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Mars Rover Opportunity Surpasses 30km Driving

Soulskill posted more than 2 years ago | from the still-hasn't-found-a-white-castle dept.

Mars 86

Phoghat sends this quote from Universe Today: "With her most recent drive of 482 feet on June 1, 2011 (Sol 2614), NASA's Opportunity Mars Rover has zoomed past the unimaginable 30 kilometer mark in total odometry since safely landing on Mars nearly seven and one half years ago on Jan 24, 2004. That's 50 times beyond the roughly quarter-mile of roving distance initially foreseen. And Opportunity is still going strong, in good health and has abundant solar power as she continues driving on her ambitious overland trek across the martian plains of Meridiani Planum. She is heading to the giant Endeavour crater, some 22 km in diameter."

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86 comments

kilometer conversion for the math impared (4, Funny)

Average_Joe_Sixpack (534373) | more than 2 years ago | (#36337010)

That would be 0.000001668 of a light minute

Re:kilometer conversion for the math impared (1)

wjh31 (1372867) | more than 2 years ago | (#36337064)

i am perplexed as to why you chose to convert from SI units to light minuites. If you are going to convert from SI units it would make more sense to me to convert to plank units, in which case 1Km=16.16E39lp.

Re:kilometer conversion for the math impared (1)

jd (1658) | more than 2 years ago | (#36337614)

The sun is 8 light minutes away, so it becomes easy to figure out how many astronomical units it has moved.

Re:kilometer conversion for the math impared (0)

Anonymous Coward | more than 2 years ago | (#36337698)

Augh! Planck! Max Karl Ernst Ludwig Planck!

Re:kilometer conversion for the math impared (0)

Anonymous Coward | more than 2 years ago | (#36337556)

Or 17628 Smoots

Please, use Mars units (1)

mangu (126918) | more than 2 years ago | (#36337654)

One kilometer in Mars is close to one arc-minute along the surface.

Incidentally, that was the definition reason for the nautical mile on earth, it's one arc-minute along the sea surface.

Re:kilometer conversion for the math impared (0)

Anonymous Coward | more than 2 years ago | (#36338464)

the correct SI unit for measuring temporal distances is the second. If you want to show off your belief in special relativity, then you should use seconds.

The distance is a tenth of a millilightsecond.

units (0)

hey (83763) | more than 2 years ago | (#36337020)

Arg, feet and kilometers in the same paragraph equals a mess.

Re:units (1)

multisync (218450) | more than 2 years ago | (#36337054)

Agreed. Opportunity drove 146.9 meters to reach the 30 Kilometer mark.

Re:units (0)

Anonymous Coward | more than 2 years ago | (#36337384)

Technically, it drove 30 Kilometers to reach to 30 Kilometer mark.

Re:units (1)

jd (1658) | more than 2 years ago | (#36337632)

No, because it has velocity relative to Mars. It must have therefore travelled a nearly-infinitesimal amount more than 30 kilometers to reach the 30 kilometer mark.

Re:units (0)

Anonymous Coward | more than 2 years ago | (#36337068)

"482 feet"
"30 kilometer mark"
"50 times beyond the roughly quarter-mile"

Hilarious. Also, 30km is about 75 times a quarter-mile, or 50 times about a third-mile. I think the diameter of the Endeavor crater should have been written in furlongs (almost 110!).

I hate to say it but... (0)

Anonymous Coward | more than 2 years ago | (#36337028)

when we get to Mars that piece of shit will likely have grown arms and legs to show us around and how fucking boring that planet is...

How about consistent measurement units in summary? (1, Offtopic)

blahbooboo (839709) | more than 2 years ago | (#36337034)

Great job slashdot editors at making the summary (sarcasm). Why do you use both kilometers and miles in the summary for making the comparison? Spend 4 seconds to at least be consistent so the reader can quickly understand the scale in constant units. Here let me help:

30km is the distrance traveled, and they expected the rover to go only 0.4km
or
48.28 miles is the distance traveled, and they expected the rover to go only 0.25 miles

Re:How about consistent measurement units in summa (1)

rolfwind (528248) | more than 2 years ago | (#36337058)

Since when is 30km = 48 miles?

30km = ~18.6 miles

Re:How about consistent measurement units in summa (1)

jd (1658) | more than 2 years ago | (#36337640)

Smaller planet. On Mars, the milestones are closer together.

Re:How about consistent measurement units in summa (0)

Anonymous Coward | more than 2 years ago | (#36337080)

Who taught you math? And English?

Re:How about consistent measurement units in summa (1)

blahbooboo (839709) | more than 2 years ago | (#36337198)

Me learn english meself.

Re:How about consistent measurement units in summa (1)

rubycodez (864176) | more than 2 years ago | (#36337338)

you're lucky, you should see what the victims of the U.S. educational system write

Re:How about consistent measurement units in summa (0)

Anonymous Coward | more than 2 years ago | (#36337436)

u r lol! lol!

Robot gender (1)

Anonymous Coward | more than 2 years ago | (#36337036)

her ambitious overland trek... She is heading to the giant Endeavour crater...

I had no idea the Opportunity Mars Rover was female.

Re:Robot gender (1)

jd (1658) | more than 2 years ago | (#36337682)

It is conventional for all vehicles and containers to be considered female. Not sure if the convention comes from the Latium family of languages, but that's certainly what I was taught. It seems a little odd, since most older languages have a neuter gender. English has become so degenerate over the years that it lost the capability to represent anything other than male or female. You'd therefore expect English to be the language that used such forms, but no. French and German both have neuter but don't use it for things that lack gender.

