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Mars Rovers Return to Exploration
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, with their relatively low speed, they will probably never find Sarah Connor in time for Fox's upcoming "The Sarah Connor Chronicles."
Hope they're not Li-ion.
They say the first thing to go is your penis. Well, it's either that or your brain. I forget which...
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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Would engineers and scientists wish these machines just die so that new, better explorers can be built and sent to Mars?
Virtual Betting on Facebook for non-geeks.
Sounds like a "Nobody would ever need more than 64k" kind of situation to me.
What?
It runs and runs and runs...
The dust storm even kind of polished it.
Go rover go!
"Hannibal's plans never work right. They just work." Amy/A-Team
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.
It says that America can do things, *when America puts it mind to it*!!!!
"You can't make a race horse of a pig"
"No," said Samuel, "but you can make very fast pig"
...because surely, they'd be annoyed with anybody choosing "three years or more" for million-to-one odds on the bet as to how long these rovers would last...
...and they just keep on going! I am fucking amazed at how overdesigned these thing are; broken wheels, mini tornadoes, planet-wide dust storms; nothing (so far) seems to be able to keep these machines down, and in some cases, theoretically adverse conditions are helping them to keep going!
Spirit and Opportunity, I salute you!
I think it's amazing that these rovers still keep going. Not that I doubt in engineering skills of people involved, but they "just keep on working", which I find pretty extraordinary. You'd think that any equipment left in such harsh conditions would turn into trash very soon. I was almost sure that at least one of them wouldn't survive the storms, but, fortunately, reality proved me wrong. Go NASA!
"We are the music makers, and we are the dreamers of dreams [...]."
Shame on me, but this is the first time I visited the mars rover website. It struck me as slightly odd that NASA researchers call the Martian Solar Day the sol.
Anyway, for those similarly bemused and/or further intrigued, here is the explanation of Mars Solar Time as Adopted by the Mars24 Sunclock
shooting is not too good for my enemies
And weren't these things inspired by designs from kids?
Fortunately they are not into consumer electronics. Otherwise there'd be a DRM on these rovers, one they would have retired 3 years ago in a cruel, wanton act of planned obsolescence.
Going one further than NASA, I can also reveal that the rover only ended up getting power equivalent to lighting one 100-watt bulb for 1.28 hours, or 128 1-watt bulbs for an hour, or one 1-watt bulb for 128 hours.
Who would have guessed?
700 watt-hours per day
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.
-- Ed Avis ed@membled.com
I actually think that the engineers who designed it had a pretty realistic view of how much punishment the rovers could handle, but if you get the same amount of money whether you say "We are sure it will work for X time" or "We are sure it will work for 5X time", why not go for the first? If something horrendous happens after 2X time, your ass is pretty much covered, and everyone will just say 'Wow! It had an operation time of twice the expected!" instead of "We're never gonna hire those yolks again, their shit didn't even work half the expected lifetime."
I know I'm oversimplifying, but I have no doubt that that's their M.O.
I grew up in a coal mining area of Illinois. The worlds largest shovel (Marion 6360) was in the mine where my dad worked...and it used the same crawlers that NASA made for the space shuttle. Down at NASA, they have the thing crawl out on a carefully leveled bed of pea gravel....but down in the mines, they had some mats to lay down, but the crawlers would still crunch over stuff. Apparently, when some of the NASA people came up to look at how the shovel was doing on their crawler system, they were utterly horrified at the conditions...not one of them thought it possible for the crawlers to perform in half so "bad" of conditions and still work for any amount of time. The crawlers worked all the way till the shovel burnt in the early 90's and the thing was scrapped (an oil fire hot enough to split open the inches thick steel skin of the sucker)...
Why are you describing to slashdotters, 700 watt-hours will light up a 100watt bulb for 7 hours? Is it that easily imaginable? Should use very precise engineering descriptions like, four football fields long or as big as a refrigerator or something. The most descriptive way to describe 700 watt-hours would be something like the energy spent by a senator tapping the restroom stall floor with foot over his entire three term career or the energy used by a /. mod marking 8324 posts as trolls, flamebaits and underrated.
sed -e 's/Chuck Norris/Rajnikant/g' joke > fact
We as software developers here should take note of this. The code you're writing and putting into production has the potential to last for decades. For example, out of college my first programming job was for Mutual of Omaha. They had lots of code that was written in the late 1960s in Assembler or in (gag) COBOL. Well, although someone like me would have loved to have rewritten those systems, it was not happening. Then, take another point. I myself wrote a large system for them that--according to friends who are still there--and that system has not been changed much since then. So, folks, the point is this: you write a lot of applications. Some won't survive a year. Others... they may be doing their job in twenty years. Machines wear out but--properly designed and maintained--software never does. Bravo to Spirit & Opportunity and the teams that built those kickass pieces of hardware/software.
Sigh. It's practically obligatory when you're talking about science (at least in the States, how about other countries?) to dumb it down. At least they didn't say how many ping-pong balls the rovers could carry if they were hollow.
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.
Hail Eris, full of mischief...
E pluribus sanguinem
"700 watt-hours of electricity per day -- enough to light a 100-watt bulb for seven hours, according to NASA"
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.
HA! I switched to CFLs, so I get light for 30 hours!
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...
If you want news from today, you have to come back tomorrow.
It thought that before the storm NASA was saying that these dust storms were likely to kill the rovers more then anything. I'm excited to see the rovers go as far as they have and further, but I'm thinking that maybe NASA just wanted to keep everyone's expectations low so we over joyed when it beats them. All in all, I'm really glad they are doing so well.
You keep showing up as being in the way-back machine as being before christ.
I prefer the "u" in honour as it seems to be missing these days.
> Past storms on Mars affected the rovers, but those were only short-term events, Matijevic said. This year's storms were especially strong.
Must be the global warming.
Slashdot is able to reproduce an article twice per week, that's close to a dupe in about 3 days, according to Nasa. http://science.slashdot.org/article.pl?sid=07/09/0 3/0154202
Why yes, they ARE Lithium Ion batteries.T _ID=252
http://solarsystem.nasa.gov/scitech/display.cfm?S
"The Mars Exploration Rover mission is the first major NASA planetary exploration mission to use the advanced lightweight rechargeable lithium-ion batteries, which are three to four times lighter than their nickel counterparts. In addition, the battery can last five times as long as the planned 90-day primary mission."
This is a concern, but NASA considers the work the rovers are doing valuable enough to keep funding it.
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.
I wondered whether a radioisotope thermoelectric generator (RTG) would have been a good choice. The batteries used weigh 7.15 kg to deliver about 100 W (1). RTGs in development to deliver about the same power weigh 34 kg and 2). These RTGs are being developed for the next generation rover, the Mars Science Laboratory.
e r#Power_and_electronic_systemso ry#Power_source
http://en.wikipedia.org/wiki/Mars_Exploration_Rov
http://en.wikipedia.org/wiki/Mars_Science_Laborat
If you added links to independently verifiable sources for your claims, (some) people might actually listen. Otherwise you are indistinguishable from the paranoid conspiracy nuts, at least until 911 scene 2 happens in a day or two...
Do as you would be done to.
If you think you're "enlightened", what if instead you were snowblind? Would you know the difference? How could you tell if your hate has programmed you? Do you use the word "NeoCon"?
Then yes.
The propoganda, handed out as "the straight truth" and "What Bush doesn't want you to know" has made you insane. Ever pick up history books? Ever pay attention to the news _before_ you were programmed?
I'm getting tired of hearing it.
--- For a good time mail uce@ftc.gov