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Posted
by
michael
from the look-both-ways-before-crossing-the-street dept.
Irishman writes "It looks like the Spirit rover has finally left the womb and is rolling free on the Martian surface. Space.com has the full story and some great pictures." NASA also has photos, straight from their fake set in Hollywood where they produce all the "space" footage.
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I've been really hoping that one day they'll go back to
the original Sojourner site and return that unit to Earth for
analysis by NASA. They could gain valuable information as to what
finally gave on that rover and use it to harden future
rovers.
Sojourner was a great success as it lasted
much longer than expected. Of course the cost of getting that unit
back to Earth would be so high I'm guessing these are just nice
dreams. C'est la vie.
The batteries can only recharge a certain number of times. Furthermore, there is no way of cleaning the solar panels, so they lose their efficiency over time. That's probably what contributed to its death and you're making a big deal out of a piece of crap rover.
Dumb question, why no wiper blades? I've heard it said that wiper blades would damage the solar panels. However if the solar panels are too dust covered to work anyways, what's the loss? It's not like they're going back for warranty repair.
Wild-ass guess, but the wiper mechanism would probably get jammed by dust just about the time if could be useful in cleaning off the solar cells.
Seriously, even the scientists on the project wanted an RTG in the thing. They could have driven it around for *years* if they had. Instead, they got solar panels which (due to dust) have an expected lifetime of about 1/2 a year. Stupid environmentalism...
Could you kindly define RTG? Is that some sort of reactor?
Radioisotope Thermal Generator
If you punch it into google, you'll find that it takes the heat from plutonium or strontium-90 and turns it into usable electricity. There are no moving parts and no fission or fusion reaction. It's just a lump of rock (actually metal) that gets very hot.
SRG stands for Stirling Radioisotope Generator
These are more efficient power sources that use the heat from radioisotopes to power a stirling engine (the precursor
My understanding is that this exact option was considered. The decision was that they could include an effective dust removal system, at the cost of any one of the instruments. They chose to keep the instruments.
Sheesh - the JPL guys ought to talk to some desert racers sometime. They deal with more dust in the course of a Baja 500 than most of us do in an entire lifetime.
Anyway, some simple low-risk ideas:
* A small air blower jet to blow the dust off. After all, there is an atmosphere (albeit a thin Martian one) to work with.
* Tilt the panels and give them a gentle shake to get most of the dust off.
* Use an electrostatic coating to keep the fine dust from sticking.
If they'd used an SRG or RTG they wouldn't have those problems. Solar cells? Bah. Waste of weight.
True, but dust and grit would eventually gum up most of the instruments and make wheels stick. The Viking landers didn't do much "moving" science after their first few months (after scooping soil, etc.) They mostly just tracked weather and looked around every now and then.
Making moving parts and instruments dust-resistant and/or cleanable would probably greatly add to the cost I would expect. In other words, power is only half the problem.
Further it costs something like 3 million USD a day to operate rovers (personell, communications, etc.) Thus, extended durations eat money in other ways.
And, it might be better science to have multiple short-distant rovers exploring a variety of marsographically[1] separated areas rather than one to two long-distance rovers. In other words, spend the money on quantity instead of duration.
And, "nuke" power cells are not politically popular due to possible launch crash risks.
And, "nuke" power cells are not politically popular due to possible launch crash risks.
While I generally agree with the rest of what you say, please don't call RTGs "nukes". They're simply heavy metals that emit some radiation and really don't post a threat to anyone. Heck, you've probably got similar materials in your backyard [cameco.com]. But we're *never* going to convince people otherwise if we don't stop calling them "nukes".
and there is a small chance that one could burst from launch errors...
The odds that one would burst are about as close to zero as they get. The RTG itself is sealed inside a "black box" type of shielding. The stuff is strong enough to survive reentry from orbit! An explosion of the rocket wouldn't even phase it (as past launch failures have shown).
...end up polluting a populated area.
Actually, that's why NASA launches over the ocean. If something does fail, it falls into an unpopulated area (i.e. miles of water).
I agree that the risk is tiny, but it does exist.
You have a greater chance of getting cancer from your cell phone battery.
Noboby sane claims they explode into mushroom clouds.
You'll love this guy [slashdot.org]. He still hasn't taken me up on my "nuclear challenge". I wonder why?;-)
And while we're at it, let's discuss the consequences as well. A one-in-a-million chance is small, but if it destroys the entire earth, it's probably too risky to offset almost any benefit.
*cough* *choke* *gag*
I can't believe I've got another one of you people [slashdot.org]. We're not even talking about a nuclear pile/reactor! We're talking about stuff similar to what's in your BACKYARD [cameco.com]!
Did you know that plutonium gives off Alpha radiation?
Did you know that Alpha radiation is not in any way shape or form dangerou
RTG's have been coming up alot on here lately, I should really save this and copy it...
RTG's are very, very, very safe. The poisonous gasses released by a rocket explosion are far worse than what an RTG can do. Here's why.
RTG's contain Plutonium 238, (an isotope which cannot be used in fissile weapons, its too unstable) that generate lots of heat which is how they work. Now a note about the safety of Pu238.
Plutonium is among the safest to handle radioactive elements. It only generates alpha particles
actually, they experimented with a windshield-wiper type devise, a sort of "roll-around" shield system and fans. Nothing seemed to be feasible enough to either work or survive the hundred-million-mile+ trip.
I think the problem with this is that it would require something that isn't just on a one-way trip ending in a crash landing on the planet's surface. That would require development of a new type of lander and something capable of carrying the full weight of the old lander.
