Author Topic: Chandrayaan-2 GSLV MkIII NET January 30 2019  (Read 165468 times)

Offline vyoma

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Re: GSLV-MkII, Chandrayaan-2, NET 2018-Q1
« Reply #80 on: 01/14/2014 02:13 PM »
This is strange and strangely funny!
http://www.business-standard.com/article/pti-stories/isro-yet-to-pick-up-rover-built-by-iit-k-114011400882_1.html
Quote
ISRO had given a project to IIT Kanpur to develop a rover to be launched with Chandrayaan-II, which the university's scientists completed in 2010, but the space agency was yet to pick it up and make part payment to the institute, according to its professor.

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When asked about the possible reasons for ISRO not accepting the rover, Venkatesh [Prof at IIT Kanpur] said Chandrayaan-II was set to be launched in 2017, which could be why ISRO was not showing any haste in acquiring it.

Quote
According to him, IIT-K spent Rs 29 lakh on the project.

Offline antriksh

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Re: GSLV-MkII, Chandrayaan-2, NET 2018-Q1
« Reply #81 on: 01/14/2014 03:00 PM »
The 3 year timeline was also in part to ensure that GSLV has a had a couple of successful launches behind it before it launches something this valuable. Again, it depends..ISRO needs to really deliver wrt the GSLV program. And also the lander design fabrication testing going well. The 2016 target indicates the shortest possible time for the launch of Chandrayaan-2 if everything goes as planned.

From the latest pronouncements by ISRO, it seems more like the development of the lander is what's the main hurdle, rather than waiting for GSLV to be qualified.

Does anybody have any idea of what the Indian lander will be based on? Will it borrow from the Russian lander design, or will it be an all-original independent design? I'm assuming the former, since it's best to go with what works, but it's not clear how much Russian technology ISRO can get for this, or whether it's even seen as reliable following the Phobos-Grunt malfunction. What have the Chinese used?

« Last Edit: 01/14/2014 03:17 PM by antriksh »
Nasadiya Sukta:
Srishti se pehle sat nahin thaa, asat bhi nahin | Antariksh bhi nahin, aakaash bhi nahin thaa | chhipaa thaa kyaa, kahaan, kisne dhakaa thaa | us pal to agam, atal jal bhi kahaan thaa ||

From: 1st verse of 129th Hymn of the 10th Book of Rig Veda

Offline Star One

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Re: GSLV-MkII, Chandrayaan-2, NET 2018-Q1
« Reply #82 on: 01/14/2014 03:35 PM »

This is strange and strangely funny!
http://www.business-standard.com/article/pti-stories/isro-yet-to-pick-up-rover-built-by-iit-k-114011400882_1.html
Quote
ISRO had given a project to IIT Kanpur to develop a rover to be launched with Chandrayaan-II, which the university's scientists completed in 2010, but the space agency was yet to pick it up and make part payment to the institute, according to its professor.

Quote
When asked about the possible reasons for ISRO not accepting the rover, Venkatesh [Prof at IIT Kanpur] said Chandrayaan-II was set to be launched in 2017, which could be why ISRO was not showing any haste in acquiring it.

Quote
According to him, IIT-K spent Rs 29 lakh on the project.

How odd. So just have an unused Mars Rover lying about the place then?

Offline antriksh

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Re: GSLV-MkII, Chandrayaan-2, NET 2018-Q1
« Reply #83 on: 01/14/2014 04:17 PM »
Nasadiya Sukta:
Srishti se pehle sat nahin thaa, asat bhi nahin | Antariksh bhi nahin, aakaash bhi nahin thaa | chhipaa thaa kyaa, kahaan, kisne dhakaa thaa | us pal to agam, atal jal bhi kahaan thaa ||

From: 1st verse of 129th Hymn of the 10th Book of Rig Veda

Offline AJA

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Re: GSLV-MkII, Chandrayaan-2, NET 2018-Q1
« Reply #84 on: 01/14/2014 07:03 PM »

http://www.business-standard.com/article/pti-stories/isro-yet-to-pick-up-rover-built-by-iit-k-114011400882_1.html
How odd. So just have an unused Mars Rover lying about the place then?

Firstly, lunar, not Mars rover.
Secondly, some basic googling, sheds light.

