Posted
by
CmdrTaco
from the congrats-from-the-news-nerds-to-the-nasa-nerds dept.
tvh2k writes "CNN reports that both the Mars Rovers Spirit and Opportunity are now both fully functional. Working on opposite sides of the red planet, they have begun analyzing rock and soil samples."
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I guess the idea of a redundant rover is to make sure that errors are not a total loss. But it's nice to have both, especially since Opportunity seems to have found evidence of water. This has been really exciting to follow.
NASA/JPL learned their lesson when the Mars Polar Lander disappeared. Most Mars probes up until then had actually consisted of two spacecraft (the Mariner series and Viking 1/2) simply for redundancy; if your launch failed or the spacecraft blew up (Mars Observer, anyone?) there was a complete second set of spacecraft hardware available.
With two rovers that redundancy is back, and at the same time you can target them into two different landing zones on Mars, doubling your data sampling if they both survive.
That's a funny quote and all but I don't know if it's entirely true in this case. A lot of the cost involved was put towards getting the technology together and paying the people involved. Once one was built, the other one just required the same set of parts and a team to assemble and test it. No R&D costs were repeated.
While it's not exactly assembly line type savings, there is a reduced cost for building a duplicate of something that already has been built.
That's a funny quote and all but I don't know if it's entirely true in this case. A lot of the cost involved was put towards getting the technology together and paying the people involved. Once one was built, the other one just required the same set of parts and a team to assemble and test it. No R&D costs were repeated.
While it's not exactly assembly line type savings, there is a reduced cost for building a duplicate of something that already has been built.
That's true, and FYI, they actually built three rovers, just in case there was an accident with one of them before launch.
That's true, and FYI, they actually built three rovers, just in case there was an accident with one of them before launch.
Yes, but they didn't duplicate all of the most expensive equipment. I know this because I saw a TV program about the project, and there they worried about running a possibly destructive test on a camera they were sending to Mars. If they broke it they wouldn't have time to build a new one.
principle of government procurement: why buy one when you can buy two at twice the price
I'd mod this -1, ignorant. Generally with advanced projects like this the cost is hardly 1=N, 2=2N. The first one might cost a ton, but the second one, being a simple duplication of parts and methods developed for the first, is far, far cheaper (sometimes as much as an order of magnitude).
But hey, who am I to stand in the way of a pointless swipe at The Government?
The launches are clustered so tightly (2 weeks) because the optimal launch window for mars occurs every two years. Otherwise, it might make sense to do a yearly launch so that design problems (like the flash memory error) can be thoroughly tested and fixed.
Having two rovers operating at the same time might cause a reliability problem... if spirit had kept randomly transmitting at odd times, it might have interefered with good data being sent from opportunity. Nasa thought of that, and that's probably why the two rovers are on opposite sides of the planet - hence, only one is visible to earth and/or the relay satellite at a time, so they can't interfere.
Uh, that doesn't make much sense- I really doubt the two rovers would be interfering with one another if they were in the same area, as they could simply use different frequencies or cooperate on when they were going to transmit data, or work as master/slave...
There's a huge number of ways they could be working in the same area. The reason they're not is because there would be no point to it.
Master/slave would have less than one quarter the reliability, and cooperation doesn't work if one is going haywire (as did Spirit).
Different frequencies is good, but if they are close together and picked up the the same transponder (a likely scenario), a difference in amplititude could mess up the auto gain control and you'd lose the quiet one. A difference in amplitude could be caused by a number of reasons - poor aim, weak transmitter batteries, haywire transmit power setting, or a special max-power emergency reach-home mode. If the transmitters are frequency-agile (by design or accident), then they could still accidently transmit on the same frequency.
Physical seperation is your best bet if you want signifcant bandwidth and want the most flexibility to recover from a variety of failure modes.
Something I've been curious about, and I'm sure there's a reason for it, is why the landers don't use signals to an orbiter, which then can use higher power to transmit back to earth? Is this just too complex or is there another reason this scenario won't work?
Did a little research on this specific mission (before I was just talking based on my experience with the much smaller satellites I worked on), and I learned some stuff:
The forwarders are much better (bigger antennas, more solar cells = better power budget, higher orbit means the earth is visible for a bigger portion of the day), but they're another link in the system and prone to failure. (I'm guessing that they don't provide as many emergency debug options, either)
This page [nasa.gov] includes a description of the low-bandwidth control channel that communicates directly to the DSN.
I couldn't find mention of how much use the high gain-to-DSN path gets vs. via-relay-satellites path - does anyone have this info?
Actually, I'm an EE who has has some on-orbit hardware and software. Your examples are kindof primitive because these instruments have been implemented in a variety of very different ways, but I'll run with them.
Cell phones use a range of frequencies. Sometimes these frequencies are reused, and this is either CDMA or TDMA. TDMA is essentially cooperation; CDMA will suffer the same power differential problems that near-frequency transmissions will.
Cordless phones are similar - either multiple FM frequencie
I think it would have been excellent science to have Beagle operational at the same time. Imagine, three rovers investigating Mars at the same time, given "similar" environmental conditions (either a lack of or similar-intensity dust storm conditions).