I doubt that NASA has the funds or enough desire to go through all this to recover the craft.
It's not like Sojourner is going anywhere. I'm sure when we've mastered interplanetary flight to the point that it's just routine, we'll probably go back to all the left-behind probe carcasses to do some kind of forensic study and make monuments out of them for the tourists to see.
Getting back the old rovers/etc. would have no real scientific value
I think the point is that it would have engineering value. See exactly what worked better/worse than expected, then use that knowledge when building next vehicle.
Shame it'll be over so quickly, 90 days is predicted I think.
I've read that this mission is limited by the build up of dust on the rovers solar cells, reducing the power attained to the point where the rover can no longer function.
An obvious solution (to me, here in my comfy chair) would seem to be the ability of the rover to gently tilt and/or shake its panels to remove at least some of the dust.
Since the rover arrived with it's panels folded could it just fold and unfold them again to shake some of it off?
It seems such a pity for the mission to end for such a mundane reason since I presume it would otherwise continue until the batteries failed or physical wear/damage destroyed some key component.
Solutions for other missions spring to mind, perhaps: - blowing the dust away with a small directed jet of compressed air. - A small fan or brush on a simple arm. - Speciali(s|z)ed tilt/shake schemes (as above). - Raise the panels up on a windy day (without blowing over). - Layers of protective film that can be peeled away.
I wonder if there might be some way to build up a charge to clean them off? Shaking or tilting probably wouldn't work -- look at the crap that gets stuck on your car over time and it doesn't come off at over 100km/h.
I've read that some sort of solar panel wipers or brushes wouldn't work as they'd scratch the surface, allowing less light to reach it.
The plastic film idea reminds me of the removable visor strips racecar drivers have on their helmets. Sounds like a good one. Patent? Boo, hiss;-)
It's not because it gets stuck on there at 100km/h. In addition, martian winds have been known to exceed that, because there's so little atmosphere to get in its own way. It's because it gets stuck on with tree sap and burned oil, not to mention water. As far as we know there is no tree sap or burned oil floating around in the martian air, just dust and fines - the atmosphere is probably not thick enough to carry anything heavier than dust very far, though in a dust storm, I'm guessing there's more than jus
Wow! Good for you! You think like a NASA guy... I'm not sure of the specifics, but the missions principal scientist was my professor in college and he specifically said that they tried some of your exact ideas for the next rover (which was actually a cancelled 2003 mission). They tried a windshield-wiper type deal, layers of plastic film that would roll off every few days (think like a doctor's office, how they tear off that butcher paper and roll a new cover over for each new patient).
He didn't delve too much into specifics, but he definately said that they simply didn't get any of these ideas to work. Actually, there was a brief period of time when they were actually close to getting RTGs to power the rovers (plutonium, like the ones used in the Viking landers that allowed them to operate for 5 years), but the Greens stopped that:(
Right now Martian summer is slowly becoming Martian winter, and Mars is moving away from the sun (its orbital eccentricity is higher than earth's and has a major effect on Mars' climate).
So the solar cells will provide less power due to the lower sun angle and brightness, even without any dust accumulation.
Assuming no major mishaps, what will eventually kill the rover is lack of power to heat the electronics at night. Electrical components don't last very long unprotected from the wild temperature swings
There is also information from SpaceFlightNow [spaceflightnow.com] here [spaceflightnow.com] and here [spaceflightnow.com].
Here's a photo [spaceflightnow.com] of the landing platform it just rolled off of.
From the cited article: 'Data from the Spirit rover shows it completed this morning's drive off the lander at 3:41 a.m. EST. Confirmation was received on Earth just before 5 a.m. EST, verifying that Spirit had performed the 10-foot voyage on its own.
The move took approximately 78 seconds, ending with the back of the rover about 2.6 feet away from the lander egress ramp, officials report.
"It's as if we get to drive a nice sports car, but in the end we're just the valets who bring it around to the front and give the keys to the science team," says flight director Chris Lewicki.'
JPL engineers played Baha Men's "Who Let the Dogs Out" in the control room as they watched new images confirming that the Mars Exploration Rover Spirit successfully rolled off its lander platform early Thursday morning.
Oh for the love of... Really, we didn't need to hear this. I hope that didn't get caught on film because that's the sort of thing that resurfaces at retirement parties.;p
Oh for the love of... Really, we didn't need to hear this.
According to an NPR report this morning, they played the theme from Rawhide (Rollin' rollin' rollin'...) as they sent instructions for the rover to leave the platform.
I tell you what, those rocket scientists have one seriously inverted sense of humor sometimes.
After approximately 25 sols Beagle 2 will go into it's final communication mode SHM1 (Spell Help Mode 1). In this mode it will shred it's own parachute and lay the pieces out across the martian surface to spell the world "HELP".
Calculations suggest that each letter will be approximately 4-6 pixels across, easily discernable from the Mars Express orbiter.
High winds may hamper this last ditch attempt for Beagle 2 to communicate.
(I'm allowed to laugh, some of my tax money is spread all over the red planet)
About what might happen should the Martian government get their hands on the rover. They will most likely have to destroy it to cover up the fact that their planet has been visited by machines from another planet. Let's just hope we can get a picture of their leaders before they disconnect the cameras!
Let's just hope we can get a picture of their leaders before they disconnect the cameras!
what leaders? We will just see some poor homeless martians toying with the machine until they accidentally destroy the cameras. Then a one who is smarter will try to sell it for food.
if they are going to do mars and the moon they will need a moon set and a mars one - mind you they could use the same one if they expanded it a bit and different filters on the camera so long as they just never filmed the 2 things at the same time. Better yet use identical rovers/landing equipment in both places - 'to save money' then they could just timeshare.