1. The PI's Webpage at the IIT-K website.
I got this: http://home.iitk.ac.in/~adutta/4.htm

Quote from: Dr. Ashish Dutta
Traction control algorithm development and testing for Lunar Rover mobility system.
Funding: Vikram Sarabhai Space Centre, ISRO, Trivandrum, Amount: 8 Lakhs  (2009 - 2010)
 
Lunar Rover development for testing of vision based navigation and traction control algorithms.
Funding: IIT Kanpur, Amount : Rs 30 Lakhs  (2009-2010)

2. An IIT-K student magazine article detailing the work
The imaging and mapping system test setup uses a Logitech Webcam! :D I don't think they're flight qualified. The way they're going about mapping the terrain is interesting. Laser mapping, but not LIDAR. Wonder if they simply wanted to develop such a system, or if they did a trade-off analysis and found that the processing work required for this would've been lesser; perhaps this system's more autonomous and more robust; than one that performs image processing (and is perhaps trained on a limited data set)? Also wondering whether such a mapping system is envisioned with a dual purpose instrument in mind: could a LIBS laser (a la Curiosity) operate in a low power mapping mode, as well as a high-power science mode? Saving mass?

3. A post from this very thread showing a 6 wheeled prototype

4. An Indian Express article, that also offers some more details
Quote
Once the project is completed, we will test it on a prototype lunar rover at IIT-K and thereafter the technology will be forwarded to ISRO," added Venkatesh. The final testing and approval of all the components being developed by the IIT-K will be done by ISRO.
According to Potluri, of the six wheels of the rover, four can be driven and steered. The rest can only be driven.
"The six wheels will have 10 motors to manage the movement and steering of the lunar rover," he said, adding that the major challenge will be to bring a co-ordination between all the 10 motors.

--
So... there's no full-fledged rover gathering dust. But yeah, shizz like that does happen. Does anyone understand the logic behind a 3 year hiatus, once ISRO had started development; especially given that there's still so much work to be done before getting even a baseline design finalised. (This shouldn't really have been/be affected by schedule uncertainty).

But then again, the same thing can be said of IIT-K
Quote from: Business Standard article
The professor said his colleagues at the institute had realised that the project to build the rover, which would pick up samples from the Moon's surface and bring them back to Earth, would cost much more than Rs 7.5 lakh and had initially refused to take it up.

"However, the then IIT-K Director Sanjay Govind Dhande had insisted that the project would get the institute international fame and that IIT-K would pitch in with the money," he said.
So what happened? IIT-K achieve its international fame with other projects? They don't want Chandrayaan-2, anymore? :P

And before anyone asks: I don't think Chandrayaan-2 is designed to return samples. Atleast, I don't find anyone else saying that.
« Last Edit: 01/14/2014 07:04 PM by AJA »

Online sanman

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Re: GSLV-MkII, Chandrayaan-2, NET 2018-Q1
« Reply #85 on: 01/14/2014 08:09 PM »
Nah, sample return is Chandrayaan-3 -- not sure if they're waiting for that.

Offline chota

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Re: GSLV-MkII, Chandrayaan-2, NET 2018-Q1
« Reply #86 on: 01/18/2014 09:50 AM »
Rover Prototype
« Last Edit: 01/18/2014 10:11 AM by chota »

Online sanman

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Re: GSLV-MkII, Chandrayaan-2, NET 2018-Q1
« Reply #87 on: 01/18/2014 01:17 PM »
Yeah, I remember they even built some kind of lunar terrain chamber to test it in, too.

Offline vineethgk

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Re: GSLV-MkII, Chandrayaan-2, NET 2018-Q1
« Reply #88 on: 01/25/2014 08:19 AM »
News just in today from China says its lunar rover 'Yutu' has experienced an 'abnormality'. As usual, it doesn't say much about what exactly is wrong, but mentions it has got something to do with the 'complicated lunar surface environment'.

http://www.shanghaidaily.com/article/article_xinhua.aspx?id=196205

Maybe something for ISRO to watch out for in Chandrayaan-2 mission, considering that they had an unforseen heating problem for Chandrayaan-1due to reflected radiation from lunar surface?


Online sanman

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Re: GSLV-MkII, Chandrayaan-2, NET 2018-Q1
« Reply #89 on: 01/25/2014 10:56 PM »
How sad - the article says "mechanical control abnormality" - so I'm wondering if it's that pesky lunar sand. I hope that sand didn't get wedged into crevices someplace, or cause the rover to get stuck like NASA's Spirit (MER-A).

Offline antriksh

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Re: GSLV-MkII, Chandrayaan-2, NET 2018-Q1
« Reply #90 on: 01/26/2014 09:23 AM »
IITK Lunar Rover Proto. IITK was awarded to develop Lunar Rover development for testing of vision based navigation and traction control algorithms.
Nasadiya Sukta:
Srishti se pehle sat nahin thaa, asat bhi nahin | Antariksh bhi nahin, aakaash bhi nahin thaa | chhipaa thaa kyaa, kahaan, kisne dhakaa thaa | us pal to agam, atal jal bhi kahaan thaa ||

From: 1st verse of 129th Hymn of the 10th Book of Rig Veda

Online sanman

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Re: GSLV-MkII, Chandrayaan-2, NET 2018-Q1
« Reply #91 on: 01/28/2014 01:06 AM »
Very nice vids of the IIT-K rover.


