Help - Search - Members - Calendar
Full Version: MSL development & assembly
Unmanned Spaceflight.com > Mars & Missions > MSL
Pages: 1, 2, 3, 4, 5, 6, 7, 8, 9
Stu
They really should have someone in there at weekends...

Click to view attachment

laugh.gif
punkboi
The wheels are too big for skateboards, I'll give you that... wink.gif
Juramike
Three image composite view of MSL Curiosity and associated pieces and parts as of October 29, 2010 at 5:30 PM as seen from the viewing area.

Click to view attachment

MUCH higher-resolution image here: http://www.flickr.com/photos/31678681@N07/5138753408/
Den
Oppy's troubles with Purgatory show that MER's specific pressure on the soil is a bit high.
I tried to find more info, but so far unsuccessfully.
What is MER's specific pressure? Will MSL's one be lower?
djellison
sigh.... this has already been discussed. Pressure per unit area is not the be all and end all of mobility and traction.
Den
QUOTE (djellison @ Nov 8 2010, 04:22 AM) *
sigh.... this has already been discussed.


Either I am blind, or it is discussed not in this thread.

QUOTE
Pressure per unit area is not the be all and end all of mobility and traction.


As if I said it is... what's up with the hostility? I believe my question was quite innocuous.
Floyd
Den, you might want to see this old thread and Doug's response there. I found it by searching on "traction".

QUOTE (djellison @ Jan 16 2006, 10:58 AM) *
djellison
QUOTE (Den @ Nov 7 2010, 08:15 PM) *
I believe my question was quite innocuous.


Innocuous, oft repeated and discussed, and an oversimplification of the Purgatory event.
KrisK
Below, MSL's dynamic test model skycrane drop test. Great to see everything going as expected smile.gif
http://www.youtube.com/watch?v=YasCQRAWRwU

Question: Animation shows that wheels will be extended prior to the drop. But during the test it appears that they are to be extended after. Why is it different?
centsworth_II
Interesting. This video shows the wheels being extended even before the landing assembly is released from the back shell.
djellison
The animation is several years old and the deployment sequence has been changed since it was made - that's all.

An updated animation under production.
ElkGroveDan
... from Tuesday, hand-held with my phone so not the sharpest.
eoincampbell
QUOTE (ElkGroveDan @ Jan 20 2011, 07:48 AM) *
... from Tuesday,...

What's the giant spark-plug-looking thing?
djellison
The blue and white thing on the right? Handling mechanism for the stacked spacecraft - that's the drive that turns the thing to whatever angle they need to work on it.
Hungry4info
Very nice video showing the full motion drop test.
http://www.youtube.com/watch?feature=playe...p;v=YasCQRAWRwU
djellison
As linked to earlier today in this very thread, triggering the resulting discussion regarding the changed to the deployment of the mobility system.
Hungry4info
Ah, I apologise.
Mirek
Sample Analysis at Mars (SAM) by Paul Mahaffy from SETI Talks series YouTube video
RonJones
Does anyone know the status of the zoom Mastcam for MSL? I know the fixed focal length version was already delivered to JPL and probably has already been installed. Has anyone heard a cutoff date for the delivery of the zoom version in order for it to be considered by NASA/JPL to be used to replace the fixed version?
KrisK
I'm also very curious about status of MastCams with zoom lens. Still there is info on:
http://www.msss.com/all_projects/msl-mastcam.php
QUOTE
Status of Zoom Lens Cameras (2 identical Mastcams with zoom lens): Being fabricated at MSSS


Btw what is the mass of MSL's drop test model (recent skycrane drop test)? 1/3 of the mass of the flight rover?
Stu
More money needed for MSL...

http://www.spacenews.com/civil/110128-mars...-need-cash.html
MahFL
Yawn...that peice has enough, "proberblies, coulds, don't knows, virtualy no", to make it a waste of time reading.
disownedsky
QUOTE (MahFL @ Jan 31 2011, 07:40 AM) *
Yawn...that peice has enough, "proberblies, coulds, don't knows, virtualy no", to make it a waste of time reading.


I thought it was a good article, and it leaves me a bit worried about the funding picture for MSL. If you're looking for certainty, you live in the wrong universe, although clearly NASA, (like most other large organizations) needs to get much smarter about risk management. Part of it is that it needs to be OK when embarking upon something really ambitious, to admit you don't know what you don't know and that mistakes will have been made in planning. If you know what you are doing, then you are doing what know, which doesn't promise to take us very far.
SFJCody
I'm going to eat so many peanuts during EDL. As will many other UMSFers, I imagine.
nprev
Oh, I'll dutifully eat my peanuts...but in all honesty I'm growing more & more comfortable with the descent methodology.