(Which implies that the origin of gender terms had nothing to do with how they're used today.)

Re:Robot gender (0)

Anonymous Coward | more than 2 years ago | (#36337920)

(I'm french) French does not have neuter.

Which means that in french, all objects have a gender...

Re:Robot gender (1)

MichaelSmith (789609) | more than 2 years ago | (#36338776)

The guy in the next cube from me keeps going Oh merde fucking excel but I can't figure out what gender excel belongs too..

Re:Robot gender (1)

Plunky (929104) | more than 2 years ago | (#36340706)

English has become so degenerate over the years that it lost the capability to represent anything other than male or female.

Whats funny is that I have a cup on my desk, and it is neither male nor female..

It is conventional for all vehicles and containers to be considered female.

AFAIK in german, ships are generally considered to be male.. (German speakers feel free to contradict, but I have a boat built by a german speaker and it has a male name)

Please Don't Mix Systems of Measurement (0)

Da Cheez (1069822) | more than 2 years ago | (#36337040)

""With her most recent drive of 482 feet on June 1, 2011 (Sol 2614), NASA's Opportunity Mars Rover has zoomed past the unimaginable 30 kilometer mark in total odometry since safely landing on Mars nearly seven and one half years ago on Jan 24, 2004. That's 50 times beyond the roughly quarter-mile of roving distance initially foreseen"

Dear Universe Today source article,
For the future, can we NOT mix our systems of measurement, please? Seriously, I don't know if I should be thinking in feet, kilometers, miles, or cubits right now. Please please please just choose metric or, if you must, US units. But whichever you choose, stick with one or the other when discussing one topic. Don't switch back and forth. It makes it impossible to get a good mental picture of what you're talking about in terms of scale.
Sincerely,
Self-righteous Complainer (but you left me no choice)

Re:Please Don't Mix Systems of Measurement (0)

Anonymous Coward | more than 2 years ago | (#36337130)

You should feel comfortable operating in any unit system. As a technically minded person (as you must be to be posting on Slashdot), you know that the system of units has absolutely no impact on the actually quantity being measured. The use of feet and km in this article make perfect sense. Actually I am so used to using both that I didn't even notice the different units

I don't know what all the hate is for the Imperial units is about. It is based on what feels comfortable for human beings to understand. Sure it might have started as "the length of an arm bone is a foot", but it has been held very to very rigorous standards since the mid 1800's. On the other hand, the SI system feels contrived and forces the human mind to adapt to a system of measurement which sometimes seems counter-intuitive. If you don't believe me go ask a Russian rocket engineer about the kgf. That discussion should tell you that the SI system is not perfect.

The english system is not going to disappear anytime soon. In an increasingly complex world you will have to learn to handle both. In fact, I hope the english system never dies.

So in short, stop complaining about the system of units and man up. You are whining about something that you cannot change and nobody likes to listen to a whiner.

Regards

Re:Please Don't Mix Systems of Measurement (2)

ShadowEFX (152354) | more than 2 years ago | (#36337294)

I see our resident Lockheed Martin Aerospace [wikipedia.org] representative has chimed in.

Re:Please Don't Mix Systems of Measurement (0)

Anonymous Coward | more than 2 years ago | (#36337816)

I haven't feed a troll lately and I'm not sure exactly what you eat, but here goes:

Wow! You caught me! I must work for LM since I am talking about units. Your deductive reasoning is reminiscent of Sherlock Holmes. But, can you tell me what working for LM has to do with anything? The faster, better, cheaper mantra must be your underlaying point I guess. Please try to sound intelligent when you respond.

Oh, and I do not work for LM.

Re:Please Don't Mix Systems of Measurement (1)

ShadowEFX (152354) | more than 2 years ago | (#36338298)

Nah, no hate intended...did you read either the WP article, or google the name of the lander? Here's another link [cnn.com] for you.

Your line:

You should feel comfortable operating in any unit system. As a technically minded person (as you must be to be posting on Slashdot), you know that the system of units has absolutely no impact on the actually quantity being measured. The use of feet and km in this article make perfect sense. Actually I am so used to using both that I didn't even notice the different units

Seemed like part of a conversation that might have taken place at LMA during this time. Fortunately, it did result in NASA placing even more strict controls on source code, both internal and contract.

I largely agree with your comment - folk should be able to at least understand how metric and Imperial units scale to each other. However, consistency does have its place.

Re:Please Don't Mix Systems of Measurement (1)

MichaelSmith (789609) | more than 2 years ago | (#36338794)

I work in the industry but not for Lockheed. In their defence measurement units in aerospace are hopelessly messed up. Vertical distances are measured in feet except in Russia where they are in metres. Some horizontal distances are measured in nautical miles and others in kilometres. Vertical speeds are measured in metres per second in gliders and feet per second elsewhere. I think they should pick a date (say Jan 1 2020) and just change everything to SI units. There will definitely be disasters as a result but they won't have the ongoing confusion which exists presently. And the companies which supply the avionics and ATC systems will be delighted with the money they will earn.

Re:Please Don't Mix Systems of Measurement (1)

ShadowEFX (152354) | more than 2 years ago | (#36339030)

Yeah, I didn't realize what a cluster things were in until that incident. I remember one of the reports that came out after the investigation suggested NASA switch to metric for all dealings with the public. It also said that units used were different from center to center, even program to program. I always wondered what became of that suggestion...based on what you said, sounds like not much.

Re:Please Don't Mix Systems of Measurement (0)

Anonymous Coward | more than 2 years ago | (#36337508)

but it has been held very to very rigorous standards since the mid 1800's.