We should be glad the problematic file stores on Spirit and Opportunity were easy to correct.
Remember they had three redudant rovers (Spirit, Opportunity and Beagle 2). In the big scheme of things Beagle 2 took one for the team, stiff upper lip and all that. However, I can reveal that despite Beagle 2's problems contact was recently reestablished as follows:
Jodrell Bank: I command you, as King of the Britons, to move! Beagle 2: I move for no man. Jodrell Bank: Report damage! Beagle 2: 'Tis but a scratch. Jodrell Bank: A scratch? Your wheels are off! Beagle 2: No, they're not Jodrell Bank: Well, what's that pile of molten slag? Beagle 2: I've had worse. Jodrell Bank: Eh. You are indeed brave, Sir Beagle, but you are no longer operational Beagle 2: Oh, had enough, eh? Jodrell Bank: Look, you stupid bastard. You impacted the surface of Mars at high speed, your camera's broken and you've got no wheels Beagle 2: Yes I have. Jodrell Bank: Look! Beagle 2: Just a flesh wound.
I would have hated to have been the tech support guy on that call:
Me: "So the machine is spontaneously rebooting every hour or so?" JPL: "Yeah, it looks like it's having a problem reloading the flash filesystem" Me: "Can we do an "ls" on that directory to see what's in it?" JPL: "Hold on..."
... 45 minutes later...
JPL: "ls came back with an error... no such file or directory" Me: "Hm, did you type the command correctly" JPL: "Yeah we typed 'lf' and that's the error we got." Me: "L... F.... no no no..."
by Anonymous Coward writes:
on Tuesday February 03, 2004 @12:26PM (#8170683)
They were GOING to, but the touchy-feely tree-huggers scared enough people into believing that if the launch went sour, there would be a nuclear explosion killing millions of people..
Yet another example of the left thinking only of their agenda...
But to supply a generator large enough to obviate the need for solar cells most likely would blow the weight budget (soft landing, remember?). Just my guess.
BZZT. 2.5 pounds of Plutonium per 75 watts of electricity. That's probably not that much heavier than the solar panels. The best part is that you'd need less battery with an RTG (just enough for large power draws) so you can save more weight there than your RTG costs you.
Ah, but the Vikings only had a very small power requirement. The only things electricity were needed for were the intruments. The rovers need to move under their own power. Futhermore solar panels are cheaper and simpler and lighter.
At lastly, since they only have enough money to pay people to run them for a couple months, why design a rover to last years?
You don't need the staff on hand because it's all in the 'hands' of the rover.
I think you underestimate how many people are involved with the operation of the rover. Even to recieve the transmissions, you need a very powerful reciever, because the transmissions from the rover are on the order of a Watt. This means time at a radio antenna must be spent. Furthermore, you must carefully craft the intructions to be sent,you must monitor the status of the rover (without human intervention Spirit would have
What about having the reactor in the base station, and the rovers moving back to it to recharge? or better yet, give it a full service station, imcluding solar panel cleanings, battery recharge. Also why dont the rover have some kind of wipers to stop the buildup?
Also why dont the rover have some kind of wipers to stop the buildup?
I wondered the exact same thing, and asked all the scientists I spoke to at JPL (for TechTV) that very question. They said that the added weight, and potential for joints and servos to fail outweighed the possible benefit of wiping off the solar panels. One of them told me that they were effectively routing out milligrams of weight from various areas of the rovers to get the total down.
I didn't ask about the base station (because I didn't think of it -- that would have been a good question) but I imagine they'd say the same thing about weight vs. benefits.
That is a herculean programming effort -- it's not like you can go up there and push "reset" on the robots when something doesn't work. NASA continually pushes the limits of computers to make these projects work within budget, and I look forward to the public release of some new tools and data from the rocks! I hope for their sake, we find a fossil or something like that -- no more budget problems for NASA...or would there be?
It's more like 150 million miles, but the analogy still applies! I believe the specifics for the lander can be had at spaceflightnow.com [spaceflightnow.com].
I've found this [spaceflightnow.com] site very informative, with frequent rover status updates, links to images, NASA press releases and details of rover activities.
So, is the power leakage on the Opportunity rover also fixed or are they just going to put up with a shorter lifespan of the machine?
My understanding is that it is still not resolved. Appearently the rovers can still work in the day with a dead (non-rechargable) battery, but the cold from lack of heaters eventually damages electronics. Thus, one way or another it will probably shorten the mission (assuming something else does not bust or dust-up first).
I am so happy they both work and are well. Hopefully this will lay the groundwork for future missions and maybe a base on mars.
This is also good news as a precision check. If one did not work off the bat, we would not have anything to compare the results to.
From the artice:
Halfway around Mars from its twin, Opportunity already has discovered an iron-rich mineral called gray hematite. Preliminary measurements suggest the mineral is of a variety that forms in liquid water, providing the first hint that
From the CNN article, apparantly Spirit can dust off a rock. It doesn't say how though, but I would guess either compressed air brought from earth (unlikely), a little air compressor, or a brush of some sort.
