[X] My Assistant

[hendric]

Sorry! I mean Curiosity, the follow up to MER. It's currently being put together at JPL:

http://marsprogram.jpl.nasa.gov/msl/

[djellison]

Don't distract the guy, for goodness sake

[scooterlord]

Lol! Damn I was so excited for a moment... Thats ok though :/ I ll find my way through all this

[Pando]

If you look carefully to the pictures from rear hazcam and to the 'empty nest' pan (from James post), you will notice that the cables were going down from MER to the lander and are cut; the cut is near the retention mechanism and is probably made with a pyro system after landing (any further detail from someone more expert than me?)... I hope this can help you!

Awesome work, scooterlord. I've done 3d modeling in the past - oh my gosh, what you're doing is incredibly detailed and tedious labor...

To illustrate Dilo's point, here is an animation of the cable cutting process. There are several stages; some cables are cut when the rover gets up on its wheels. Others are cut after.

You can see 4 frames here - between frames 1 and 2 the rover gets up, and you can see that the cables on the right side are cut at this point. Between frames 3 and 4 the bundle is cut on the left side.



After the rover rises, you can see the pyro mechanisms where the cables used to connect to:



Here you can see some of the cable bundles going from the rover down to the lander. The big loop of cables that goes up and down is actually part of the lander.
http://photojournal.jpl.nasa.gov/jpeg/PIA04848.jpg

[scooterlord]

Very helpful post indeed!

But I also need a little guidance here. So, the pyro mechanism that cuts the cables is the thing on the left side on the animated gif with the holes? How exactly does it cut it? Since it's called pyro I suppose it burns it, but I need this info for modeling issues.

I mean are the cables cut INSIDE those holes? Meaning that no cables come under it after the rover leaves its lander?

Moreover I am having SERIOUS trouble making out stuff in the following image, if anyone knows what's going on, please draw a couple of lines and repost, I am staring at the 3 reference photos for a few days now and I can't gather enough information to start.. :/





Facts:

a) I know that from the front left side of the mer comes a 'fat' set of multiple cables, that connect somewhere at the rear. I think its the cable that goes round right in the middle of the red circle.

From other reference photos I can make out that to that white box at the left of the circle connect 3 cables, which I don't know where they come from. Plus, there is a cable wrapped arround it.

c) I suppose (but can't tell for sure) that all the cables from the HGA are joined into the fat set of cables that go towards the bottom-right side of the red circle and then are wrapped in foil and go to the right side of the mer.

What I am missing is information about the actual parts of the rover. For instance if I knew that this white box there is the 'HGA Controller' I would try to follow the cables routes from the HGA to this box. However I have no idea what that is!

Last, although I am working on this rover I also study reference from the other rover just to make-out the starts-ends of the cables, making it easier to predict their routes. Supposingly, in both mers the parts are the same, cables are connected to the same slots, and I assume that ONLY the routes are changed...

Looks like I am going to need an anxious month of studying before starting to actually model anything.

[MahFL]

The pyro is a small explosive, it pushes a sharp shear edge to cut the cables. Remember if they were not cut the rover would have been a lander, so the system have to be very very reliable.


http://exploration.nasa.gov/documents/repo..._From_Pyros.pdf

I had never seen that before....boom !

[scooterlord]

So, hm, cool

So, it is safe to assume that the holes are used for allowance to oxygen for the explosion to take place. Can someone please verify this?


If so, I'll get away with not modeling a few stuff

[Floyd]

Most explosive compounds (other than gas or hydrocarbons) do not need external oxygen. They often have NO2 groups in them that rearrange to give N2, CO2 and other components. Think of nitroglycerin. I don't actually know what type compounds are used for pyros, but sure they do not need external O2.

[Pando]

Speaking about pyros, I've marked up your image:

The metal piece in the yellow circle is the pyro assembly.
The cables going through the pyros are indicated by two pink lines (same ones that are on the right hand side in the animation being cut).
The red circle shows the trigger connections to the pyros, and they go where the red arrows are pointing. This picture shows them disconnected during assembly for obvious reasons - they are most likely connected at the very last stage of the assembly process.

[scooterlord]

Cool! So i understood correctly! If any of you happens to know anything about the cables at the rear side, please share!

[scooterlord]

Hello again,

I'm back and working on the rover with great excitement! Probably due to the fact I got a new pc and I can FINALLY open the rover file without any problems; I got an i7-960 with 6gb 1600Mhz Ram, so, work is getting done quite fluidly. It's the first time that I can merge the seperate files into one and actually SEE the whole model. 2gb of ram are consumed just to open the file. I started detailing the whole thing, progress looks really nice - as expected. Here are a couple of renders just to take a peek of what kind of detail you should expect in the final model. The shown models are modeling-wise finalized and only need texturing.





With the current pace of progress I might be done by the end of this year (hopefully!). It's a lot more work than I could possibly have imagined. About 5% of my brain will be released since I dedicate it to think of this project no matter what I am doing.

[hendric]

Let me be the first to say: Wow.

[monty python]

Just plain great!!

I think you'll finish about the time oppy makes it's first great discovery at endeavour crater.

[scooterlord]

Well, here I am, working at full speed providing with one more new render of the model-wise finalized mer idd. I will continue working to finalize each part step-by-step with full details before texturing. Here it is, comments welcome as always

[Phil Stooke]

Those ITAR agents are gonna be banging on your door any time now!

Phil