Make that standards.
Every conuntry that today uses metrics still have their old set of imperial units documented. Since the summary doesn't specify if it is British feet and miles one could get pretty different results depending on what standard one uses.
A Wesel-foot is 23.51 cm while a Rhine foot is 31.387 cm.
A Rhineland mile is 4119 m while a Westfalia mile is 11100 m.
Those are only some of the German variations of the imperial units. If you where to compare the imperial units in all countries you might get a larger spread.

So when you wonder what all the hate about Imperial units is about you should know that it is nothing compared to the hate when they were commonly in use. One of the reasons we got rid of them was to avoid all the hate that occured in international trade when one ordered a certain amount of silk and received just because the imperial units were different between all countries.
It is still today a problem since there are still mechanical drawings around that uses imperial units where it's not specified what set of imperial units that are used. If one just assumes British iches on them one could end up with details that are way off.

Re:Please Don't Mix Systems of Measurement (0)

Anonymous Coward | more than 2 years ago | (#36337884)

Yes! You are very correct and I didn't state that in my earlier post. It was more a frustrated response to a complainer who can't understand units and how to use them.

First I agree completely with you. The imperial units have been refined to a high set of standards based on location around the globe. That was until the introduction of the SI system (which you pointed out correctly as a way to eliminate the confusion of international trade & communications). The modern world pretty much uses the SI system and the American version of the imperial units. It is true though that you will still find some older documents which use a local standard, but those are becoming quite rare now. For the most part you can safely assume that when someone says "feet", they are talking about the what we use in the US.

My original rant was against a dumb shit who is complaining about mixing units and not being able to handle it. Most industries work in both and fully expect everyone to be "fluent" in both. Hell, some of my latest calculations had units of mg/ft^2 for a surface coating. I'm afraid that would have made my little complainer friends head explode, but in actuality it makes the math easier and the result cleaner. Which that is the point of units anyway:)

Thank you for responding. It's been a while since I had a good discussion about units.

Re:Please Don't Mix Systems of Measurement (1)

Jesus_666 (702802) | more than 2 years ago | (#36337854)

The imperial systems would be less confusing if they were more consistent and adhered to how we work with numbers. Going from one unit to the next-bigger unit can mean a multiplication by three, six, eight, twelve, five-thousand two hundred and eighty and possibly other numbers as well. Even if the multipliers were consistent, multiplying something by twelve is rather unintuitive for someone used to a base-ten number system. The SI units have the advantage that moving from a bigger to a smaller unit or vice versa just means you determine how far the prefixes are away form each other and move the decimal point accordingly. As prefixes are shared between various units it's also easier to keep everything in your head.

I'd like the imperial units better if they looked like this:
1 inch = 0.0254 m
1 foot = 10 inches = 0.254 m
1 yard = 10 feet = 2.54 m
1 rod = 10 yards = 25.4 m
1 furlong = 10 rods = 254 m
1 mile = 10 furlongs = 2540 m

You'd still need to learn all those names and they wouldn't carry over to weights but at least conversions would be nice and easy.


By the way, the imperial systems are only really used in the UK and the USA. Given that the USA are unlikely to retain their current role as sole superpower, compatibility with the American measures and weights might soon be of concern only to North American countries.

Re:Please Don't Mix Systems of Measurement (1)

endymion.nz (1093595) | more than 2 years ago | (#36338056)

From the wiki article, 'The kilogram-force has never been a part of the International System of Units (SI), which was introduced in 1960. The SI unit of force is the newton.'

Re:Please Don't Mix Systems of Measurement (1)

turbidostato (878842) | more than 2 years ago | (#36338408)

"As a technically minded person (as you must be to be posting on Slashdot), you know that the system of units has absolutely no impact"

Well, it indeed has an impact... at great speed, against Mars surface no less. Ask Mars Climate Orbiter for further references.

Re:Please Don't Mix Systems of Measurement (1)

Nyeerrmm (940927) | more than 2 years ago | (#36343782)

While the difference in units was the most immediate culprit, it could have been a great number of other things and the real culprits were:

1. Failure by Lockheed to follow defined software interface specifications. The same thing could have happened if they used meters rather than km or a dozen other things.

2. High turnover on the Lockheed spacecraft team meant that no one who was there to initially define the software specs was still around, nor had they directly trained the new team members.

3. The JPL navigation team was understaffed and did not have enough oversight to properly sort out anomalous data that could have prevented the problem.

So yes, while the units thing was the superficial cause, its really just another example of human errors that will inevitably affect any human endeavor, particularly when they need to be very precise. Snidely focusing on the units thing is sidestepping the real issues of quality control and quality staffing. Fortunately we learn from our mistakes -- I know on the JPL Nav side we have a strong push for staffing plans being laid out with significant continuity for the lifetime of a project from PDR through the primary mission, as well as a renewed emphasis on keeping an external review panel for all nav procedures.

And Opportunity is still going strong... (2)

countertrolling (1585477) | more than 2 years ago | (#36337118)

Gee, I wish Slashdot could say the same for its servers

Error 503 Service Unavailable

Re:And Opportunity is still going strong... (2)

Megahard (1053072) | more than 2 years ago | (#36337212)

Apparently it was busy varnishing its cache. Then it had to take time out from its stressful life for guru meditation.

Re:And Opportunity is still going strong... (0)

Anonymous Coward | more than 2 years ago | (#36339782)

Varnishing its cache? Best pun I've heard all weekend. A tip of the hat to you, sir!