Mind you area 5 is surrounded by lots of nice desert - rip out the sagebrush and only film at night (everyone knows it's always night on the moon,
I understand that the mission controllers wanted to take their time and not make any foolish mistakes, a policy I agree with.
However, I don't understand why they kept saying that moving the rover off the lander was "dangerous". I thought the rover was designed to be able to deploy even if the lander came to rest upside down. Instead it was right-side-up on level ground. The rover had to drive over the deflated balloon, but why was that more dangerous than just driving over the surface?
The rover had to drive over the deflated balloon, but why was that more dangerous than just driving over the surface?
Because mission engineers had tested the same setup (airbag position, rover position) and found that the orignal exit ramp had a chance that the rover's solar panel would get caught on the airbag. They decided to opt for the safest route, and turned the rover around and out through the second exit ramp.
Spaceflightnow.com has all the details. [spaceflightnow.com]
However, I don't understand why they kept saying that moving the rover off the lander was "dangerous"...
but why was that more dangerous than just driving over the surface?
I don't recall them saying it was more dangerous. I think they just said that it was dangerous.
I, for one, would consider almost any maneuver by the rover to be dangerous. After all, this is the first time those components have experienced leaving the Earth's atmosphere, existing in Mars' atmosphere, and everything in between.
* Driving over the balloons is more dangerous than martian terrain. They could get caught in the wheels.
* Suppose some part of the rover had been broken on landing, but had not surfaced yet because it had not moved. Think of a broken neck - it doesn't cause paralysis until you move and sever your nerves.
* Take advantage of a controlled situation. They wanted to take advantage of a controlled situation for as long as they could. From the lander they could take panoramic pictures from a sligh elevation. They could atmospheric measurements, etc. All this could be done without the adding the possible failure points introduced by moving the rover.
* The lander has more solar panels and perhapse some better communication hardware. Might as well take advantage of them while you're there.
I just pulled those off the top of my head. I'm sure there are better reasons and it's been discussed here before. Will you people stop bickering about them taking too long to move it?
How's this: Give me 3 equally good reasons why they should have hurried to get it off the lander.
Just to clarify: landing upside-down wasn't a failure mode because the lander could right itself by "flipping over" during deployment. This only gets the assembly into the right position for letting the rover roll off. This, as we've seen, is a whole different proposition.
Spirit actually had to roll off a 4-5" drop at the bottom of the ramp, possibly because of rocks, uneven ground, etc. That drop would've flipped Sojourner, for example, on its back. Being the size of a golf cart, Spirit has some advan
Just to clarify: landing upside-down wasn't a failure mode because the lander could right itself by "flipping over" during deployment.
That's what I like to see: a practical use for Robot Wars technology:-) Does it also have a big spinning disk and a wedge design for upending other robo^H^H^H^H Martia... oh, never mind!
The airbags were designed to deflate in sequence so if the lander came to rest wrong way up after its bouncedown it could right itself before opening up to reveal the rover. If the lander got stuck upside down, like in a crevasse, then there would be no way of deploying.
The sequence of activities to ready the rover for movement off the lander were the most complex series of steps ever undertaken by a space probe. Dozens of small pyrotechnic devices had to be fired to release clamps, sever cables and so on.
So if these space photos are made on a set (or out in a desert), where would all that money that Bush just announced he's giving NASA go? In my opinion, NASA should forget cameras and go for full-on fraudulent Mars cinematography. Complete with a full cast of Martian characters, leading up to a climax where the main character has to make a decision about whether his best friend lives... or DIES. *cue the tear*
Well I am glad to see that the thing did not get stuck on a balloon.
The chance of spirit getting stuck made me think. (For the next ones we make) Why not get some very small solid rocket engines and put them facing in all directions on this thing. If the rover gets stuck, then as a last resort they could try igniting one or more of these small rockets engines to try and dislodge the rover. These rocket engines would probably be the smallest model rocket engines (or smaller) since I would hope you wouldn't need much of a bang to move in the Martian gravity. They are also pretty cheap.
granted you'd only get one shot, but if it's a last resort it's better to have one shot then none.
"...since I would hope you wouldn't need much of a bang to move in the Martian gravity."
That only counts if you're going up, i.e. pulling against the gravity of the planet. The mass of everything involved is still the same, and that governs the amount of force you need to move against inertia.
So if you need to push the rover around, you'll need similar-sized forces (i.e. engines) that you'd need on Earth*.
(*) For the pedants: OK, the atmosphere is thinner, and the lack of gravity would reduce friction
Why not get some very small solid rocket engines and put them facing in all directions on this thing.
A common reaction to the realization of a vulnerability is to add complexity to address the vulnerability. This is often a bankrupt strategy.
Wouldn't you feel silly if the "next ones" incorporated exactly this suggestion, and were unusable upon landing because "a small rocket engine, included to address the possibility of a rover getting stuck, ignited on re-entry and destroyed several critical components..."
On projects like this, every gram of hardware costs pounds of fuel, every contingincy plan requires man-weeks of meetings, and every non-essential task added to the process list amounts to a lost opportunity for a once-in-a-lifetime experiment. The last thing you want is find youself facing actual mission failure because of some contingency you put in place to address a possible mission failure.
Did you look at those pictures? You can see the curve of it's surface from the surface. I dunno, I don't think life could have existed on a planet that small.
I found this [nasa.gov] to be one of the more interesting links from the NASA site. It is about a watchmaker in California who modified mechanical watches to keep Mars time.