Frankly, it looks riskier than it really is, IMO. Essentially the only difference here between a conventional powered landing such as those performed by the Vikings & Phoenix is that the payload is attached by strong cables to the powered section rather than bolted on, and those cables extend prior to touchdown. The same touchdown sensing occurs as in previous successful landings, but instead of cutting the engines it cuts the cables & sends the engines away for a distance. The advantages are the ability to land a much heavier load than what is possible with airbags, plus spare the payload the shocks of bouncing (which are pretty rough, BTW...on the order of 40g's.)

So...Most of my sweat will be over once we hear that the descent engines have started...not all, of course, but most of it. wink.gif
Explorer1
I had the same misgivings as well when I first heard the idea, it just sounds like so many moving parts that can fail. But if we just pretend those are elevator cables (which never snap like in fiction), and EDL will be as cool as a cucumber.
SFJCody
I'm fine with the method of landing, it's the importance of the mission and how devastating a loss would be that worries me. If I'm not mistaken this is the most expensive lone Mars spacecraft ever.
MahFL
QUOTE (nprev @ Feb 3 2011, 02:24 AM) *
....The advantages are the ability to land a much heavier load than what is possible with airbags, plus spare the payload the shocks of bouncing (which are pretty rough, BTW...on the order of 40g's.)...


I seem to recall the landing shock of the MER's was only 1 or 2 G's as per the engineering assesment. I believe everything was tested to 40 or so G's but the landing profile was not meant to impart that much force.
On second thoughts I might be getting mixed up with Phoenix Lander, which touched drown pretty softly....



centsworth_II
From: http://www.planetary.org/news/2004/0125_Op...__and_Sent.html
"By 9:05 p.m., Opportunity was bouncing on the ground in Meridiani Planum, landing with a relatively light impact force of between 2 and 3 Gs."
djellison
Those low G forces were unexpectedly at the soft end of a bell curve that extended to 40G. You have to design with the 40G in mind, because next time you might not be so lucky on the combined performance of chute / airbags / radar / surface / wind etc.

The MSL landing technique reduces the size of that bell-curve drastically.
MahFL
QUOTE (djellison @ Feb 7 2011, 03:54 PM) *
Those low G forces were unexpectedly at the soft end of a bell curve that extended to 40G. You have to design with the 40G in mind, because next time you might not be so lucky on the combined performance of chute / airbags / radar / surface / wind etc.

The MSL landing technique reduces the size of that bell-curve drastically.


I know you have to design with 40 G in mind, cause if it went to 4 G's and broke, you'd be kicking yourself in the backside for ever.
Also NASA HQ would not accept 4 G........
djellison
So your point of post 178 was.....?
centsworth_II
QUOTE (djellison @ Feb 8 2011, 09:59 AM) *
So your point of post 178 was.....?

If MahFL had not responded to the statement, "...the shocks of bouncing (which are pretty rough, BTW...on the order of 40g's)" , I for one would have been left with the mistaken impression that those were the actual forces experienced by the MERs.
djellison
I didn't get that impression at all. Meh.
MahFL
QUOTE (djellison @ Feb 8 2011, 03:59 PM) *
So your point of post 178 was.....?


I was just pointing out that the forces on bouncing were not 40 G but a relatively benign 3 or 4 G's. That was probably due to the excellent performance and timing of the of the retro rockets. So in future it might be argued that airbags work well, within the limits of thier design. Of course there is always going to be a day when your not so lucky.
dshaffer
QUOTE (RonJones @ Jan 27 2011, 07:23 PM) *
Does anyone know the status of the zoom Mastcam for MSL? I know the fixed focal length version was already delivered to JPL and probably has already been installed. Has anyone heard a cutoff date for the delivery of the zoom version in order for it to be considered by NASA/JPL to be used to replace the fixed version?


Does anyone have an answer to this?
ZLD
You could try contacting someone from the Mastcam science team. It may be something they wouldn't be willing to diclose at this time though.
Mirek
Looks like they have attached radiator for the RTG earlier today.

tharrison
QUOTE (ZLD @ Feb 10 2011, 07:12 AM) *
You could try contacting someone from the Mastcam science team. It may be something they wouldn't be willing to diclose at this time though.