Re:And Opportunity is still going strong... (2)

zill (1690130) | more than 2 years ago | (#36337268)

That's because NASA employees are much more competent.

Try imagining slashdot editors launching space shuttles.

Non-units "holy war" thread here (4, Interesting)

vlueboy (1799360) | more than 2 years ago | (#36337140)

Ugh, 30 minutes and everyone's still caught up in the unit conversion issues.

OK, let's stop and ponder other things, like why these rocket scientists were 50 times off their mark on durability estimates. The are not the same people in charge of our cheap unshielded, non-harsh-weather resistant, poorly dust-proofed, China-made electronics where variable parts WILL fail every few years and stop your booting. Aerospace scientists design beyond "our" problems, and make complex computers with probably zero dust-exposed PSU heatsinks to live in dust-bunny/lightning storm environments 5+ times harsher than the Earth, wind-speed and static-electricity-storm-wise (courtesy of a Science channel doc).

The scientists have been revising data from all the mars rover landings since '97, and from the very first rover had a chance to up-correct their estimates when even *that* rover outlasted the projections. So... why are they erring on the side of caution? Politics, maybe washing their hands in the distrust of contractors' abilities to build good enugh to meet their 10-year-program adjustments spec? Something doesn't add up, and it makes you wonder:

* just how much better is "rocket science," really?
* just how much worse are all the others who more-readily miss estimates, causing daily problems on our Blue Marble?
* just how prepared is NASA to run tests beyond the driving reach of the landing site while they obviously didn't carefully plan to be running 'em?
* just how many extra tax dollars will need to be allocated to budget for this whole not-so-well planned "lucky break?" ;)

BEGIN!

Re:Non-units "holy war" thread here (2, Interesting)

Anonymous Coward | more than 2 years ago | (#36337216)

It's not that they are wrong on their predictions of how long a device should last. Look at it this way: When you send something out into space (like a rover to mars) you won't have the possibility of fixing it if it breaks. When the rovers where designed and constructed NASA said they wanted them to last six months so they had to have a probability of failing at six months that was extremely tiny (1% or whatever the number came out of my ass). Also the way that warrenties are designed (and I'm assuming they did math like this before) is that the probability of failure is assigned for different times. The designers didn't say the rovers would break at six months. They merely made (almost) absolutely certain that they would last at least six months.

Re:Non-units "holy war" thread here (0)

NNKK (218503) | more than 2 years ago | (#36337256)

It's not that they are wrong on their predictions of how long a device should last. Look at it this way: When you send something out into space (like a rover to mars) you won't have the possibility of fixing it if it breaks. When the rovers where designed and constructed NASA said they wanted them to last six months so they had to have a probability of failing at six months that was extremely tiny (1% or whatever the number came out of my ass). Also the way that warrenties are designed (and I'm assuming they did math like this before) is that the probability of failure is assigned for different times. The designers didn't say the rovers would break at six months. They merely made (almost) absolutely certain that they would last at least six months.

Except they never said six months. They said three months, insisted the solar panels would be too covered by dust to get enough power after that, and refused to consider any sort of cleaning system. Even when NASA gets something right, they get it completely wrong.

Re:Non-units "holy war" thread here (1)

Anonymous Coward | more than 2 years ago | (#36337546)

They said three months, insisted the solar panels would be too covered by dust to get enough power after that, and refused to consider any sort of cleaning system.

Except they *did* consider cleaning systems - they just decided they weren't worth the cost/benefit tradeoff.

When you send anything up in a rocket, weight is money. Adding any sort of cleaning device to the rovers would have increased the weight. Aside from the extra cost involved just in launching it (tens of thousands of dollars per pound for low earth orbit, even more for the delta-v to get to mars), you're probably working up against the design limit of the rocket in the first place. Anything you add to the rover means that you'll have to remove something else, or the rover just won't make it to mars in the first place.

I'm sure you could design an ingenious solar panel-clearing mechanism that only weighs a few ounces (just several 100 grams). All well and good, but those extra ounces means that you now can't add that ingeniously designed scientific instrument that only weighs a few ounces. The mars rover people looked at what they could put on the rover, an decided the extra scientific instrumentation for a shorter period of time was worth more than less instrumentation for a longer period of time. -- And you know what? They were right. They would have been happy with three months of extra scientific instrumentation, and here they've gotten several years of extra scientific instrumentation. And really, they wouldn't have been substantially better off with the panel clearing mechanism. The rovers really aren't suffering from having occasionally dirty panels. Even the dead rover really wasn't killed by a dirty panel, it was killed by a bum wheel. (While the proximate cause of death was low power, the reason it had low power was that it couldn't orient itself to get the best light because got stuck in the soil, partly because it had broken wheels. - You don't hear anyone berating NASA for not doing a better wheel design, though.)

Re:Non-units "holy war" thread here (1)

NNKK (218503) | more than 2 years ago | (#36337652)

You either completely missed the point, or didn't pay much attention to the ridiculous statements that came out of NASA when the rovers were being prepped (and thus missed the point anyway, oh well).

It was quite clear at the time that NASA was creating a very expensive self-fulfilling prophecy (panels will last three months without cleaning system, so we'll make the mission three months long, oh hey, the panels will last for the duration of the mission, so we don't need a cleaning system! yay! oh, and we're going to spend over 2x the cost of Pioneer 10 while chanting "smaller cheaper better"), and it is now equally clear that they couldn't even get that right.

I applaud the hardware engineering skills that went into the construction of what's there. I curse and ridicule the absurd thought processes that led to such an insane disconnect between the stated goals and the final results. As I said in the first place, even when NASA gets it right, it's wrong.

