best of all the where all interpreters with the possible exception of the Assembler.
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"700 watt-hours of electricity per day" (Score:2, Interesting)
Do you really have to be a rocket scientist to figure that out?
Q: Why do NASA engineers buy their shoes much too big?
A: They think their feet are one meter long.
100 watt light bulb for 7 hours (Score:2)
More information (Score:2, Funny)
Radioisotope thermoelectric generator (Score:2)
http://en.wikipedia.org/wiki/Mars_Exploration_Rove r#Power_and_electronic_systems [wikipedia.org]
http://en.wikipedia.org/wiki/Mars_Science_Laborato ry#Power_source [wikipedia.org]
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The less than sign threw off parsing. The link leads to a table of RTGs used. Yes, Galileo had two RTGs.
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And at least we aren't to the point of saying how many angels can dance on a rover's solar panel, or somesuch. Yet.
Re:Can we please not dumb this site down? (Score:4, Funny)
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Nothing special in making up these type of calculations. For all-integer solutions, all you need to do is get the factors of the base number (700 Watts), which in this case are "2, 2, 5, 5, 7", then put these numbers in an equation of the form "A (count) B (wattage) Bulbs for C (time) hours". Replace A, B, and C with permutations of the factors multiplied together.
If you don't understand that, then just randomly choose A and B, and calculate C using "C = 700 /
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