Curiosity: Destination Mars

[Dale O Sea]

I am sorry but this looks like so many places on earth I have been. It doesn't look right... I am with Adam from No Agenda. How is it that their cameras always capture part of the craft? They don't know how to frame a shot? (ok last one does not...)

Could be done for context, or to shoot extreme foreground to infinity for testing/calibration, perhaps?

And don't forget a bot is framing the photo, unless an operator is working with the 14 minute delay.

To me they look like the last bot's photos with a little variation in the terrain.

I need to check the site..

[Fan]

I somehow pre-replied to you showthread.php?postid=679623#post679623

[Fan]

I wonder what Jon Lear thinks of all this.

[Dale O Sea]

I somehow pre-replied to you showthread.php?postid=679623#post679623

Oops - was editing and didn't realize you replied or something..Seems I need to delete the duplicate.

It's easy to hit the edit instead of the quote button but I don't think I did that. I'll get my dupe..

[SquidInk]

http://igkt.net/sm/index.php?topic=4028

In the last few days some of the first high resolution color images of Mars Rover Curiosity's deck have been taken. These included some of the best images yet showing the knots visible on the exposed wire and cable bundles.

While a few of the folks here are no doubt aware, it might surprise most people to learn that knots tied in cords and thin ribbons have probably traveled on every interplanetary mission ever flown. If human civilization ends tomorrow, interplanetary landers, orbiters, and deep space probes will preserve evidence of both the oldest and newest of human technologies for millions of years.

[...]

Knot history buffs might find it interesting that a "Spot Tie"-like knot, with opposite Clove Hitch end orientation and topped only with a single half-knot was illustrated in 1917 by A. Hyatt Verrill under the name "Gunner's Knot". This was seemingly due to Verrill copying from J.T. Burgess, who had oversimplified "Bowling's" description of what possibly was the first known textual description of the Constrictor knot. But that's a whole different can of worms!

So why has NASA standardized on this knot instead others which might serve the purpose? The following reasons are merely my own musings. I'd be interested to hear others' comments on this knot's strengths and weaknesses.


* Conservative design

The Reef Knot and Clove Hitch are extremely ancient. Both were discussed in detail as surgical and orthopedic knots and slings by Greek physician Heraklas in the 1st Century AD. The Reef Knot is depicted with varying degrees of realism in ancient Egyptian statuary and hieroglyphics as far back as 4000-5000 years ago. I presume there would be little disagreement here that these two knots must be among the oldest of the purposeful, standardized knots used by humans. You simply cannot get more field-tested than this!

But why combine these two well-known old knots in a somewhat novel way that, at first, might seem a bit "belt-and-suspenders"?

* Even pressure

The inner profile of the clove hitch is smooth. Both turns bear on the bound object evenly throughout their contact. The contact area is increased by having two turns. When the reef knot is added, the ends are pulled up and away from the object. There is some extra pressure exerted by the reef knot on the riding turn, but this is distributed onto the two underlying turns. Evenness of pressure is important for the same reasons as the next item.

* Controlled tightening

Overtightening of cable management bindings can cause conductor breakage, insulation damage, excessive chafing, and deformations between the conductive, dielectric, and shield parts of a cable, and no doubt a host of other issues. It is one of the classic problems with ratcheting plastic cable ties (i.e. "zipties") that they only have quantized adjustment steps and cannot be easily loosened. While zipties with a metal tooth insert do allow for smoother tightening, the possibility of this tiny metal part coming loose near electronics generally excludes their use. That zipties cannot easily be loosened or adjusted during tightening makes them more prone to being left in an overtightened state. Difficulty of adjustment might also be considered a possible strike against using the Constrictor Knot (and similar knots) for this application.

The clove hitch is not known as a particularly good binder alone, but that may be an advantage in this application. If the clove is initially made too tight it is easily loosened and readjusted. Once the proper snugness is achieved the addition of the first half-knot produces only a small and predictable amount of additional tightening. One thing I did notice in my tests is that if the first half-knot is made in the opposite orientation than shown in the standard, it tends to produce more tightening and also separates the underlying turns of the clove hitch.

* Resilience to errors in tying

As mentioned above, I did some tests tying the knot incorrectly in different ways. While these forms generally seemed inferior to the specified knot, they were not obviously destined to fail. Using these two basic knots in a compound form seems to be a reasonable way to make errors of tying less detrimental to the resulting knot.

[Diogenes]

I wonder what Jon Lear thinks of all this.

Fan, he used to check in here - right???

Also don't hear him anymore on C2C.

[Doka]

Re: post 65

Oh look, Peperoni:D

[SquidInk]

Re: post 65

Oh look, Peperoni:D

They should have named it the 'Slim Jim Surveyor'.

[SquidInk]

[SquidInk]

http://orbitaldebris.jsc.nasa.gov/photo ... s.html#geo

The following graphics are computer generated images of objects in Earth orbit that are currently being tracked. Approximately 95% of the objects in this illustration are orbital debris, i.e., not functional satellites. The dots represent the current location of each item. The orbital debris dots are scaled according to the image size of the graphic to optimize their visibility and are not scaled to Earth. These images provide a good visualization of where the greatest orbital debris populations exist. Below are the graphics generated from different observation points.

Imagine Mars. No litter. Except a barrel full of landers, and assorted touch down gear... and a few dead satellites.

Ok, imagine Venus...

[SquidInk]

[SquidInk]

[SquidInk]

http://www.universetoday.com/98080/new- ... ndigenous/

Last weekend, the Mars Curiosity rover scooped out a few “bites” in the small, sandy dune known as Rocknest and inside the second scoop hole was a small, shiny particle, as we reported earlier. This speck – and others like it in the pit — is different than the previous object that looked like plastic and may have come from the rover itself. After some analysis, the MSL science team thinks the shiny particle is just part of the soil on Mars.

“As the science team thought about it more and more, the bright object is about the same size as the granules that it’s in and it is not uniformly bright,” said John Grotziner, MSL project scientist. “We went back and forth, and the majority of the science team thinks this is indigenous to Mars.”

[...]

One hypothesis that the specks are natural geologic material that might have a broken-off, flat surface called a cleavage that could be reflecting sunlight, making it appear bright.

The size of the bright fleck is about 1 mm, so it is “pretty representative of other objects there,” Grotzinger said, which range from half a millimeter to 2 millimeters.

Grotzinger said they will use the ChemCam instrument to take a closer look at the shiny specks. “We are going to shoot it with ChemCam, a remote sensing tool that has spectacular spatial resolution,” he said, “and aim it right on that fleck. Then we’ll aim it on another darker grain and try to decide if it is a different class of mineral.”

[Bobbi Snow]

I used iPhoto to enlarge the object; it's either a tiny little creature with big eyes, similar to a lizard... or it's a toy, someone from somewhere, left behind.

[Lore]

Curious things on Curiosity

http://www.space.com/17739-nasa-mars-ro ... hings.html