Now, apparantly the lifetime of the rovers is limited by the rate at which dust build up on the solar panels. How hard could it have been to reticulate the arm so that it can bend around and dust the panels off themselves? Even if it were to cost $1mil, it'd still be worth it as it would extend the lifetime of the rovers indefinately.
(Personally, I'd still like to see a better solution- have the rovers shake like dogs do when they get wet)
I have heard that it's really important that space probes -- especially ones that have large staff to run them like the MER-A and -B -- need to have some kind of life-limiting feature. Otherwise, you could never realistically budget them. Also, you have to consider the strain on the shared resources -- the Deep Space Network in particular. There are quite a few systems that depend on the Deep Space Network, which is monopolized to a large extent by Spirit and Opportunity today.
The other major life-limiting feature on Spirit and Opportunity are the batteries. They can't be cycled indefinitely. Opportunity, in particular, with its arm heater always on, is going to overtax its battery system relatively quickly. It will probably get to its 90-day design life, but not much further.
Spirit will likely go quite a bit longer. It's warmer there than expected, which means that they don't have to run the internal heater at night as much as they thought. They are seriously talking about an extended mission for Spirit -- maybe up to 180 days. This would give it time to drive quite a long ways, maybe even up to the nearby mountains about 1.5 km away.
My understanding from earlier articles is that they aren't "brushing off" the rocks, but rather "grinding" off a circular area of the rock so that they can get to the unmodified interior of the rock. So, even if the arm can reach up to "scratch its own back", so to speak, you probably wouldn't want to use the grinder to dust off the solar panels:-)
In yesterday's briefing, Jennifer Trosper mentioned usinig the RAT brush to clean accumulated dust off of Adirondack before taking surface measurements with the Mossbauer and APXS.
The tool that does the grinding (Rock Abrasion Tool aka the RAT) also has a brush mechanism so they can brush dust fromt he surface of the rock before taking measuremnet of the rock. They'd like to take readings from the rock surface as that might give information about how the rock has weathered which might in turn give clues to past environments. Dust particles could obscure the readings from the actual rock surface hence the brush.
After they take the surface reading they can use the RAT to grind off t
Yes, I thought the same thing. But my solution would be some sort of pump or vacuum because if you packed compressed air you'd have a limited supply. At least with some mechanism for shooting air you'd be able to use it time and time again.
However, this answer seems so obvious and trivial so I'm pretty sure it's already been addressed.
The rovers can either use their Rock Abrasion Tool (RAT) to grind a short way into rocks or (leave it to nasa to think up very simple solutions) dig a small hole using one of its wheels if the top layer is too deep to penetrate with the RAT. They are considering doing this at the Opportunity site.
I heard rumblings a while back (may have been on/.) about alternative space exploration to our current methods. Basically launching hundreds of smaller robots at a task rather than a single highly developed bot. They mentioned lots of benefits, like 80% failure rate would still generate something. Additionally they would be near eachother and possibly work together and even repair one-anothother.
Has there been anymore talk about things like this?
There are other advantages as well. Suppose you were to build 8k explorers in batches of 100. Suppose 80% of the first batch failed. Taking the information from the failures, the second batch could be better as the bugs would be found and reduced. Say a 50% failure rate for the second batch. Lather, rinse, repeat.
Instead of 'one offs' a standardized product would be developed, built on the learning of the previous batch. Once the failure rate was below a certain percentage, say 1%, some (maybe 10%) could b
I have seen many many pictures of the erosion and channels and lake beds on mars over the years. Many many pictures... and they all looked very convincing, because it was so similar to the effects that water has on earth.
Then at the start of the Spirit and Opportunity landings, I started to think about it more. Something bothered me about the way the erosion appeared. It seemed there was no source for the water. I started thinking what might have caused features similar to that caused by running water. I think it is caused my lava flows. I could be completely wrong, and probably am, but maybe what I interpret as not being features caused by water, are really features that were caused by a very early and short-lived time of running water.
The water source for the Martian channels is weird. It is certainly not rain: the channels don't spread out enough and there are closed drainage systems. Planetary scientists (I am one) think that the channels might have been formed by sapping: the water comes out of the ground in a spring.
The dish might be fine, but you'd need to set the correct frequency. You'd also need one hell of a super-low-noise amp in order to pick the signal out of the background noise. That's the difference between "deep-space" and Earth orbit signals.
Question for the real radio guys out there:
Is the size of the dish on a radio telescope analogous to the size of the mirror on a more typical visible-light telescope?
Is the size of the dish on a radio telescope analogous to the size of the mirror on a more typical visible-light telescope?
Yes. The larger the dish, the higher the gain and narrower the beamwidth. At microwave freqs (the rovers are around 8 GHz) the 'figure' of the dish becomes very important. An error of 1/10 lambda (wavelength) can mess up the pattern of a dish.
by Anonymous Coward writes:
on Tuesday February 03, 2004 @12:36PM (#8170852)
Of course.
You're talking about the nation that invented the telephone, the airplane, radio, television, the atomic bomb, the hydrogen bomb, landed a man on the moon, has sent probes to every planet in the solar system, the modern computer, the internet, and WMD in iraq.