JPL engineers played Baha Men's "Who Let the Dogs Out" in the control room as they watched new images confirming that the Mars Exploration Rover Spirit successfully rolled off its lander platform early Thursday morning.
A bunch of sweaty scientists dancing around the lab to "who let the dogs out"? Was Steve Ballmer there?
I think they should hurry up and do a close-up analysis of a rock rather than worry about long-distance jaunts. If it croaks in a few days, not having analyzed a single rock up close would be a shame.
Heck, you can download the software [telascience.org] yourself and drive a virtual version of the rover. For Windows, Linux, Solaris, and even Mac I think. And you can download actual photos/data from Spirit and have external 3d views.
You can even download via Bittorrent...those JPL guys are so nerdy it's great.
I downloaded and skimmed the manual but haven't tried it myself yet, but from the manual it's apparent you can view your rover in 3rd-person 3D.
The dirt sticking to the wheels of Sojourner (Pathfinder) was discussed at great lengths on a board I read [anomalies.net] (bit of a crazy board full of the insane for the most part, but there are decent threads from time to time), a bunch of people yelling "it's mud, Mars is wet!" when in reality Soujourner had spun it's wheels in the dirt and essentially "dug" in the dirt... Well, that and the "dirt" is largely magnetite which is inherently magnetic.
Flash forward to today and we've got the "magic carpet", and dirt sticking to Spirit's wheels, sans digging - very interesting, and by the sounds of it also very unexpected. It will be great to find out what's making it stick, and just "how Mars works" in general.
Did I ever mention how glad I am humanity has another rover on an alien world?:)
The sticking is likely because gravity is about 1/2 that of earths. Fine particles will cling much sooner in lower gravity when electrostatically charged. The martian world is probably covered in very very fine dust as the grains on the surface are blown around constantly grinding into ever finer particles. The lack of water would also mean the particles keep on the surface, when on earth they get washed into the ground much more easily.
Extremly fine dusts will act similar to this depending on the type of
They've really stumbled onto something interesting. The martian soil in this area appears to have a really strange consistency... they've talked about it before, it looks like mud...
I hope it doesn't get stuck, it'd suck to have to call a tow truck (or a martian redneck with a winch) to get it out:)
The best site for Spirit pictures (and Opportunity when it lands too, I'm sure) is JPL's MER site [nasa.gov], it's the official site, so first with the pictures (and if you click one of the dated releases and change the date in the URL manually you can sometimes get a sneak peek at the days release half an hour earlier than the rest of the world - about 4:30pm GMT or thereabouts:)
In the short run: Footage of that first step onto the Martian surface for the current president to use in a campaign commercial.
In the medium run: Footage of that first step onto the Martian surface for crazed conspiracy theorists to pour over, looking for proof it was filmed in the Gobi Desert.
In the long run: Footage of that first step onto the Martian surface for MTV to repurpose.
(This is a funny post, but I could write a serious one too, but I'm also sure someone else will. Whether the someone else w
Uh... to gain insight on how we can live on other planets. Life on earth is doomed, but it just won't happen (sun expanding) for a long long time. Take into account the chance of life extinguishing asteriods hitting earth, and I'd think that people would want to ensure the survivability of the species.
Face it, the earth is fragile and life on it only temporary until we figure out how to live without it.
Not to mention that humans doing experiments on mars GREATLY reduces the latency. How long does a round trip signal take? I could go on and on about why we want humans on mars.
Thank you for the toy RC car. To think, it only took you 4.55 billion of your years to get it to us! However, now that you have proven yourselves almost capable of inter-planetary traveling, we must send our Biker Mice to crush you like the bugs you are. Starting with Tim Burton.
Signed,
Supreme Commander of Mars
They should have named the rover "Egg", then we could have headlines such as, "Egg Rolls On Mars!" People would glance that and say, "It *is* true: you can buy Chinese food ANYWHERE."
Oh My *Deity*, im watching this guy give a talk on NasaTV (Nasa Update) He has been talking nonsense for at least half an hour and his audience look bored to tears !
Why does this thing have a "backwards looking hazard identification camera"? Are they that confident about finding life on Mars that they expect to be fleeing from it?
That's funny - a radio guy this morning was going on about how they might find the real killer on Mars since they are never going to find him here on earth.
it's jackass commentary like this that does nothing but perpeptuate bullshit to the masses and misinforms that average (read stupid) american. then the average (read stupid again) american's think these things are a waste of money.
Right, and how many "average Americans" do you know who (A) read Slashdot and (B) won't pick up the sarcasm in the original statement?
It's humor (though I'll agree, it's not really funny). Don't sweat it.
Unfortunately there isn't a launcher in the world big enough to get your design to Mars. Extraterrestrial robots are a nice balance of what people would like and what is actually feasible. This is extremely difficult to do, which is why it takes genius engineers to design them.
If you could do all of that, and deliver a package with the neccesary weight, size, and other various launch/flight/deployment constraints.. then you would be (by far) the best robot designer on the planet. Ohh ya, and be able to do all of those things reliably on an alien world millions of miles away.
These are smart people (I've had the privilige of working with two of them), that are well aware of all of those possibilities. The realities of design have to come into play at some point, and that's how these things really come about.
F) It has a GIANT SPRING, to pogo itself away from any Little Green Men if they come near it.
G) In the event of Giant Spring failure, the last resort is the Plasma Cannon.
H) In the event the Plasma Cannon initiates full scale interplantary war, it activates the Omega 13 device, reverses time, and destroys itself before it deploys the Plasma Cannon.
I) In the event of the Time Reversal Self Destruction Manuevor still incurring the Martian overlord's wrath, it sends a signal to me, so that I can get the f*ck off the planet with my immediate family, to settle in Alpha Centurai.