---
Note: for those who can't play the FLV format, here's a page which tells you how:

http://atube-catcher.dsnetwb.com/video/How-Play-FLV-files-with-Windows-Media-Player.html

I followed the instructions, and everything worked fine. You could probably also just download VLC player, since that has every codec known to man.
---


Anyway, why are all those wires hanging off the front of the rover? Are things going to be that way for the final version?

How would this rover survive the cold temperatures of the lunar night? Is it supposed to have RTGs like China's does?

The Chinese rover seems to have suffered a problem with that infamously pesky lunar dust, which seems fine enough to get into every nook and cranny to gum up moving parts. How can this threat be addressed?

Maybe only Arthur C Clarke knows...
« Last Edit: 01/28/2014 01:07 AM by sanman »

Offline AJA

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Re: GSLV-MkII, Chandrayaan-2, NET 2018-Q1
« Reply #92 on: 01/28/2014 02:08 AM »
Anyway, why are all those wires hanging off the front of the rover? Are things going to be that way for the final version?

It's an engineering test bed! Cut them some slack for the aesthetics? :D

The Chinese rover seems to have suffered a problem with that infamously pesky lunar dust ...

Are you guessing, or d'you have a source that says the problem was because of the dust? AFAIK, they haven't told us what the issue was. I think the only information we have thus far is that the solar panels designed to fold back and prevent the rover from radiating away all its heat - isn't folding back. Check the Chang'E 3 thread.

Offline antriksh

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Re: GSLV-MkII, Chandrayaan-2, NET 2018-Q1
« Reply #93 on: 01/28/2014 02:42 AM »

Anyway, why are all those wires hanging off the front of the rover? Are things going to be that way for the final version?

How would this rover survive the cold temperatures of the lunar night? Is it supposed to have RTGs like China's does?

The Chinese rover seems to have suffered a problem with that infamously pesky lunar dust, which seems fine enough to get into every nook and cranny to gum up moving parts. How can this threat be addressed?

Maybe only Arthur C Clarke knows...

This is only an engineering prototype built by IITK to test the vision navigation and traction algorithms for lunar surface mobility. The R&D done by IITK will help ISRO in building the final versions of vision navigation and traction control subsystems of chandrayaan 2 lunar rover.

For thermal management of Lunar rover, I guess ISRO may use a system derived from the fluid circuits currently being developed for the crew module in the Human space program.

 

Basic info about IITK work on navigation and traction control algorithms:
Nasadiya Sukta:
Srishti se pehle sat nahin thaa, asat bhi nahin | Antariksh bhi nahin, aakaash bhi nahin thaa | chhipaa thaa kyaa, kahaan, kisne dhakaa thaa | us pal to agam, atal jal bhi kahaan thaa ||

From: 1st verse of 129th Hymn of the 10th Book of Rig Veda

Offline antriksh

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Re: GSLV-MkII, Chandrayaan-2, NET 2018-Q1
« Reply #94 on: 01/28/2014 04:16 AM »
Some info on thermal management of Chandrayaan 2 Lunar Rover

Thermal design planned to be adopted for the rover includes:
1) thermal flap (TF),
2) radiator windows,
3) warm electronics box (WEB) inside which most of the subsystems will be housed and
4) two passive thermal management units (TMU).

Power system of the rover comprises of a double-sided deployable solar panel, special Li-ion battery and power electronics. Double-sided solar panel is populated with triple junction (TJ) solar cells, realized on a 10 mm thick Aluminium (Al) honeycomb substrate, with CFRP (carbon fibre reinforced plastic) and KaptonŽ face sheets on both sides. The Li-ion battery and power electronics cards are mounted inside the WEB whose temperatures are controlled.

The top side of the rover chassis is provided with a motorized thermal flap consisting of insulation blanket/structure, which is closed during lunar nights to conserve heat inside the WEB. The sides of the chassis is insulated using multilayer insulation (MLI) structure called WEB and two units of TMU (8 W each) are mounted on the rover chassis inside WEB. Inner side of rover chassis (25 mm thick Al honeycomb) is provided with a highly conductive and thin 0.3 mm Al face sheet for electrical grounding

http://www.discovery.org.in/PDF_Files/du_20130703.pdf
Nasadiya Sukta:
Srishti se pehle sat nahin thaa, asat bhi nahin | Antariksh bhi nahin, aakaash bhi nahin thaa | chhipaa thaa kyaa, kahaan, kisne dhakaa thaa | us pal to agam, atal jal bhi kahaan thaa ||

From: 1st verse of 129th Hymn of the 10th Book of Rig Veda

Offline AJA

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Re: GSLV-MkII, Chandrayaan-2, NET 2018-Q1
« Reply #95 on: 01/28/2014 05:32 AM »
http://www.discovery.org.in/PDF_Files/du_20130703.pdf
Thanks Antriksh.