Do you think two pissant little rovers on mars are a problem? We did this already almost 30 years ago.
People. Hello. This is the US of A. Everybody else talks a good game, but we kick ass.
The telephone was invented in Boston, and the patent specification was written in Brantford.
I live one hour away from Brantford and would love to support that claim to fame, but according to the Alexander Graham Bell Museum in Baddeck, NS (a Canadian National "Park" which I have also visited), the telephone was not invented in Canada.
Pretty easy for the armchair engineers to opine, but I wonder if all non-trivial projects simply paraphrase Clausewitz [clausewitz.com] to read "No non-trivial project survives contact with reality".
Props to these guys for having a design that allows remote repair in the event of the unforseeable.
Not to be a smartass, but I wonder what the systems are like on these vehicles. I saw several stories on CNN stating that the first Rover had to have some excess files removed so that it had more available memory. Plus a couple of reboots. That harkens me back to the days of MS-DOS running memmaker and looking at UMB's, HMA, etc.
I recall reading somewhere that much of the NASA technology behind the Apollo missions could be replaced by a modern day handheld scientific calcluator. What's the story nowadays?
They're generally rad-hardened and tested not to fail it, which means they don't launch with cutting edge technology. On top of that, the time between building one of these and it landing is years...
No, you're not being cynical, but there is a valid reason - the testing and burn-in phase, which can take months if not years. If memory serves me correctly, there was a recent probe that ran on 4 Intel 486 processors. Why didn't they use the then available Pentium 2? Testing - the 486's they had were proven to work in the extreme environments and it would have caused unneccessary delays to test with a new processor / motherboards.
Personally, I wouldn't be that surprised in the Rovers were running Red Hat
They run on Vxworks [windriver.com], a real-time operating system (RTOS) which has been used by NASA for several years now. You have to remember that these aren't run of the mill systems, but ones that need military grade radiation hardened components, and it's amazing what can be done even with a simple embedded system (I wrote a minimal TCP/IP stack and ethernet driver for an 8-bit processor once, the 8052, and while complex). It's mostly technology that has proven to be reliable time and time again, but not all codepaths can be explored even in a simple system. The problem with spirit was apparently in the flash filesystem implementation (sounded like they ran out of inodes, but I haven't seen a detailed analysis).
After Spririt and Opportunity complete their missions....assuming they have enough juice in their batteries left over, I think Nasa should have the two robots meet each other and duke it out. If they are each at opposite ends of Mars, how fast can the rovers move?
For those wondering what hematite looks like, you can drift over to your
local New Age shoppe to take a look at the hematite
jewelry [metastones.com] as well as find out its alleged properties. [earthbow.com]
Hematite is a good stone for those born during the Moon of Renewal - (22
Dec- 19 Jan.) Its grounding and soothing energies can help you relax and
unwind both physically and mentally. Hematite's renewing qualities also
make this stone an excellent match for those born during this time of the
year, but everyone can benefit from this stone.
Hematite is a good choice for those born under the zodiac sign of Virgo.
Opportunity's landing and "birth" on Mars are a bit late for Jan 19th, but
close enough. Renewing properties might help the flash memory and
batteries, and if there's one thing a Mars rover can always use, it's
grounding!
(Be warned: Valentine's Day is coming up, and you can never go wrong with
cutesy jewelery, but remember that some hematite is magnetic.)
Do they have a similar setup of the Rover's internals?
I mean, do they have a duplicate that they could fill up the flash memory and try and fix it when there's no latency? Then follow the steps on the rovers?
Not to bring up the color calibration controversey again, but Nasa has published a detailed two-part feature on calibrating the pancam. The first part can be viewed here [nasa.gov] and the second can be found here. [nasa.gov]
This feature was presented to the mission managers during one of the 'lunchtime lectures' they present in the MOC. I caught a glimpse of this presentation the other night while watching the NASA TV stream. [nasa.gov] The presenter mentioned/. during his presentation and talked a little bit about the color debate started here a few weeks ago.
What I still haven't seen is a full, technical explanation of what went wrong in the first place, and (more importantly) why it wasn't caught in ground testing. One would imagine that flash-contention issues would be relatively easy to bench test.
As with Pathfinder, NASA seems to have run into testable software issues only after the hardware is on another planet. I'd like to see more morning-after analysis on this both so NASA can improve its process for future missions, and so that we can all learn something about software testing for our own projects.
Does anyone know of place (web page, mailing list, whatever) where this is being discussed on a deep technical level?
I don't have a link handy but the reason it wasn't caught in testing is because the longest test they ran was 9 days. The errors started to happen (IIRC) 18 days into the mission.
Most news sites are too damn slow for news on the rovers. Hell, Spirit was fully up and running over two days ago.
Visit the official MER web site from JPL [nasa.gov] for at least better day-to-day detail.
Another geeky thing to enjoy is Maestro [nasa.gov], software that allows anyone to download real data from both landers and observe in exhaustive detail what the JPL guys see (they use a much more complex version of the package). It's Java.