Or, rather, mass. To get to Mars you first have to get into Earth orbit. At a cost of roughly $10,000/pound. That, mind you, is just low Earth orbit. Where the shuttle orbits. To get to Mars you then have to get to escape velocity (which is higher than orbital velocity), 11100 m/s. Add more cost.
She was the captain of the 1989 MIT Volleyball team, and the first MIT grad to be inducted into the Verizon Academic All-American hall of fame.
She was a hottie back then too- read all about it at this [mit.edu] webpage.
Actually, you got the math wrong. Also, one of your premises was wrong: it moved 10 feet, not 3. (even though the back of the rover is ~3 feet from the lander, it had to drive the front wheels off the lander, then move far enough so the back rolls across the lander, off the ramp, and another 3 feet beyond)
There are 3600 seconds in an hour, so Spirit would travel (3600/78) * 10 = 461.538 feet, or a little under 1/11 mile per hour. (0.08741, to be more exact)
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Revisit Sojourner! (Score:5, Interesting)
I've been really hoping that one day they'll go back to the original Sojourner site and return that unit to Earth for analysis by NASA. They could gain valuable information as to what finally gave on that rover and use it to harden future rovers.
Sojourner was a great success as it lasted much longer than expected. Of course the cost of getting that unit back to Earth would be so high I'm guessing these are just nice dreams. C'est la vie.
Re:Revisit Sojourner! (Score:5, Insightful)
Re:Revisit Sojourner! (Score:5, Insightful)
Re:Revisit Sojourner! (Score:5, Interesting)
Wild-ass guess, but the wiper mechanism would probably get jammed by dust just about the time if could be useful in cleaning off the solar cells.
Seriously, even the scientists on the project wanted an RTG in the thing. They could have driven it around for *years* if they had. Instead, they got solar panels which (due to dust) have an expected lifetime of about 1/2 a year. Stupid environmentalism...
Re:Revisit Sojourner! (Score:3, Informative)
Radioisotope Thermal Generator
If you punch it into google, you'll find that it takes the heat from plutonium or strontium-90 and turns it into usable electricity. There are no moving parts and no fission or fusion reaction. It's just a lump of rock (actually metal) that gets very hot.
SRG stands for Stirling Radioisotope Generator
These are more efficient power sources that use the heat from radioisotopes to power a stirling engine (the precursor
Re:Revisit Sojourner! (Score:4, Interesting)
Re:Revisit Sojourner! (Score:3, Interesting)
Anyway, some simple low-risk ideas:
* A small air blower jet to blow the dust off. After all, there is an atmosphere (albeit a thin Martian one) to work with.
* Tilt the panels and give them a gentle shake to get most of the dust off.
* Use an electrostatic coating to keep the fine dust from sticking.
As far as the batteries, couldn't they b
Re:Revisit Sojourner! (Score:5, Informative)
It had a solar panel and a primary battery. It was only meant to run for a few days.
Bruce
Re:Revisit Sojourner! (Score:5, Interesting)
True, but dust and grit would eventually gum up most of the instruments and make wheels stick. The Viking landers didn't do much "moving" science after their first few months (after scooping soil, etc.) They mostly just tracked weather and looked around every now and then.
Making moving parts and instruments dust-resistant and/or cleanable would probably greatly add to the cost I would expect. In other words, power is only half the problem.
Further it costs something like 3 million USD a day to operate rovers (personell, communications, etc.) Thus, extended durations eat money in other ways.
And, it might be better science to have multiple short-distant rovers exploring a variety of marsographically[1] separated areas rather than one to two long-distance rovers. In other words, spend the money on quantity instead of duration.
And, "nuke" power cells are not politically popular due to possible launch crash risks.
[1] As opposed to GEOgraphically.
Re:Revisit Sojourner! (Score:3, Informative)
While I generally agree with the rest of what you say, please don't call RTGs "nukes". They're simply heavy metals that emit some radiation and really don't post a threat to anyone. Heck, you've probably got similar materials in your backyard [cameco.com]. But we're *never* going to convince people otherwise if we don't stop calling them "nukes".
Re:Revisit Sojourner! (Score:5, Insightful)
But safe enough to hold with gloves...
and there is a small chance that one could burst from launch errors...
The odds that one would burst are about as close to zero as they get. The RTG itself is sealed inside a "black box" type of shielding. The stuff is strong enough to survive reentry from orbit! An explosion of the rocket wouldn't even phase it (as past launch failures have shown).
Actually, that's why NASA launches over the ocean. If something does fail, it falls into an unpopulated area (i.e. miles of water).
I agree that the risk is tiny, but it does exist.
You have a greater chance of getting cancer from your cell phone battery.
Noboby sane claims they explode into mushroom clouds.
You'll love this guy [slashdot.org]. He still hasn't taken me up on my "nuclear challenge". I wonder why?
Re:Revisit Sojourner! (Score:3, Funny)
Re:Revisit Sojourner! (Score:3, Informative)
*cough* *choke* *gag*
I can't believe I've got another one of you people [slashdot.org]. We're not even talking about a nuclear pile/reactor! We're talking about stuff similar to what's in your BACKYARD [cameco.com]!
Did you know that plutonium gives off Alpha radiation?
Did you know that Alpha radiation is not in any way shape or form dangerou
my usual RTG post (Score:3, Informative)
RTG's are very, very, very safe. The poisonous gasses released by a rocket explosion are far worse than what an RTG can do. Here's why.