Re:Non-units "holy war" thread here (0)

Anonymous Coward | more than 2 years ago | (#36344088)

I think that *you* missed the point.

Say you're planning a mars mission, and one of the environmental engineers runs into the room and says "Guys! I just looked at the potential dust buildup, and I calculated that we're not going to be able to get the lifetime out of this thing that we want." Now do you:

A) Cancel the mission entirely, and try to get the leftover funds assigned to a tab at Benihana's
B) Reengineer the mission to include a cleaning system, which would by necessity mean removing scientific instruments
C) Accept the shortened lifespan, with the thought that three months of more instrumentation is worth more than a longer period with fewer instruments
D) Get congress to pass a law prohibiting mars from depositing dust on the solar panels

As A & D aren't really workable, it's a choice between B & C. NASA chose C. You seem to be favoring B. In retrospect, B would have been a *stupid* decision. The rovers survived without a cleaning system. With B, the rovers would be up there with fewer scientific instruments. There would have been no appreciable increase in rover longevity, and you would have missed out on the data the extra scientific instruments are giving you.

Even if the rovers *had* died at three months from dust buildup, NASA looked at the options and decided that they would have preferred three months of more instrumentation than six-to-twelve-plus months of less instrumentation, or even canceling the mission entirely. It's not "we don't need a cleaning system" but "we prefer a shorter mission without a cleaning system to a longer mission with fewer instruments". You might disagree with their priorities, but framing that as "refused to consider" is a gross mischaracterization.

Re:Non-units "holy war" thread here (1)

NNKK (218503) | more than 2 years ago | (#36344320)

You seem to be favoring B.

You are so wrong it's utterly pathetic. My point isn't that they should have added a cleaning system, my point is that they never should have been in the position of choosing between a 90-day mission lifetime at a cost of $820,000,000, or reengineering the rovers. If they didn't look at a possible dust problem in advance, they were negligent (we've known about Mars dust storms for over a century). If they did, and pressed ahead anyway, they were stupid. Either way, somewhere along the line they got the 90-day number, and it was STILL WRONG.

It's just another symptom of NASA's criminally negligent management. What I favor is the dismantling of NASA and the exile of everyone to have ever worked in management there from the entire aerospace industry (or, really, any job above flipping burgers, though I'm sure they'd screw that up, too). A few of them I want prosecuted for manslaughter, if not murder. It is a broken organization and so long as it exists, it is going to keep wasting ridiculous amounts of money while getting people killed.

Re:Non-units "holy war" thread here (0)

Anonymous Coward | more than 2 years ago | (#36338730)

Except they *did* consider cleaning systems - they just decided they weren't worth the cost/benefit tradeoff.

When you send anything up in a rocket, weight is money. Adding any sort of cleaning device to the rovers would have increased the weight. Aside from the extra cost involved just in launching it (tens of thousands of dollars per pound for low earth orbit, even more for the delta-v to get to mars), you're probably working up against the design limit of the rocket in the first place.

Actually, it's not so much the rocket. Mars entry and landing is incredibly difficult -- there's enough atmosphere to lose control of your actively-stabilized (retrorocket) lander in a wind gust, but not enough to slow down a passively-stable (parachute or airfoil) vehicle. The most successful scheme so far has been the aeroshell/parachute/retrorocket/airbag system used on Pathfinder/Sojourner, and reused for the MERs. The aeroshell covers the heat from entry, a supersonic 'chute controls most of the decent, dropping lateral speed to 10s of m/s, the retrorockets (attached to the upper aeroshell & chute, not the lander) fire long enough to reverse Vz at about 10m altitude, and the airbagged lander drops right at the bottom, with Vz=0 and minimum altitude, then bounces and rolls till the remaining lateral speed is exhausted.

The airbag system works great -- eliminates the need for zeroing Vx at all (the parachute and retrorockets keep going right above the lander), reduces the control requirements on the retros (allowing reliable solid-fuel motors), and reducing the impact of exact terrain details, but it doesn't scale real well, and the MER landers were very much at the limits of what we could reliably do with it.

And of course, what the "oh noes, it lasted 10x as long" crowd keep missing, is that it doesn't have a ridiculous power surplus with clean cells -- we overbuilt by maybe 20%, which might have doubled the mission to 6 months. Everything past that is due to unforeseen atmospheric dust clearing (dust devils and ordinary gusts), as opposed to the expected continual buildup. Yes, folks, strange but true, sometimes when you're exploring a strange world, you... *gasp* discover something you didn't already know, and that can invalidate your design parameters.

Re:Non-units "holy war" thread here (4, Insightful)

ColdWetDog (752185) | more than 2 years ago | (#36337588)

Except they never said six months. They said three months, insisted the solar panels would be too covered by dust to get enough power after that, and refused to consider any sort of cleaning system. Even when NASA gets something right, they get it completely wrong.

I see that you've been to Mars and understand the physics of dust in an alien atmosphere .... Oh, right. Anyhow, that isn't the issue at all. It's funding. Every NASA project is money constrained, so managers and boosters have all manner of strategems to make the most out of the system. Funding ground operations for 90 days is easier than funding ground observations for several years. Having a scientific package that meets it's goals in 90 days (and then goes ever onward) is much better than coming up with a 5 year plan and have some critical widget fail in three.

I really don't understand why everyone here is making such an issue of this. It's rocket science - it's an experiment. Sometimes experiments work, sometime they don't. Yes the lay press is all gaga about it but that's because the lay press has all of the intellect and introspective capabilities of a paramecium. It's working. It's making incredible scientific progress on the cheap. We should really be harping this aspect of the mission, not the warranty.