Why the hell not? Just remember, those fourth graders will one day be adults. Adults that are going to have influence, one way or another. Perhaps the child in question, inspired by this, will go on to be an astronaut?
While the great scientists of old (and young) have their place, we have to think of the future, too.
Am I the only one disapointed by the names of these probes? When I think about space projects, I think they should be named after great scientists...not names generated by 4th graders as part of a contest.
Can you think of a name that *hasn't* already been used at some point in the last 40 years? Yeah, names of great scientists would be nice, but any name that could be remotely related to the mission has already been used. It seems kinda pointless to have named the two rovers "Salk" and "Pasteur" simply because they were important scientists...
So you're telling me Hubble was a household name before that big lens in the sky got there? Hell, call them Tycho and Brahe. Leonardo and Michaelangelo. SOMETHING. Bill and Ted comes to mind as the perfect example.
people who don't seem to have read anything by George Orwell?
"They" have almost certainly read and understood George Orwell only too well. "They're" simply counting on relatively few of the unwashed masses having read George Orwell, or to have comprehended it if they have.
Given current political events in the United States, and the persistent popularity of its president among said unwashed masses despite his appalling history [bushin30seconds.org] in office thus far, "they" seem to be quite correct in this assumption.
What difference does it make if you and I snicker at the Orwellian names our space missions are routinely given, or the pithy propoganda that accompanies every "3...2...1...ignition" sequence (the "of [whatever] in another [whatever] for [whatever]" that always gets tagged on to the countdown these days), so long as 9 out of 10 vegitative Americans take it seriously, and more than half of America is vegatative?
To summarize [bushin30seconds.org]: "TERRORIST TERRORIST TERRORIST, 9/11, 9/11, God Bless America"
here is a website [para-normal.com] with more of that stuff... personally, i see it as a 'seeing what you want to see' syndrome, just like the 'face of mars'.
For some reason (Score:5, Funny)
Still, Re:For some reason (Score:5, Funny)
'Spirit is willing but the flash is weak' over and over again...
Very good news (Score:5, Informative)
Re:Very good news (Score:5, Insightful)
Re:Very good news (Score:5, Funny)
This also vindicates a longstanding principle of government procurement: why buy one when you can buy two at twice the price!
Re:Very good news (Score:2)
Re:Very good news (Score:3, Informative)
While it's not exactly assembly line type savings, there is a reduced cost for building a duplicate of something that already has been built.
Re:Very good news (Score:4, Informative)
While it's not exactly assembly line type savings, there is a reduced cost for building a duplicate of something that already has been built.
That's true, and FYI, they actually built three rovers, just in case there was an accident with one of them before launch.
Re:Very good news (Score:3, Interesting)
Three Rovers (Score:3, Funny)
Uh oh.
Not a comlete rover (Score:3, Informative)
Yes, but they didn't duplicate all of the most expensive equipment. I know this because I saw a TV program about the project, and there they worried about running a possibly destructive test on a camera they were sending to Mars. If they broke it they wouldn't have time to build a new one.
Re:Very good news (Score:5, Insightful)
I'd mod this -1, ignorant.
Generally with advanced projects like this the cost is hardly 1=N, 2=2N.
The first one might cost a ton, but the second one, being a simple duplication of parts and methods developed for the first, is far, far cheaper (sometimes as much as an order of magnitude).
But hey, who am I to stand in the way of a pointless swipe at The Government?
launch window & redundancy (Score:5, Interesting)
Having two rovers operating at the same time might cause a reliability problem... if spirit had kept randomly transmitting at odd times, it might have interefered with good data being sent from opportunity. Nasa thought of that, and that's probably why the two rovers are on opposite sides of the planet - hence, only one is visible to earth and/or the relay satellite at a time, so they can't interfere.
Re:launch window & redundancy (Score:4, Insightful)
Re:launch window & redundancy (Score:5, Insightful)
Different frequencies is good, but if they are close together and picked up the the same transponder (a likely scenario), a difference in amplititude could mess up the auto gain control and you'd lose the quiet one. A difference in amplitude could be caused by a number of reasons - poor aim, weak transmitter batteries, haywire transmit power setting, or a special max-power emergency reach-home mode. If the transmitters are frequency-agile (by design or accident), then they could still accidently transmit on the same frequency.
Physical seperation is your best bet if you want signifcant bandwidth and want the most flexibility to recover from a variety of failure modes.
Re:launch window & redundancy (Score:3, Interesting)
Re:launch window & redundancy (Score:4, Informative)
How rovers communicate with earth [nasa.gov]
- the Deep Space Network (DSN) communicates directly with the rovers, but is busy because it also tracks 28 other missions.
- the rovers can talk to one of two mars-orbiting satellites [nasa.gov] that will forward the messages.
The forwarders are much better (bigger antennas, more solar cells = better power budget, higher orbit means the earth is visible for a bigger portion of the day), but they're another link in the system and prone to failure. (I'm guessing that they don't provide as many emergency debug options, either)
This page [nasa.gov] includes a description of the low-bandwidth control channel that communicates directly to the DSN.