RTG's contain Plutonium 238, (an isotope which cannot be used in fissile weapons, its too unstable) that generate lots of heat which is how they work. Now a note about the safety of Pu238.
Plutonium is among the safest to handle radioactive elements. It only generates alpha particles
Re:Revisit Sojourner! (Score:4, Informative)
Re:Revisit Sojourner! (Score:3, Insightful)
I doubt that NASA has the funds or enough desire to go through all this to recover the craft.
Kinda sad though
Re:Revisit Sojourner! (Score:3, Insightful)
Re:Revisit Sojourner! (Score:3, Funny)
Re:Revisit Sojourner! (Score:2)
;)
Re:Revisit Sojourner! (Score:2, Interesting)
For $400 Million... (Score:5, Funny)
"Mike's New Car" (from Monsters Inc) (Score:2)
It's like unleashing a panther.
Short Mission Duration (given the cost) (Score:5, Interesting)
I've read that this mission is limited by the build up of dust on the rovers solar cells, reducing the power attained to the point where the rover can no longer function.
An obvious solution (to me, here in my comfy chair) would seem to be the ability of the rover to gently tilt and/or shake its panels to remove at least some of the dust.
Since the rover arrived with it's panels folded could it just fold and unfold them again to shake some of it off?
It seems such a pity for the mission to end for such a mundane reason since I presume it would otherwise continue until the batteries failed or physical wear/damage destroyed some key component.
Solutions for other missions spring to mind, perhaps:
- blowing the dust away with a small directed jet of compressed air.
- A small fan or brush on a simple arm.
- Speciali(s|z)ed tilt/shake schemes (as above).
- Raise the panels up on a windy day (without blowing over).
- Layers of protective film that can be peeled away.
dust removal -- static charge? (Score:3, Interesting)
I wonder if there might be some way to build up a charge to clean them off? Shaking or tilting probably wouldn't work -- look at the crap that gets stuck on your car over time and it doesn't come off at over 100km/h.
I've read that some sort of solar panel wipers or brushes wouldn't work as they'd scratch the surface, allowing less light to reach it.
The plastic film idea reminds me of the removable visor strips racecar drivers have on their helmets. Sounds like a good one. Patent? Boo, hiss ;-)
Re:dust removal -- static charge? (Score:3, Informative)
Re:Short Mission Duration (given the cost) (Score:5, Informative)
I'm not sure of the specifics, but the missions principal scientist was my professor in college and he specifically said that they tried some of your exact ideas for the next rover (which was actually a cancelled 2003 mission). They tried a windshield-wiper type deal, layers of plastic film that would roll off every few days (think like a doctor's office, how they tear off that butcher paper and roll a new cover over for each new patient).
He didn't delve too much into specifics, but he definately said that they simply didn't get any of these ideas to work. Actually, there was a brief period of time when they were actually close to getting RTGs to power the rovers (plutonium, like the ones used in the Viking landers that allowed them to operate for 5 years), but the Greens stopped that
Re:Short Mission Duration (given the cost) (Score:3, Informative)
So the solar cells will provide less power due to the lower sun angle and brightness, even without any dust accumulation.
Assuming no major mishaps, what will eventually kill the rover is lack of power to heat the electronics at night. Electrical components don't last very long unprotected from the wild temperature swings
More info (Score:4, Informative)
Here's a photo [spaceflightnow.com] of the landing platform it just rolled off of.
From the cited article: 'Data from the Spirit rover shows it completed this morning's drive off the lander at 3:41 a.m. EST. Confirmation was received on Earth just before 5 a.m. EST, verifying that Spirit had performed the 10-foot voyage on its own.
The move took approximately 78 seconds, ending with the back of the rover about 2.6 feet away from the lander egress ramp, officials report.
"It's as if we get to drive a nice sports car, but in the end we're just the valets who bring it around to the front and give the keys to the science team," says flight director Chris Lewicki.'
Who let the jugs out? (Score:4, Funny)
Oh for the love of... Really, we didn't need to hear this. I hope that didn't get caught on film because that's the sort of thing that resurfaces at retirement parties.
Re:Who let the jugs out? (Score:2, Funny)
Better than the song they played as it rolled off. (Score:2)
According to an NPR report this morning, they played the theme from Rawhide (Rollin' rollin' rollin'...) as they sent instructions for the rover to leave the platform.
I tell you what, those rocket scientists have one seriously inverted sense of humor sometimes.
Re:Who let the jugs out? (Score:2)
Way to go (Score:5, Funny)
Way to go and really enforce those nerd stereotypes. Come on guys.
NASA also has photos, straight from their fake set in Hollywood where they produce all the "space" footage.
That is such a big lie!
Those sets have been moved to India.
Re:Way to go (Score:2)
Sorry chaps (Score:5, Funny)
This is a picture of Mars, hope you like it!
Wishing you were here,
The US of A
Oh come on, laugh, it's not meant to be an insult!
Re:Sorry chaps (Score:2)
"
This is a picture of Mars, hope you like it!
Wishing we were here,
The US of A
"
Re:Sorry chaps (Score:5, Funny)
Dear USA,
Hey, we are here, and here, and over here, and oooh, here's another piece of Beagle over here!
The United Kingdom of Great Britain and Northern Ireland
Re:Sorry chaps (Score:2)
I send this to you in order to have your advice!
Hugs and kisses,
Gretta Britaine.
Attachments: Mar_Polar_Lander_Sucks_and_Dies.doc
(Two can play at that game!
Beagle to final communication mode (Score:5, Funny)
will shred it's own parachute and lay the pieces out across the martian surface to spell the world "HELP".
Calculations suggest that each letter will be approximately 4-6 pixels across, easily discernable from the Mars Express orbiter.
