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Rough Roving: Curiosity's Wheel Damage 'Accelerated'
astroengine writes "Despite the assurances that the holes seen in Mars rover Curiosity's wheels were just a part of the mission, there seems to be increasing concern for the wheels' worsening condition after the one-ton robot rolled over some craggy terrain. In an upcoming drive, rover drivers will monitor the six wheels over some smooth terrain to assess their condition. "We want to take a full inventory of the condition of the wheels," said Jim Erickson, project manager for the NASA Mars Science Laboratory at NASA's Jet Propulsion Laboratory, Pasadena, Calif. 'Dents and holes were anticipated, but the amount of wear appears to have accelerated in the past month or so.' Although the wheels are designed to sustain significant damage without impairing driving activities, the monitoring of the situation is essential for future planning."
Dear Lord, Father in Heaven, we pray together for the safekeeping of Rover Curiosity's wheels. Although it may be a tool of science, and its discoveries a complete threat to religious doctrine everywhere, she is but a rover on a mission of Peace and Goodness. In your ever forgiving heart, please bless her wheels with durability and robustness.
Amen.
Half assed and built by the lowest bidder. Fucking america, I hate this country
And before the Nutters come in with their usual blather abound sending people, we can barely make WHEELS that survive going 2 miles per hour there! What makes you think we'll have life support machinery and food making equipment and housing and clothes that will survive for months there?????
As A poor young man driving a $500 '73 Ford Pickup, I remember carefully monitoring oil consumption, water level, and tread wear on the five dollar maypops I could afford to put on my baby's feet.
It is common knowledge that NASA has one initial too many for the Brobdingnagian budget, but I was poor as two Mongolian goat herders.
Happiness in intelligent people is the rarest thing I know.
Ernest Hemingway
I know weight is important and all, but .75mm of aluminium? Really? Maybe they should have less scientists over there at NASA and more people with common sense who can raise their eyebrows.
...the monitoring of the situation is essential for future planning
They mean when the rover is near it's death, they pause it, and send more rovers. After they get like 8 up there, they'll fight them, like on BattleBots. You know, get Mars ready for humans and their wars.
...the monitoring of the situation is essential for future planning
We all know that those rovers are up there cutting up large rocks and stacking them into pyramidal shapes that regulate the atmosphere in preparation for humans to arrive, only to try to cover up the pyramid's real identity so that the future race of beings don't know their real history.
...the monitoring of the situation is essential for future planning
obligatory future for this rover
Politics; n. : A religion whereby man is god.
Maybe Jade Rabbit can hop over to Mars and help Curiosity out...
they should not go with Pirelli...
Maybe they should have considered a AAA membership. Or I guess it would be MAA...
that gets you stranded in a bad neighborhood.
How far has this thing managed to go now? Couple miles?
Tires are stupid anyway. Hey, news flash, PhD eggheads... try these things called "tracks". I'm pretty sure they'll work on Mars.
NASA (and whatever monkeyshine outfit built this piece of shit) has too many Pee Haych Dees, and not enough people with mechanical skill and common sense.
Here's government for ya. A multi-billion-dollar whiz-bang rover with the world's best scientific equipment... off on the shoulder with a flat tire. Wonder how long it'll take Triple-A to get there?
That I'm right, and you don't like it, doesn't mean I'm a troll.
Comment removed based on user account deletion
"More wheels means increased contact surface, and greater wear rates."
Well, no.
The controlling variable with respect to vehicle mass vs. number of wheels is the pressure resolved on the wheel. Pressure is force/area. So having more wheels (of the same geometry, of course), means lower pressure loading, which means lower erosion. It can be a very nonlinear effect if the increase in load bearing area drops the pressure below a plastic deformation threshold.
From a simple wheel erosion POV, more wheels = lower erosion. From the whole mission engineering POV, it's much more complicated.
Hey, petty attacks aside, call us if you have the expertise and experience to safely land a 1-ton nuclear powered vehicle on Mars.
If not...you're still soooo cuuuute when you get all passive-aggressive in your little AC engineering armchair!
-JPL
In this age, whatever failure the other parties has met with is the lesson that one picks up.
The lesson whereby the failure of Nasa to better equip the Curiosity's wheels against abrasion / wear and tear may mean that the only country left on this world that has the will and the financial might to forge ahead with their space aspiration (China) surely benefit.
I bet if they are to send up any more space equipment (rover, dune buggy or whatever) they will put more emphasis on the parts that might face the issue of wear and tear / abrasion / friction.
Muchas Gracias, Señor Edward Snowden !
Maybe the wheels are just dirty?
They see me rovin'
They hatin'
The rover is designed to perform a certain mission for a certain length of time. There's no point in putting tires on it that outlast the instruments. Everything is designed to have roughly the same lifespan - so yea, the tires will be worn out by the end of the rover's mission. That's all they need.
I don't get all the people bashing the design?
Just think how long the rover has been on Mars - far longer than ever expected. It has a few dings in the wheels. Amazing machine!
Enjoy life! This is not a dress rehearsal.
selfies ?
Well, I was going to suggest you start an engineering career at NASA but the GP appears to have done that for me.