I'm on the Mastcam science ops team at MSSS. All I can say is what it says on the website—the zoom Mastcams are currently under construction, and the FFL Mastcams have already been installed on the rover at JPL.
charborob
The MSL Science Corner webpage mentions this:
"In early 2010, NASA reconsidered the VFL [variable-focal length = zoom telephoto] cameras and work resumed on assembling these cameras, which will replace the FFL cameras described here if the work is completed in time and the instruments meet their requirements."
I don't know when the above sentence was written. My guess is that they have installed the fixed focal length cameras in case the VFL cameras are not ready in time or do not meet the "requirements". How much time would be needed to remove the FFLs and replace them with the VFLs? And what impact would that have on the rest of the assembly?
elakdawalla
If you check in on the Ustream webcast of MSL periodically you'll see that they are continuously assembling and disassembling the rover. Right now it's getting close to an assembled state because they're about to take it in for "shake and bake" testing, but after that I'm sure it'll get disassembled again. So even if the current incarnation of the MastCam is currently integrated into the rover, that doesn't mean it won't come off the rover again in the future; there are probably many opportunities to swap things out. Though obviously the sooner anything new can get integrated, the better.
djellison
QUOTE (Mirek @ Feb 10 2011, 11:15 AM) *
Looks like they have attached radiator for the RTG earlier today.


That's the mechanism used to put the RTG onto the rover - There is an engineering model RTG that I presume they're installing right now, to add some fidelity to the thermal-vac testing that's coming up soon. The radiators themselves have been there for a long time already.

tharrison
QUOTE (charborob @ Feb 10 2011, 01:28 PM) *
The MSL Science Corner webpage mentions this:
"In early 2010, NASA reconsidered the VFL [variable-focal length = zoom telephoto] cameras and work resumed on assembling these cameras, which will replace the FFL cameras described here if the work is completed in time and the instruments meet their requirements."
I don't know when the above sentence was written. My guess is that they have installed the fixed focal length cameras in case the VFL cameras are not ready in time or do not meet the "requirements". How much time would be needed to remove the FFLs and replace them with the VFLs? And what impact would that have on the rest of the assembly?


By the time NASA decided to reconsider the VFL cameras, the FFL Mastcams were already complete (and I think they had already been delivered to JPL at that point), so they've been installed on the rover since last summer. It shouldn't take too much time to physically swap out the cameras; the most time-consuming part would be any testing that they'd want to do once the cameras are installed on the rover.

Who knows, if the VFL cameras aren't completed in time for MSL, maybe NASA consider sticking them on the 2018 rover since they've already paid for them...

QUOTE (djellison @ Feb 10 2011, 06:33 PM) *
That's the mechanism used to put the RTG onto the rover - There is an engineering model RTG that I presume they're installing right now, to add some fidelity to the thermal-vac testing that's coming up soon. The radiators themselves have been there for a long time already.


Yeah, they installed the model RTG yesterday in preparation for launch vibration testing. The real RTG won't be installed until the rover gets to Kennedy.
PaulM
I asked Rob Manning: Why were there blue flashing lights Yesterday?

Rob replied: the blue light indicates that power is flowing, usually to the rover
the light can be hooked up to other systems in the room, too, like the descent or cruise stages

http://www.ustream.tv/nasajpl

EDIT: Thanks for the link below to the FAQ
elakdawalla
That's like the second most frequently asked question on the MSL UStream chat (after "what is this?"). Here's the FAQ.
Oersted
tharrison, I have a question. How are the zoom cameras designed "safety-wise", in case of failure of the additional zoom mechanism? Would a malfunction at that failure point lead the mechanism to revert to a usable fixed-focal-length mode? Or would it just be black curtain time? I guess what I'm asking could also be put like this: if the current doesn't flow to the mechanism anymore, will it mechanically revert to a usable state? As in, electricity flowing enables zooming, but if no electricity flows, a spring will push the lens back to a neutral usable fixed-length zoom.

djellison
If it fails - we end up with what's onboard the spacecraft now smile.gif
Oersted
A robust failure mode for a zoom-lens equipped camera will give it a better chance of making it onto Curiosity. If any conceivable failure will merely make the camera revert to a fixed-lens mode with no further capability degradation it would give the camera a much better chance of making it onboard, I should think. I'm sure James Cameron would agree. smile.gif
djellison
QUOTE (Oersted @ Feb 14 2011, 01:46 PM) *
A robust failure mode for a zoom-lens equipped camera will give it a better chance of making it onto Curiosity.


Actually - any changes right now would give it zero chance of making it onto Curiosity.
Oersted
Dear me, yes. I am asking about what is already in the camera, not suggesting changes! smile.gif
This is a "lo-fi" version of our main content. To view the full version with more information, formatting and images, please click here.
Invision Power Board © 2001-2014 Invision Power Services, Inc.