Slightly off topic. The Atlantic has a slide show on 11 things that Americans bizarrely get wrong about America [theatlantic.com]. It doesn't mention NASA but does mention that a significant number of Americans think that PBS funding and foreign aid constitute a significant amount of the US budget (actual values are less than 1% in both cases). There is this meme that the American government does nothing good and spends too much doing it. While there is some truth to that, a more important lesson is that the US government does lots of good things for not very much money. And this is one of those times.

Re:Non-units "holy war" thread here (1)

NNKK (218503) | more than 2 years ago | (#36337740)

Every NASA project is money constrained, so managers and boosters have all manner of strategems to make the most out of the system. Funding ground operations for 90 days is easier than funding ground observations for several years. Having a scientific package that meets it's goals in 90 days (and then goes ever onward) is much better than coming up with a 5 year plan and have some critical widget fail in three.

Funding my ass, they spent $820 million on the hardware, launch/transit, and 90-day operations (this during their era of chanting "smaller better cheaper"), and less than $125 million on continued operations since. On a budget that was already almost a billion dollars, you're going to tell me their primary motivation for pulling 90 days out of their ass was to save a few million on ground operations? No. Just no.

Re:Non-units "holy war" thread here (0)

Anonymous Coward | more than 2 years ago | (#36340024)

Uh, yes, that's how budgeting works. You do make the most insane local optimizations. (BTW, it's Faster, not smaller, thank you very much)..

The other thing is that there is a HUGE political need to define a baseline mission for which you can declare "mission success" that occurs relatively quickly.

Re:Non-units "holy war" thread here (1)

tlhIngan (30335) | more than 2 years ago | (#36350718)

Funding my ass, they spent $820 million on the hardware, launch/transit, and 90-day operations (this during their era of chanting "smaller better cheaper"), and less than $125 million on continued operations since. On a budget that was already almost a billion dollars, you're going to tell me their primary motivation for pulling 90 days out of their ass was to save a few million on ground operations? No. Just no.

A shuttle launch, just one, is over a billion dollars. Designing hardware to last longer than 90 days in under a billion dollars is much harder. Let's say you wanted it to work for a year. Now you have to design it to last a year.

Firstly, the battery had to last a year. The batteries in the rovers did just that - they lasted over 90 days (with recharging from the sun), then failed. The rovers have been operating strictly off solar power since. The solar panels were greatly oversized as they had to accomodate the charging of batteries plus normal rover operations plus whatever dust settles on the panels to reduce output.

Now instead of 90 day batteries, you had to design 1-year batteries, which may also include things like heating systems (more weight).

Also, now you have to ensure the panels are sized to either have a year's worth of dust on them plus an unfortunate orientation (when on the rocks the rovers would orient the panels so they'd catch the sunlight, especially in winter). Plus if they weren't oversized enough you'd need the cleaning mechanism (more weight) that had no consumables.

Etc. etc. etc.

And what happens if it broke after 9 months? That's billions wasted, and an experience failed because it didn't complete it.

No, the rovers lasted as long as they did simply because they were simple enough, worked well enough, and some very careful planning of their operations to ensure they would power up "tomorrow". Heck, there have been months where rover contact was lost and regained.

FYI - another rover is being sent that's much bigger. So big that they can't use the old airbag system anymore (Soujouner was around a shoebox, Spirit and Opportunity are more of a large shipping container. The one planned for late 2011 launch is SUV-sized with more instruments and an RTG to keep electronics warm so it'll work longer based on all the science we know now.

Re:Non-units "holy war" thread here (0)

Anonymous Coward | more than 2 years ago | (#36338988)

That poll seems a lot like they are polling random internet commenters or something... because there is no way in hell 20% of Americans that are medically sane believe that the sun orbits around the earth. Think about that for a minute. I would argue that anybody who believes that study is more gullible (and probably more stupid) than the average and the researchers who did it are completely incompetent. Also news, the average /.er thinks he's smarter than average. I would argue that nothing could be further from the truth given some of the moronic comments on this site, but hey let's keep feeding the lovely merry-go-round of intellectual masturbation.

Re:Non-units "holy war" thread here (1)

drinkypoo (153816) | more than 2 years ago | (#36341770)

Slightly off topic. The Atlantic has a slide show on 11 things that Americans bizarrely get wrong about America.

And speaking of bizarrely wrong, why does Cracked put its top n lists into a simple list article format which you can read, while the Atlantic puts lists into a slideshow format so you can click click click like a fucking idiot? Is this a sign of the capabilities of their relative audiences? Welcome to the idiocracy!

Re:Non-units "holy war" thread here (1)

Waffle Iron (339739) | more than 2 years ago | (#36338014)

and refused to consider any sort of cleaning system

That's partly because nobody knew at the time how to design an effective cleaning system which would: a) operate without water b) in a near vacuum c) on electrically charged dust, that d) was had enough reach to cover the large surface area of the cells, but e) fit within the rovers size and weight limits without f) jeopardizing the mission with its own added complexity and power requirements.

Maybe with years and years of operational experience, NOW they could design such a system. But as it turns out, they don't need to, because the occasional encounter with a random dust devil cleans them off just fine. So your whole fit of nerd rage regarding this issue is pointless.

Re:Non-units "holy war" thread here (1)

MichaelSmith (789609) | more than 2 years ago | (#36338872)

I think this shows that the Earth is one of the worst places to operate machinery. Rats get in and eat your wires. Rain gets in and corrodes everything. On Mars, or better yet, in space, a well built machine can keep operating for much longer than on Earth.