High winds may hamper this last ditch attempt for Beagle 2 to communicate.
(I'm allowed to laugh, some of my tax money is spread all over the red planet)
Yeh, but ... (Score:2)
I'm a little worried... (Score:5, Funny)
Re:I'm a little worried... (Score:2)
what leaders? We will just see some poor homeless martians toying with the machine until they accidentally destroy the cameras. Then a one who is smarter will try to sell it for food.
Not from Hollywood. (Score:3, Funny)
[ObRant]Sheesh! If you're not going to pay attention to the facts, then why bother posting???[/ObRant]
Re:Not from Hollywood. (Score:2, Funny)
Need a new one .... (Score:2, Funny)
Mind you area 5 is surrounded by lots of nice desert - rip out the sagebrush and only film at night (everyone knows it's always night on the moon,
Re:Not from Hollywood. (Score:2)
So true. Never let facts stand in the way of openning your yap. I never have.
Air Bag in Photo (Score:2)
Why was moving dangerous? (Score:3, Interesting)
However, I don't understand why they kept saying that moving the rover off the lander was "dangerous". I thought the rover was designed to be able to deploy even if the lander came to rest upside down. Instead it was right-side-up on level ground. The rover had to drive over the deflated balloon, but why was that more dangerous than just driving over the surface?
sPh
Re:Why was moving dangerous? (Score:5, Informative)
Because mission engineers had tested the same setup (airbag position, rover position) and found that the orignal exit ramp had a chance that the rover's solar panel would get caught on the airbag. They decided to opt for the safest route, and turned the rover around and out through the second exit ramp.
Spaceflightnow.com has all the details. [spaceflightnow.com]
-Cyc
Re:Why was moving dangerous? (Score:2)
but why was that more dangerous than just driving over the surface?
I don't recall them saying it was more dangerous. I think they just said that it was dangerous.
I, for one, would consider almost any maneuver by the rover to be dangerous. After all, this is the first time those components have experienced leaving the Earth's atmosphere, existing in Mars' atmosphere, and everything in between.
Many
Why Moving the Rover Was Dangerous (Score:5, Insightful)
* Suppose some part of the rover had been broken on landing, but had not surfaced yet because it had not moved. Think of a broken neck - it doesn't cause paralysis until you move and sever your nerves.
* Take advantage of a controlled situation. They wanted to take advantage of a controlled situation for as long as they could. From the lander they could take panoramic pictures from a sligh elevation. They could atmospheric measurements, etc. All this could be done without the adding the possible failure points introduced by moving the rover.
* The lander has more solar panels and perhapse some better communication hardware. Might as well take advantage of them while you're there.
I just pulled those off the top of my head. I'm sure there are better reasons and it's been discussed here before. Will you people stop bickering about them taking too long to move it?
How's this: Give me 3 equally good reasons why they should have hurried to get it off the lander.
Re:Why was moving dangerous? (Score:2, Informative)
Spirit actually had to roll off a 4-5" drop at the bottom of the ramp, possibly because of rocks, uneven ground, etc. That drop would've flipped Sojourner, for example, on its back. Being the size of a golf cart, Spirit has some advan
Re:Why was moving dangerous? (Score:2)
That's what I like to see: a practical use for Robot Wars technology
Does it also have a big spinning disk and a wedge design for upending other robo^H^H^H^H Martia... oh, never mind!
Re:Why was moving dangerous? (Score:2)
The airbags were designed to deflate in sequence so if the lander came to rest wrong way up after its bouncedown it could right itself before opening up to reveal the rover. If the lander got stuck upside down, like in a crevasse, then there would be no way of deploying.
The sequence of activities to ready the rover for movement off the lander were the most complex series of steps ever undertaken by a space probe. Dozens of small pyrotechnic devices had to be fired to release clamps, sever cables and so on.
dr4m4 0n m4r5... (Score:2, Funny)
His friend is a talking pie.
now we'll know... (Score:2, Funny)
the waiting is over ---but (Score:3, Interesting)
Well I am glad to see that the thing did not get stuck on a balloon.
The chance of spirit getting stuck made me think. (For the next ones we make) Why not get some very small solid rocket engines and put them facing in all directions on this thing. If the rover gets stuck, then as a last resort they could try igniting one or more of these small rockets engines to try and dislodge the rover. These rocket engines would probably be the smallest model rocket engines (or smaller) since I would hope you wouldn't need much of a bang to move in the Martian gravity. They are also pretty cheap.
granted you'd only get one shot, but if it's a last resort it's better to have one shot then none.
Re:the waiting is over ---but (Score:2, Funny)
Re:the waiting is over ---but (Score:3, Funny)
Great idea! Duct tape $5 bottle rockets all over the rover! That'll definitely decrease its chances of failure. Brilliant!
You wouldn't happen to work in the European Space Agency, would you?
Re:the waiting is over ---but (Score:2)
That only counts if you're going up, i.e. pulling against the gravity of the planet. The mass of everything involved is still the same, and that governs the amount of force you need to move against inertia.
So if you need to push the rover around, you'll need similar-sized forces (i.e. engines) that you'd need on Earth*.
(*) For the pedants: OK, the atmosphere is thinner, and the lack of gravity would reduce friction
Re:the waiting is over ---but (Score:4, Insightful)
A common reaction to the realization of a vulnerability is to add complexity to address the vulnerability. This is often a bankrupt strategy.
Wouldn't you feel silly if the "next ones" incorporated exactly this suggestion, and were unusable upon landing because "a small rocket engine, included to address the possibility of a rover getting stuck, ignited on re-entry and destroyed several critical components..."
