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Mars Rover Stuck in a Dune
Bamfarooni writes "The NASA Mars rover Opportunity has gotten stuck in a dune, buried up to the hubs of the wheels. While they haven't given up yet, it doesn't look good for the little guy who's now 359 days into the extended mission." From the article: "The Mars machinery had been cruising southward across the open parking lot-like landscape of Meridiani Planum, full of larger and larger ripples of soil. Opportunity has been en route to its next stopover, Erebus crater, nestled inside an even larger crater known as Terra Nova."
From TFA: Rover operators are optimistic they can extricate the robot from its jam, having gotten dug in before. and said Steve Squyres, lead scientist on the Mars Exploration Rover effort at Cornell University in Ithaca, New York. "We are very optimistic that we'll be able to get out of here, but we're really going to take our time doing it."
I'd hardly interpret that as "it doesn't look good for the little guy".
two rovers.... on opposite sides of the planet
As much as my Nerd Gene wants a manned mission to Mars, it's hard to argue with the scientific value of (relatively) cheap missions like this. NASA shifted in the late 90's to a series of relatively inexpensive probes with a narrow purpose (as opposed to the Voyager-class missions). These probes make sense. For one, there's less financial damage if one fails or is destroyed. And two, they can be put together, tested, and launched more cheaply and more quickly.
And we're getting some excellent science from them. The Mars rovers were an hour-by-hour news story, then a day-by-day news story, there was a lot of public interest in them during those first few days. These kinds of missions are, I think, more crucial to human space exploration than launching a dude to Mars.
There's some things you must have people in space to accomplish, but we've got a lot to learn yet through frugal unmanned space exploration and I hate to see so much of NASA's focus being shifted towards manned operations. Honestly, I hate to see NASA continuing to be involved in the production and operational side of space exploration. I think NASA should be reformulated as a primarily science and research-oriented organization and launch operations should be almost entirely privatized. NASA does too many things and most of it not that well, and none of it efficiently.
"I have never won a debate with an ignorant person." -Ali ibn Abi Talib
The rover is driving backwards so there is more to see in the front view than there is in the back view
I hope they get it out...
wot no sig
Actually you may be more right than you realize. Those with four-wheel-drive vehicles (that actually leave the pavement) know that sometimes after getting stuck, you can move the steering wheel from side to side as a way of trying to gain traction from the sides of the rut you're in.
Perhaps NASA could learn a thing or two from rednecks in 4x4 pickup trucks? *smile*
Actually, this shot from the Mars Rover site shows the front wheels pretty well buried and covered with caked-on soil.
Tracks are mechanically much more complex. Each track is mechanically linked with its neighbors, increasing the number of possible failures.
You can never go home again... but I guess you can shop there.
In order to even the wear on the drive motors on the rovers SteveS and crew have been alternating between driving forward and backwards.
6 wheels that are independent and can be moved up and down at will are better than a track system.
I am the Alpha and the Omega-3
Under near-ideal conditions, the rovers could crawl a hundred meters (three hundred or so feet) per day.
The two rovers are on roughly opposite sides of the planet, which has a diameter of nearly seven thousand kilometers. To bring the other rover around--assuming you could drive in a straight line and there were no obstacles or technical problems--would take two or three hundred years.
~Idarubicin
Not bigger wheels, bigger tires. Shoulda went with some 44" Baja Claws
No, you need sand tyres - mud tyres are designed to dig deep into the dirt.
That's the last thing you want to do if you are travelling across sand.
Vintage computer adverts: http://www.vintageadbrowser.com/computers-and-software-ads
When rain is relatively infrequent, as it is even in a "rainy" time in Southern Cal., the accumulated oils and guck on the road get churned into an emulsion by the passing wheels and create an extra-slippery mess that threatens control until a sufficient volume of water falls to float the crap off the road altogether.
Where rain is more frequent, the layer of guck is less and the danger less.
At least that's what my late buddy from southern cal. used to tell me, explaining why in a Virginia cloudburst he would pull over to the side of the road and refuse to budge until the initial fury was spent.
Letting the air out isn't urban legend. The purpose of letting *some* air out is to give the tire greater surface area to get grip. You're not deflating the tire completely, just taking out about 10-15lbs psi. Read it here.
Also, the floor mats do work, those people you see obviously don't know what they are doing with the floormats if they are ejecting them into the air. Don't floor it when you shove the mats under! You're suppose to just crawl it out using the floormats for grip instead of loose sand, or ice.
Live forever, or die trying.
[Source:" http://marsrovers.jpl.nasa.gov/mission/tl_surface
What will be learned from this information will help in future Mars missions, you gotta start somewhere!
He who knows best knows how little he knows. - Thomas Jefferson
Soyuz isn't more reliable - they have similar safety records, although the Shuttle's is slightly better (both craft have had two fatal launches, but the shuttle has launched more manned flights; more people have died on the shuttle, but that's because it carries more people).
Soyuz is cheaper - about half the price per kilogram as the shuttle. There are a lot of factors involved here, but as the previous poster mentioned, most of them have to do with it not being reusable. The downside to this is that they have to produce a new rocket each time, unlike the shuttle, and rockets have very large amounts of labor and raw materials (some materials, like those used in the engines are very expensive) involved in all of the part production and assembly. Even with the semi-mass-production style used on Soyuz, costs still add up fast, and there's not too much they can do to bring them down further.
Another thing that helps make Soyuz cheaper is that their labor costs are a small fraction the cost of ours. That makes the Delta-IV heavy all the more impressive as a launch vehicle, as its launch prices are similar to Soyuz and Long March prices, but we have to pay US labor costs.
Dear Lord: One of your creatures may be hurt tonight. Please let it be the other creature.
New Scientist has the story from about 2 weeks ago:
o rtunityAll.html#sol430
http://www.newscientist.com/article.ns?id=dn7284
"The rover has six wheels aligned in two rows and each of the four corner wheels has its own steering mechanism. The problem is with the front right wheel, which can still roll but is now stuck at a 7 inward angle. NASA rover project manager Jim Erickson says it is like a car losing its power steering."
It continues with a quote from the "Quote I wish I could take back" department:
"At this point, with this one actuator failed, it's an inconvenience, nothing more," says rover chief scientist Steven Squyres.
The JPL statement on the issue at that time is here: http://marsrovers.jpl.nasa.gov/mission/status_opp
[...]
"Opportunity's right-front steering motor stalled out on sol 433 during an end-of-drive turn. While performing tests to help the team diagnose the condition of that motor, the rover also continued to make remote-sensing observations. Testing in sol 435 did show motion in the steering motor, but analysis is still underway. The rover resumed normal science and driving operations on sol 436, but with restrictions on use of the right-front steering motor. It drove 30 meters on sol 437. Opportunity and Spirit are capable of driving with one or more steering motors disabled, though turns would be less precise. The latest revision in flight software on both rovers, uploaded in February, gives them improved capabilities for dealing with exactly this type of condition. It gives them upgraded ability to repeatedly evaluate how well they are following the intended course during a drive, and to adjust the steering autonomously if appropriate."
So the JPL story seems to say on sol 435 that the steering motor was still working, but testing was still underway and its use was restricted.
Final 2006 "Proof of Global Warming" US Hurricane Count -> 0