I couldn't find mention of how much use the high gain-to-DSN path gets vs. via-relay-satellites path - does anyone have this info?
Re:launch window & redundancy (Score:3, Informative)
Cell phones use a range of frequencies. Sometimes these frequencies are reused, and this is either CDMA or TDMA. TDMA is essentially cooperation; CDMA will suffer the same power differential problems that near-frequency transmissions will.
Cordless phones are similar - either multiple FM frequencie
what about gulls? (Score:4, Funny)
Mine? Mine! Mine.....mine!mine!mine! mine!mine!mine!mine!MINE!mine!
Re:what about gulls? (Score:3, Funny)
Re:Very good news (Score:3, Insightful)
We should be glad the problematic file stores on Spirit and Opportunity were easy to correct.
Re:Very good news (Score:5, Funny)
Jodrell Bank: I command you, as King of the Britons, to move!
Beagle 2: I move for no man.
Jodrell Bank: Report damage!
Beagle 2: 'Tis but a scratch.
Jodrell Bank: A scratch? Your wheels are off!
Beagle 2: No, they're not
Jodrell Bank: Well, what's that pile of molten slag?
Beagle 2: I've had worse.
Jodrell Bank: Eh. You are indeed brave, Sir Beagle, but you are no longer operational
Beagle 2: Oh, had enough, eh?
Jodrell Bank: Look, you stupid bastard. You impacted the surface of Mars at high speed, your camera's broken and you've got no wheels
Beagle 2: Yes I have.
Jodrell Bank: Look!
Beagle 2: Just a flesh wound.
John.
SSH Session (Score:5, Funny)
Re:SSH Session (Score:5, Funny)
Me: "So the machine is spontaneously rebooting every hour or so?"
JPL: "Yeah, it looks like it's having a problem reloading the flash filesystem"
Me: "Can we do an "ls" on that directory to see what's in it?"
JPL: "Hold on..."
JPL: "ls came back with an error... no such file or directory"
Me: "Hm, did you type the command correctly"
JPL: "Yeah we typed 'lf' and that's the error we got."
Me: "L... F.... no no no..."
Dont tell me you don't feel my pain, too.
Great - (Score:5, Insightful)
Nasa, next time take a lessen from the past and harness the power of the atom - the Viking probes lasted for years.
Re:Great - (Score:5, Funny)
Yet another example of the left thinking only of their agenda...
Re:Great - (Score:4, Informative)
BZZT. 2.5 pounds of Plutonium per 75 watts of electricity. That's probably not that much heavier than the solar panels. The best part is that you'd need less battery with an RTG (just enough for large power draws) so you can save more weight there than your RTG costs you.
Sorry, tree huggers are the problem.
Re:Great - (Score:5, Insightful)
At lastly, since they only have enough money to pay people to run them for a couple months, why design a rover to last years?
Re:Great - (Score:3, Interesting)
I think you underestimate how many people are involved with the operation of the rover. Even to recieve the transmissions, you need a very powerful reciever, because the transmissions from the rover are on the order of a Watt. This means time at a radio antenna must be spent. Furthermore, you must carefully craft the intructions to be sent,you must monitor the status of the rover (without human intervention Spirit would have
Re:Great - (Score:2, Interesting)
care and feeding of rovers (Score:4, Informative)
I wondered the exact same thing, and asked all the scientists I spoke to at JPL (for TechTV) that very question. They said that the added weight, and potential for joints and servos to fail outweighed the possible benefit of wiping off the solar panels. One of them told me that they were effectively routing out milligrams of weight from various areas of the rovers to get the total down.
I didn't ask about the base station (because I didn't think of it -- that would have been a good question) but I imagine they'd say the same thing about weight vs. benefits.
Congrats to NASA - robust programming (Score:5, Insightful)
Re:Congrats to NASA - robust programming (Score:2, Funny)
I'll get my coat... taxiiii
Re:Congrats to NASA - robust programming (Score:5, Funny)
Oh..wait...
Re:Congrats to NASA - robust programming (Score:2)
Finally! (Score:5, Funny)
So, how long 'til they meet? (Score:5, Funny)
"Battlebots: Martian Showdown"
Re:So, how long 'til they meet? (Score:5, Funny)
"Spirit just detected iron in Opportunity's left solar panel! Advantage Spirit!! Oh wait, here comes Beagle... DEATH FROM ABOVE!!!" *wham*
Yes, but... (Score:3, Funny)
Rover status updates (Score:5, Informative)
Power leak (Score:5, Interesting)
Re:Power leak (Score:5, Informative)
My understanding is that it is still not resolved. Appearently the rovers can still work in the day with a dead (non-rechargable) battery, but the cold from lack of heaters eventually damages electronics. Thus, one way or another it will probably shorten the mission (assuming something else does not bust or dust-up first).
This is great news!!!! (Score:2)
This is also good news as a precision check. If one did not work off the bat, we would not have anything to compare the results to.