On projects like this, every gram of hardware costs pounds of fuel, every contingincy plan requires man-weeks of meetings, and every non-essential task added to the process list amounts to a lost opportunity for a once-in-a-lifetime experiment. The last thing you want is find youself facing actual mission failure because of some contingency you put in place to address a possible mission failure.
Re:the waiting is over ---but (Score:2)
Mars is tiny (Score:3, Funny)
Re:Mars is tiny (Score:2)
Re:Mars is tiny (Score:2)
Mars Watch (Score:2)
Dance Monkey!! (Score:5, Funny)
A bunch of sweaty scientists dancing around the lab to "who let the dogs out"? Was Steve Ballmer there?
Mars must be really small... (Score:3, Funny)
rock formations (Score:3, Funny)
Sniff a rock! (Score:5, Insightful)
Oh man what a hack (Score:5, Funny)
Shotgun first drive! Of course I realize it's not like an RC car, but I can imagine right?
Re:Oh man what a hack (Score:3, Informative)
You can even download via Bittorrent...those JPL guys are so nerdy it's great.
I downloaded and skimmed the manual but haven't tried it myself yet, but from the manual it's apparent you can view your rover in 3rd-person 3D.
Interesting soil (Score:5, Informative)
Flash forward to today and we've got the "magic carpet", and dirt sticking to Spirit's wheels, sans digging - very interesting, and by the sounds of it also very unexpected. It will be great to find out what's making it stick, and just "how Mars works" in general.
Did I ever mention how glad I am humanity has another rover on an alien world?
Re:Interesting soil (Score:3, Informative)
Extremly fine dusts will act similar to this depending on the type of
Look at those tracks!! (Score:5, Funny)
I hope it doesn't get stuck, it'd suck to have to call a tow truck (or a martian redneck with a winch) to get it out:)
Official pics (Score:5, Informative)
Meanwhile on VENUS ... (Score:5, Interesting)
Anyway, as reported by the BBC [bbc.co.uk], American scientist Don Mitchell [mentallandscape.com] found the original Soviet Venera probe data from the surface of Venus and he applied modern image processing techniques to it to produce some stunning new pictures [mentallandscape.com].
He also has a really fantastic site about the Soviet Venera probes [mentallandscape.com].
Rich.
Re:Meanwhile on VENUS ... (Score:2)
All the more proof (Score:2, Insightful)
Honestly, what would we gain by sending humans?
Easy! Re:All the more proof (Score:2)
In the medium run: Footage of that first step onto the Martian surface for crazed conspiracy theorists to pour over, looking for proof it was filmed in the Gobi Desert.
In the long run: Footage of that first step onto the Martian surface for MTV to repurpose.
(This is a funny post, but I could write a serious one too, but I'm also sure someone else will. Whether the someone else w
Re:All the more proof (Score:4, Insightful)
Face it, the earth is fragile and life on it only temporary until we figure out how to live without it.
Not to mention that humans doing experiments on mars GREATLY reduces the latency. How long does a round trip signal take? I could go on and on about why we want humans on mars.
Dear Earthlings: (Score:3, Funny)
O.J.'s Revenge (Score:2)
Like this [imdb.com]?
Spirit Rolls on Mars (Score:2)
a rose is a rose (Score:2, Funny)
Sean O'Keefe (Score:2)
nick
The set isn't in Hollywood.. (Score:3, Funny)
Didn't you ever wonder what Area 51 was really for?
Spirit Rolls? (Score:3, Funny)
Backwards hazard camera? (Score:4, Funny)
Re:You'd think the fake would be obvious .... (Score:2)
Re:Nice Article Summary... (Score:5, Insightful)
it's jackass commentary like this that does nothing but perpeptuate bullshit to the masses and misinforms that average (read stupid) american. then the average (read stupid again) american's think these things are a waste of money.
Right, and how many "average Americans" do you know who (A) read Slashdot and (B) won't pick up the sarcasm in the original statement?
It's humor (though I'll agree, it's not really funny). Don't sweat it.
Re:Nice Article Summary... (Score:5, Funny)
Re:Nice Article Summary... (Score:2)
Re:Nice Article Summary... (Score:2)
Would not the sun have to circle us every 24 hours to make this myth work?
Re:flimsy looking (Score:2)
Re:flimsy looking (Score:5, Insightful)
If you could do all of that, and deliver a package with the neccesary weight, size, and other various launch/flight/deployment constraints.. then you would be (by far) the best robot designer on the planet. Ohh ya, and be able to do all of those things reliably on an alien world millions of miles away.
These are smart people (I've had the privilige of working with two of them), that are well aware of all of those possibilities. The realities of design have to come into play at some point, and that's how these things really come about.
Re:flimsy looking (Score:4, Funny)
G) In the event of Giant Spring failure, the last resort is the Plasma Cannon.
H) In the event the Plasma Cannon initiates full scale interplantary war, it activates the Omega 13 device, reverses time, and destroys itself before it deploys the Plasma Cannon.
I) In the event of the Time Reversal Self Destruction Manuevor still incurring the Martian overlord's wrath, it sends a signal to me, so that I can get the f*ck off the planet with my immediate family, to settle in Alpha Centurai.
J)
Weight (Score:2)
Re:Jennifer Trosper is a VOLLEYBALL PLAYER! (Score:3, Informative)
Re:Would it help if I got out and pushed? (Score:3, Interesting)
There are 3600 seconds in an hour, so Spirit would travel (3600/78) * 10 = 461.538 feet, or a little under 1/11 mile per hour. (0.08741, to be more exact)