Mars rover works its way out of crater

[JohnBoucher]

From MSNBC
It's easy to forget that these machines are performing as well as they are. Congrats NASA!!

[GaryVoshol]

Not bad for a 90-day project. It hardly seems possible that these are the same robots that started their treks back during the FLL Mission Mars game - the first year the Championship was held in Atlanta.

Good going.

[dlavery]

Actually, MSNBC jumped the gun a little bit (no surprise there). Opportunity is still within the boundaries of Victoria Crater for at least one more sol (Mars day). She is currently poised just inside the regolith ripple that defines the border of the crater. Tomorrow, if everything goes as planned, the command to drive forward across the ripple and out of the crater will be sent to the rover. She will basically follow the same path out of the crater that was used to enter. This will allow the science team to look back at the tracks left by Opportunity as she entered the crater a year ago, and examine them for changes, alterations, and environmental effects. After that, she will drive back out on the flats of Meridiani Planum, and begin the "cobble campaign" of investigations (probably starting Monday, if all goes according to plan).

-dave




.

[ATannahill]

Originally Posted by dlavery

...if everything goes as planned,... if all goes according to plan.

-dave




.

hmm is that a hint?

[Al Skierkiewicz]

Dave,
Considerable discussion over coffee has taken place about the lubricants used in the rovers due to the temperature extremes. Would you have anything to add?

[Andy Baker]

Originally Posted by Al Skierkiewicz

Dave,
Considerable discussion over coffee has taken place about the lubricants used in the rovers due to the temperature extremes. Would you have anything to add?

My guess is that they use materials with impregnated lubricants, or materials which naturally have high lubricity. Most likely, they stay away from grease or oil lubricants, as these can easily attract debris while also not be reliable after being in the vacuum of space for a while.

But that is just a guess. I would be very interested in hearing what is actually used.

Andy B.

[Elgin Clock]

Originally Posted by Andy Baker

My guess is that they use materials with impregnated lubricants, or materials which naturally have high lubricity. Most likely, they stay away from grease or oil lubricants, as these can easily attract debris while also not be reliable after being in the vacuum of space for a while.
But that is just a guess. I would be very interested in hearing what is actually used.

Andy B.

What about Graphite powder? That's a non-liquid lubricant, & very effective for unsticking things with repeated use, like car door locks for example... on Earth at least. lol

[Al Skierkiewicz]

Interesing ideas, but I am guessing that sample contamination plays into the spec as well.

[David Brinza]

Graphite isn't a good lubricant in vacuum. Absorbed water vapor and gas between the planes of carbon atoms in graphite makes it "slippery". Molybdenum disulphide (Moly-lube) is a much better dry lubricant in vacuum.

There are special greases that won't outgas or creep out of the mechanism. Finding non-contaminating lubricants that will work well at -100 degC (or colder) was a problem.

The specific lubricants that are used in the rovers probably cannot be disclosed publicly, due to export control (ITAR)* restrictions.

* Even though the rovers are not military in nature, the US State Dept considers space systems technical data to be sensitive information that cannot be disclosed to non-US persons without specific permission. (This is probably a topic for an entirely different thread).

[Carol]

Originally Posted by dlavery

Actually, MSNBC jumped the gun a little bit (no surprise there). Opportunity is still within the boundaries of Victoria Crater for at least one more sol (Mars day). She is currently poised just inside the regolith ripple that defines the border of the crater.

Are all of the Mars rovers female?

[wilsonmw04]

Originally Posted by Carol

Are all of the Mars rovers female?

Anything with wheels, wings, rudders, or thrusters are female. There are several reasons why that this. It's a tradition from the wet navy to name vessels after women. Someone once told me that robots are female because they tend to be ... temperamental. Being a nine year vet of wedding bliss i know that can't be true ;-)

[GaryVoshol]

"A ship is called a "she" because there is always a great deal of bustle around her; there is usually a gang of men about, she has a waist and stays; it takes a lot of paint to keep her good looking; it is not the initial expense that breaks you, it is the upkeep; she can be all decked out; it takes an experienced man to handle her correctly; and without a man at the helm, she is absolutely uncontrollable. She shows her topsides, hides her bottom and when coming into port, always heads for the buoys."

[JaneYoung]

Originally Posted by GaryVoshol

"A ship is called a "she" because there is always a great deal of bustle around her; there is usually a gang of men about, she has a waist and stays; it takes a lot of paint to keep her good looking; it is not the initial expense that breaks you, it is the upkeep; she can be all decked out; it takes an experienced man to handle her correctly; and without a man at the helm, she is absolutely uncontrollable. She shows her topsides, hides her bottom and when coming into port, always heads for the buoys."

I'm so glad to learn all of this. Esp. the part about:

...and without a man at the helm, she is absolutely uncontrollable.