There's a cliche about being thought a fool, then opening one's mouth and confirming it. That applies here quite well: shut your mouth; we already know you're a fool.
Wasn't it "aerospace engineers" working in non-metric units that lost the Mars Climate Orbiter?
I don't think NASA would employ someone still working in inches.
From the reading I've done, it's met most of its objectives. Many of the goals and experiments don't need mobility anyway. It's not like it can't move either even with the existing and anticipated state of wear.
It does raise an interesting question though. Due to the cost of getting stuff there, should future missions include repair robots to reuse or recycle the stuff already on site?
Greed is the root of all evil.
Shoulda tested them on Minneapolis's potholes.
The MSL wheels are machined out of one solid billet, not made from sheet (just like MER and Pathfinder).
The problem with the 100 grams is that at the beginning of the project you have a particular mass budget, and it gets allocated into all the little smaller buckets, so that each team can go off and do their designs essentially independently: there's probably 10,000 people involved in making MSL, and some division into independent chunks is needed. You can't have the wheel designer calling up one of the people making a science instrument and saying "hey, can you give up 10 grams?". What's to stop the spectrometer guy asking for 10 grams from the wheels?
There's also a schedule issue: by the time you decide you need a heavier wheel, a lot of that other stuff is already built. MSL took about 4-5 years to build, it's not like lots of people were hanging around with nothing to do waiting for something. They were running double shifts to get it ready.
So at each step of the process, you take your best shot, and move forward.
As far as component sizes go.. There's standard design margins used, and you design on the basis of the expected loads (often for something that's not physically in existence yet, so there's some allowance for not hitting the target, as well). A lot of times, a structural member will be the size it is because it matches a bunch of other members, and it's easier to make them all 20mm rather than individually optimizing (not that they are interchangeable, but that means you can do a test or analysis once, which saves time). Same reason we don't make every resistor the optimum value, but use "standard values".
Insulation thickness on the wires are already at the minimum (that's an easy mass savings, and was taken out decades ago). It's not just the voltage rating, of course, but more about abrasion resistance and ruggedness during assembly. Solder formulations are chosen for reliability and process control, and I doubt that changing it would change the mass much. There is persistent talk about going to wireless interconnects to replace the substantial wire harness mass, but there's some untried technology there (parts that are radiation tolerant, non-deterministic links, potential EMI/EMC), and on a 1B+ mission, one tends not to take risks with the "infrastructure".
There are a lot of titanium parts on MSL, but some of those were exceedingly troublesome: acutator gear trains were changed from SS with wet lube to Ti and dry lube, and caused problems: http://www.thespacereview.com/article/1319/1
But ultimately, it's because it's a huge project, and you are inevitably going to have excess capacity/margin in all areas, to allow for the folks who burn their entire margin in theirs. Not every tradeoff is possible within the time constraint to get the darn thing launched.
Check out this gash/puncture taken from the mast camera. A whole set of images from the MAHLI "hand lens" camera on the arm, which lets them look under the rover. Lots of dents, and quite a few punctures. The ridges that form the treads seem to be holding out, though.
i'm amazed that Curiosity is still running on Mars. Modern technology is amazing. I thought Curiosity died. Or maybe I am thinking of another rover.
How far has the rover driven? A kilometer? Less?
Was the rover built by the lowest bidder?
Why are the photos from Chang'e 3 so dreadful in quality compared to these photos comingn all the way from Mars? Do the Chinese want their moon mission to look like it's using 20 year old camera technology?
Wasn't it "aerospace engineers" working in non-metric units that lost the Mars Climate Orbiter? I don't think NASA would employ someone still working in inches.
That old canard. NASA does everything in metric. They hired a subcontractor, some very popular these days among the anti-government groups. The contractor use imperial units. NASA engineers didn't realize until too late.
Given your description, Common Sense Internet Man has sight that comes out of his (be)hind.
Since he also should be a good oracle for SHA256 inversion in addition to all the other stuff you think he can do, you should be making a bundle in BTC right now, eh?
They've been planning a return mission for decades. A Mars sample return mission would be the most elaborate and expensive NASA had ever planned, not including new technology cost overruns which nearly doubled Curiosity's cost, and delayed it one launch cycle. The Mars exploration program was even terminated from NASA's budget last year as a punishment, untill partially restored.
The latest proposed sample mission would invovle three sub-missions; (1) A lander-rover to collect the rockets; (2) a lander-launcher to collect the samples and put them in orbit; (3) A third slingshot mission to retrieve the orbiter. This would involve less fuel weight cost than an all-in-one mission. We dont even have a powerful enough enough rocket to launch an all-in-one mission. A probablem with tis elaborate mission is more new technology to develop with unpredicatable cost. And more steps that could fail.
NASA and the space community classify proposed missions into three categories: (1) grand over $2B, (2) quick ($1/3B), and average (inbetween). They had about a hundred excellent missions of all kinds proposed in the most recent decadanal planning. But were unable to fund even a single grand, and just a couple average.
China may do it first.
He said five GRAMS, not five POUNDS. So that's 100g of additional fuel. Less than a kilogram. Even if it were pounds, 100 pounds of fuel is miniscule in the perspective of a 6.5-MILLION-pound[1] craft.
[1] - Saturn-V used for sake of argument.