Re:Non-units "holy war" thread here (2)

ctmurray (1475885) | more than 2 years ago | (#36337594)

Politics of NASA and congress, I suspect led to the 3 month window. NASA could get funding for the launch and then 3 months of operation (where they were very sure these would last 3 months). Once you are on Mars AND the equipment is still running, then you can ask for and probably get more funding from Congress. In the same vein, if they die around 3 months or slightly after (for whatever reason) NASA can still declare the mission a success (and thus get future funding from Congress). Recall we had a string of Mars missions not working at all. So a short "estimate" is a win - win for NASA and its relations with Congress.

Re:Non-units "holy war" thread here (4, Insightful)

jd (1658) | more than 2 years ago | (#36337824)

Well, yeah. Can you imagine the response they'd have got if they'd asked for 7 years of funding? We'd still be waiting for the Rovers to be launched. They gamed the system because that's the only way you can make it work. Which is stupid because it's now impossible to truly evaluate a damn thing in high-end science, which means projects are not being funded according to their potential scientific value but according to how good the top brass are at out-politicking the politicians.

In order to get a proper, rational perspective on big-ticket science projects, Congress (and all other governments) have to recognize the value of risk and the importance of investing. It has to be possible for NASA to create a project - be it to go to the moon, launch robots to Mars, or sent probes to Pluto - that will take two or even three decades to run to completion AND be 100% guaranteed that it will be 100% funded from day one to completion.

At present, the only way that this works is by setting the original project so short that "completion" is damn-near inevitable and there's enough PR involved to make the actual work (via a follow-up) equally damn-near inevitable. That is NOT competent management, that's fraud by Congress (who deceive the public into thinking they're funding science) and fraud by NASA (who deceive Congress into thinking they're funding a PR stunt not science).

Congress HAS to fund NASA properly. A 5x-10x increase in budget would be a good start. Congress ALSO has to partially devolve NASA into a quango - neither the President nor Congress should have any power to hire or fire anyone at NASA, nor should they have any say over what projects NASA is involved in. There should be a charter (ie: a contract with the President) that states what the overall objectives should be over the lifetime of the charter, to which NASA can be held legally liable if they don't fulfull their side, and which states Congress' obligations in return, to which they also can be held legally liable.

One of the benefits of a quango type setup is that NASA currently can't own anything, it is currently obliged to choose a COTS solution even if they already have a solution (which would be GOTS) that's both cheaper and better, and it's required to opt for what is cheaper even if it is inferior, all because of government spending rules. If it were semi-private, government spending rules don't apply and government ownership rules don't apply. The problem with a fully private NASA is that it couldn't be government-funded at all, it has to be answerable to shareholders rather than independently-monitored objectives, and space research is expensive with little return on any predictable timeframe (if, indeed, there's any return at all). If it were semi-public, none of these limitations of private corporations would apply.

Many of the fiascos within the US government are as a result of trying NOT to use quangos but to have a hard division between the public and private sectors, with incredibly unhealthy ties and obligations between them, deception run rampant (as noted earlier), massive uncertainty and no coherent strategy. This might be highly desirable to those who hate the idea of "big government", but it is highly undesirable to anyone who likes "big science".

Re:Non-units "holy war" thread here (1)

aembleton (324527) | more than 2 years ago | (#36339072)

I like this.

This could be modelled in a similar way to the BBC where every 10 years it's charter has to go for review by politicians so that its plan for the next 10 years can be accepted. This could then include the funding that would be required for NASA to operate and then the politicians would have to keep their hands off it.

Re:Non-units "holy war" thread here (1)

cthulhu11 (842924) | more than 2 years ago | (#36340512)

Thank you for seeing what I've long thought was obvious -- basically the ol' "under-promise, over-deliver".

Re:Non-units "holy war" thread here (1)

theshowmecanuck (703852) | more than 2 years ago | (#36337804)

The first thought I had was infomercials. This is a 200 dollar value but you get it for 19.99; a more than 180 dollar savings. OK, so who said it was worth 200 dollars to begin with. Sounds like NASA hedged their bets in case it fucked up right away. Which lead to thoughts of software project management. Kind of like how software project estimates should work. Give management an estimate that is more expensive and too long and then brag when you come in under time and budget. Of course now-a-days pointy haired fucktards and project managers out to make a name for themselves give estimates too short and cheap and then force too few people from overseas to work too many hours to get it done on time; and fuck it all up. Then they blame the contractors and overseas slave labour, pat each other on the back and use each other as references in order to fuck up on another project. Good old business school grads, what would we do without you? But where were we? Oh yeah. Good on you NASA!

Re:Non-units "holy war" thread here (1)

excelsior_gr (969383) | more than 2 years ago | (#36338104)

Well, it was a lucky break, without the quotes. Sojourner lasted 3 months, so they set up to reach this target, and maybe even surpass it a little, which they did. As far as target setting goes (from the project managing perspective, not the engineering perspective), it was done quite by the book. From the engineering perspective, the initial estimate was that in three months time the martian dust would have covered the rovers' solar panels so that they would run out of juice, freeze up and die a little bit after that. Then, however something unexpected happened, namely a "cleaning event":
http://en.wikipedia.org/wiki/Cleaning_event [wikipedia.org]
This was unexpected because the thin martian atmosphere would not (so everyone thought) be able to lift the dust from the solar panels. Thankfully it is not so...

Concerning the budget, the rovers are actually getting *cheaper* as time passes and the mission gets extended. The most expensive part of the mission is getting the rovers on Mars in the first place. Thus, the dollar/sol ratio will keep getting smaller even if the mission receives several additional extensions.