From the artice:
Halfway around Mars from its twin, Opportunity already has discovered an iron-rich mineral called gray hematite. Preliminary measurements suggest the mineral is of a variety that forms in liquid water, providing the first hint that
if it can dust one thing, why not another (Score:5, Interesting)
Now, apparantly the lifetime of the rovers is limited by the rate at which dust build up on the solar panels. How hard could it have been to reticulate the arm so that it can bend around and dust the panels off themselves? Even if it were to cost $1mil, it'd still be worth it as it would extend the lifetime of the rovers indefinately.
(Personally, I'd still like to see a better solution- have the rovers shake like dogs do when they get wet)
Re:if it can dust one thing, why not another (Score:5, Informative)
The other major life-limiting feature on Spirit and Opportunity are the batteries. They can't be cycled indefinitely. Opportunity, in particular, with its arm heater always on, is going to overtax its battery system relatively quickly. It will probably get to its 90-day design life, but not much further.
Spirit will likely go quite a bit longer. It's warmer there than expected, which means that they don't have to run the internal heater at night as much as they thought. They are seriously talking about an extended mission for Spirit -- maybe up to 180 days. This would give it time to drive quite a long ways, maybe even up to the nearby mountains about 1.5 km away.
thad
Re:if it can dust one thing, why not another (Score:3, Funny)
What, no $99 battery replacement plan?
Re:if it can dust one thing, why not another (Score:5, Informative)
My understanding from earlier articles is that they aren't "brushing off" the rocks, but rather "grinding" off a circular area of the rock so that they can get to the unmodified interior of the rock. So, even if the arm can reach up to "scratch its own back", so to speak, you probably wouldn't want to use the grinder to dust off the solar panels :-)
Re:if it can dust one thing, why not another (Score:2)
In yesterday's briefing, Jennifer Trosper mentioned usinig the RAT brush to clean accumulated dust off of Adirondack before taking surface measurements with the Mossbauer and APXS.
RAT (Score:3, Informative)
After they take the surface reading they can use the RAT to grind off t
Re:if it can dust one thing, why not another (Score:2)
However, this answer seems so obvious and trivial so I'm pretty sure it's already been addressed.
Re:if it can dust one thing, why not another (Score:2, Informative)
stateside however (Score:3, Funny)
Window for Opportunity? (Score:2, Interesting)
More, nearer. (Score:5, Interesting)
Has there been anymore talk about things like this?
Re:More, nearer. (Score:3, Insightful)
Instead of 'one offs' a standardized product would be developed, built on the learning of the previous batch. Once the failure rate was below a certain percentage, say 1%, some (maybe 10%) could b
It's all fun and games... (Score:4, Funny)
Poor little guys.
Another story about the Mars rovers? (Score:2, Insightful)
Knowledgeable discussion? On Slashdot? That'll be the day.
Erosion caused by water (Score:4, Interesting)
Then at the start of the Spirit and Opportunity landings, I started to think about it more. Something bothered me about the way the erosion appeared. It seemed there was no source for the water. I started thinking what might have caused features similar to that caused by running water. I think it is caused my lava flows. I could be completely wrong, and probably am, but maybe what I interpret as not being features caused by water, are really features that were caused by a very early and short-lived time of running water.
Re:Erosion caused by water (Score:5, Informative)
water source (Score:5, Interesting)
Without Spirit and Oppourtinuty functioning (Score:2, Funny)
please don't punnish me for this.
.
Check for root kits (Score:2, Funny)
Re: (Score:2, Insightful)
Re:satellite dishes (Score:2)
The dish might be fine, but you'd need to set the correct frequency. You'd also need one hell of a super-low-noise amp in order to pick the signal out of the background noise. That's the difference between "deep-space" and Earth orbit signals.
Question for the real radio guys out there:
Is the size of the dish on a radio telescope analogous to the size of the mirror on a more typical visible-light telescope?
Re:satellite dishes (Score:2)
Is the size of the dish on a radio telescope analogous to the size of the mirror on a more typical visible-light telescope?
Yes. The larger the dish, the higher the gain and narrower the beamwidth. At microwave freqs (the rovers are around 8 GHz) the 'figure' of the dish becomes very important. An error of 1/10 lambda (wavelength) can mess up the pattern of a dish.
American Ingenuity (Score:5, Funny)
You're talking about the nation that invented the telephone, the airplane, radio, television, the atomic bomb, the hydrogen bomb, landed a man on the moon, has sent probes to every planet in the solar system, the modern computer, the internet, and WMD in iraq.
Do you think two pissant little rovers on mars are a problem? We did this already almost 30 years ago.
People. Hello. This is the US of A. Everybody else talks a good game, but we kick ass.
Re:American Ingenuity (Score:2)
but you do bring up an interesting question.
how come we can find signs of water on a planet several million miles away but we can't find signs of WMD on a country several thousand miles away?
You have it backwards (Score:3, Informative)
The telephone was invented in Boston, and the patent specification was written in Brantford.
I live one hour away from Brantford and would love to support that claim to fame, but according to the Alexander Graham Bell Museum in Baddeck, NS (a Canadian National "Park" which I have also visited), the telephone was not invented in Canada.
Government of Canada's version [pc.gc.ca]
Joke (Score:2, Funny)
Where else can you fake a Mars landing?
Props to NASA (Score:5, Insightful)
Props to these guys for having a design that allows remote repair in the event of the unforseeable.
There's a reason... (Score:2)
sPh
What's the underlying technology? (Score:2)
I recall reading somewhere that much of the NASA technology behind the Apollo missions could be replaced by a modern day handheld scientific calcluator. What's the story nowadays?
Re:What's the underlying technology? (Score:3, Insightful)
Tim
Re:What's the underlying technology? (Score:3, Informative)
Personally, I wouldn't be that surprised in the Rovers were running Red Hat
Re:What's the underlying technology? (Score:5, Informative)
Robot Wars (Score:2, Funny)
NASA discovers Martian New-Age gift shop! (Score:3, Funny)
(Be warned: Valentine's Day is coming up, and you can never go wrong with cutesy jewelery, but remember that some hematite is magnetic.)
Software Information (Score:2)
I've seen a couple places with some information, but not anything with any good amount of detail.
I'd rather like to encourage my students to read about it.
Back on Earth (Score:2)
I mean, do they have a duplicate that they could fill up the flash memory and try and fix it when there's no latency? Then follow the steps on the rovers?
Cool Details on Color Calibration (Score:5, Informative)
This feature was presented to the mission managers during one of the 'lunchtime lectures' they present in the MOC. I caught a glimpse of this presentation the other night while watching the NASA TV stream. [nasa.gov] The presenter mentioned /. during his presentation and talked a little bit about the color debate started here a few weeks ago.
Interesting rock formation (Score:4, Funny)
I get the impression someone got there first
nick
Bug report (Score:5, Interesting)
As with Pathfinder, NASA seems to have run into testable software issues only after the hardware is on another planet. I'd like to see more morning-after analysis on this both so NASA can improve its process for future missions, and so that we can all learn something about software testing for our own projects.
Does anyone know of place (web page, mailing list, whatever) where this is being discussed on a deep technical level?
Re:Bug report (Score:3, Informative)
SP
In a nutshell (Score:3, Informative)
The Site to Visit & Software to Play With (Score:5, Informative)
Visit the official MER web site from JPL [nasa.gov] for at least better day-to-day detail.
Another geeky thing to enjoy is Maestro [nasa.gov], software that allows anyone to download real data from both landers and observe in exhaustive detail what the JPL guys see (they use a much more complex version of the package). It's Java.
Re:The Site to Visit & Software to Play With (Score:3, Informative)
Your wish is their command [nasa.gov].
More MER Info (AXCH) (Score:3, Informative)
(AXCH) 2004 Mars Exploration Rovers - News, Status, Technical Info, History [axonchisel.net].
Re:Name gripe (Score:5, Insightful)
While the great scientists of old (and young) have their place, we have to think of the future, too.
Re:Name gripe (Score:2, Funny)
This is Houston. We're ready to roll Stinky Ga-Ga onto the Martian surface.
Anonymous Kev
Proudly posting as AC since 1997
Re:Name gripe (Score:4, Funny)
Re:Name gripe (Score:4, Insightful)
Can you think of a name that *hasn't* already been used at some point in the last 40 years? Yeah, names of great scientists would be nice, but any name that could be remotely related to the mission has already been used. It seems kinda pointless to have named the two rovers "Salk" and "Pasteur" simply because they were important scientists...
Re:Name gripe (Score:3, Interesting)
Re:Name gripe (Score:3, Insightful)
Well, we are not there in actuality, but in Spirit
And NASA had the Opportunity to build and send two.
Re:Name gripe (Score:3, Funny)
Beavis and Butthead?
Christina and Britney?
Frodo and Samwise?
Re:Name gripe (Score:2, Interesting)
Who the hell comes up with these names?
Re:Name gripe (Score:5, Funny)
It vindicates "them" (Score:4, Insightful)
"They" have almost certainly read and understood George Orwell only too well. "They're" simply counting on relatively few of the unwashed masses having read George Orwell, or to have comprehended it if they have.
Given current political events in the United States, and the persistent popularity of its president among said unwashed masses despite his appalling history [bushin30seconds.org] in office thus far, "they" seem to be quite correct in this assumption.
What difference does it make if you and I snicker at the Orwellian names our space missions are routinely given, or the pithy propoganda that accompanies every "3...2...1...ignition" sequence (the "of [whatever] in another [whatever] for [whatever]" that always gets tagged on to the countdown these days), so long as 9 out of 10 vegitative Americans take it seriously, and more than half of America is vegatative?
To summarize [bushin30seconds.org]: "TERRORIST TERRORIST TERRORIST, 9/11, 9/11, God Bless America"
Re:Sorta OT, but still relevant (Score:2, Insightful)
Actually... (Score:2)
The number was "13" and the inscription beneath it read "Fo shizzle, ma robizzle! -S.D.".
It seems hip-hop killed the early Martians.
Re:Sorta OT, but still relevant (Score:2)
It's because this picture was taken in a studio. Nobody never ever went to the moon and no robots never even landed on Mars.
Everything you can see is pure manipulation from NASA and the government.
[/sarcasm]