You were however totally right in this point: Nobody will risk his neck and *guarantee* a lifetime of say, 3 years. Especially not when the last mission lived only three months. So, yes, this is a political issue, which is totaly ok if you ask me (just read Richard Feynman's report on the Challenger disaster to understant what I mean). Now, after having seen how it is like on Mars the year over, the threshold has been risen to a quite harder target than before. MSL Curiosity is planned to operate for at least 1 Martian year (686 Earth days).

I, for one, wish her luck!

Nothing to see here... (0)

Anonymous Coward | more than 2 years ago | (#36338302)

Cars have a short life estimation for example, and it's a mature technology where they should be able to properly estimate the true life span of these machines. However, if you treat a car right, it'll last far beyond even their most generous estimations. The same thing is happening with the rover. They've been showing some extra special love and tender care because it's not often you get to drive a robot around another planet successfully and analyze samples. The same can be said of human beings and other life as well. If you make it past your first 10 years without dying you're not likely to croak, excepting unusual circumstances. This was an even truer statement in the past when people were only living to 30.

Re:Non-units "holy war" thread here (1)

Kjella (173770) | more than 2 years ago | (#36339482)

The question is really what estimate you want, "best guess" or "worst case". If you say best guess half the missions would run shorter and half the missions would run longer, the problem is half would be considered a "failure" even if they did new and wonderful science. You'll never have the statistical basis to say if any probability is right, if scientists say this rover has a 80% chance of surviving 5 years we don't know if it's actually 20% or 2% or it's completely doomed, we'll never send enough copies to say.

That's why they want deliverables, things this rover will with almost certain probability deliver. The worst case estimate. Think about your computer, it might work for many, many years without problems. Would you like to guarantee that it'll work if we spend $100+ million dollars sending it to Mars? Hell no, because some of these fail. So you go over and triple check everything and finally promise that yes, this setup has been vetted over and over and it'll run 3 months without fail. If that's the 99% probability, it's no surprise the 50% probability is several years out there.

I was just going to say that ... (1)

PPH (736903) | more than 2 years ago | (#36339576)

... this is 0.84 times the highway distance from Ptghunk to Bazmaghbyur , Armenia.

Re:Non-units "holy war" thread here (1)

not-my-real-name (193518) | more than 2 years ago | (#36340096)

It's kinda funny. People complain when the project exceeds the estimates. People complain when the project crashes into the ground and doesn't complete any objectives. Conclusion: You just can't please some people.

Late-Breaking News from the Council: Onwards! (5, Funny)

Tackhead (54550) | more than 2 years ago | (#36337152)

The most Illustrious Council of Elders reports that last remaining mechanized invader from the blue world inexplicably refuses to yield as its brother did, and that our campaign against the invaders must therefore continue onwards.

K'Breel, Speaker for the Council, spake thus:

"Our red planet still basks in the warm afterglow of its recent V-S Day [slashdot.org] celebrations. V-S day marked the most recent victory in our campaign, but there still remains work to be done. Despite its wounds, the last remaining mechanized invader from the blue world continues to mark our red soils with tracks left by its foul wheels of terror."

When a junior tech guru for the Sacdot news service meditated on the fact that the campaign against the second invader has taken 29 times longer than the initial campaign estimates, and that during this time, the invader had 1.2 times the distance from the plains to the peak of our world's tallest and most sacred volcanic peak, K'Breel, in his mercy, had the guru's gelsacs - as well as the gelsacs of 503 of the tech guru's podmates - rendered unavailable for service.

(Speaking ex-councillo, K'breel was heard to have murmured "Connection reset? Meditate on THIS!" while applying varnish to the freshly-pierced gelsac of a junior cache server administrator.)

Re:Late-Breaking News from the Council: Onwards! (2)

Titoxd (1116095) | more than 2 years ago | (#36338224)

Heh, I was wondering what K'Breel was going to say about this. You seriously should put all of these in an eBook or something similar... if nothing else to ensure that all the gelsacs that have been sacrificed during the Blue Planet's invasion are memorialized properly.

Re:Late-Breaking News from the Council: Onwards! (1)

Anonymous Coward | more than 2 years ago | (#36339346)

Heh, I was wondering what K'Breel was going to say about this. You seriously should put all of these in an eBook or something similar... if nothing else to ensure that all the gelsacs that have been sacrificed during the Blue Planet's invasion are memorialized properly.

I'm just filling in for the late great TripMaster Monkey [slashdot.org], who started it [slashdot.org] in 2005, when, after a string of failed attempts by both NASA and Russia, Slashdot presupposed the existence of a Martian air force as a reminder that this really is rocket science, and K'Breel shortly followed.

K'Breel belongs to all of us at Slashdot. First to comes up with something decent on a Mars thread becomes the Speaker for the Council, and the first oxybreathing, DHMO-guzzling, bluesymp who does it poorly gets to eat his own gelsacs for lunch. :)

I hope they got the extended warranty (4, Funny)

zill (1690130) | more than 2 years ago | (#36337246)

That's 50 times beyond the roughly quarter-mile of roving distance initially foreseen.

I am deeply saddened by the decline of quality of recent American automobiles. Back in my days they built cars that lasted a lot more a quarter-mile.

There's not even a service center within 55 million kilometers for crying out loud!

Miles per gallon (0)

Anonymous Coward | more than 2 years ago | (#36338832)

Accounting for all the fuel it took to launch the rocket into space, what's the miles per gallon of fuel?

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