So the planned landing site is near the South pole (88 degrees S)? Very very cool. Props to ISRO if they stick with it - they'll be aiming to touch down  farther from the lunar equator than any other mission, including all the impactors, except our own MIP from Chandrayaan-1! For good reason too: the Aitken basin is a prime target for lunar geology. It'd be awesome to have contact measurements (as opposed to remote sensing only).


Quote
Thus,
the Chandrayaan-2 Rover solar panel may be expected to see temperature of Teq = - 182.07374 degrees C during the long (20 days) lunar nights at the landing site. And the solar panel temperature saturates soon after ~ 17 hours of lunar nights entry.


Worst case temperature
Quote
The solar panel temperature during lunar night, in this case, can be shown as Teq = 84.85949 K = -188.14051 deg C


Unfortunately, the paper only does a basic radiative (conduction isolated from rest of rover) heat transfer analysis to calculate minimum temperature during lunar night, and doesn't say anything about what is expected to happen to the uninsulated solar panel materials at such temperatures. Anyone have any data on this? They mention that panels on GEO satellites reach -169.9 degrees C during the 72 minute eclipse. But this is way longer than that. They don't calculate the range of temperatures either (i.e max temperature the array's likely to see during lunar day) - but mention that the surface temperatures stay between -160 & -120 degrees C


Btw, don't know if it's been linked before, but here's the Chandrayaan-2 page on the VSSC website: http://isrohq.vssc.gov.in/isr0dem0v2/index.php/science/science-history/74-general/1010-chandrayaan-2


Rover's carrying LIBS, and APXS; and orbiter will carry Large Area Soft X-Ray Spectrometer (CLASS) (How exactly did they arrive at the acronym? lol); Solar X-Ray monitor (XSM); L,S band SAR; IIRS, a Neutral Mass Spec.; and TMC-2.
« Last Edit: 01/28/2014 05:36 AM by AJA »

Offline chota

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Re: GSLV-MkII, Chandrayaan-2, NET 2018-Q1
« Reply #96 on: 01/28/2014 06:25 AM »
4 wheel Rover Bread Board Model  developed by ISRO (Final model will have 6 wheels)

> Semi-Autonomous navigation and hazard avoidance capability
> Elemental analysis of the lunar surface using Laser Induced Breakdown Spectroscope (LIBS) and Alpha Particle X-Ray Spectrometer (APXS) payloads
> Rover will be powered with a small solar panel
> Communicate to IDSN either through Lander Rover Communication System onboard the Lander or through the Orbiter Rover Communication System onboard the Orbiter

Photo Credit : ISRO

Offline antriksh

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Re: GSLV-MkII, Chandrayaan-2, NET 2018-Q1
« Reply #97 on: 01/28/2014 07:33 AM »
CH2 LR 4 wheels design

Can any one guess the Antenna Type? I have never seen T shaped antenna on any planetary rovers
« Last Edit: 01/28/2014 07:52 AM by antriksh »
Nasadiya Sukta:
Srishti se pehle sat nahin thaa, asat bhi nahin | Antariksh bhi nahin, aakaash bhi nahin thaa | chhipaa thaa kyaa, kahaan, kisne dhakaa thaa | us pal to agam, atal jal bhi kahaan thaa ||

From: 1st verse of 129th Hymn of the 10th Book of Rig Veda

Online sanman

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Re: GSLV-MkII, Chandrayaan-2, NET 2018-Q1
« Reply #98 on: 01/28/2014 08:01 AM »
Anyway, why are all those wires hanging off the front of the rover? Are things going to be that way for the final version?

It's an engineering test bed! Cut them some slack for the aesthetics? :D

Ah, I guess I thought that was the final product, or something.

I really hope they put more thought into the lunar dust problem.

Oh, and how are they going to tackle the ultra-low nighttime temperatures? Are they going to use RTGs as well?

Quote
The Chinese rover seems to have suffered a problem with that infamously pesky lunar dust ...

Are you guessing, or d'you have a source that says the problem was because of the dust? AFAIK, they haven't told us what the issue was. I think the only information we have thus far is that the solar panels designed to fold back and prevent the rover from radiating away all its heat - isn't folding back. Check the Chang'E 3 thread.

Sorry, I guess I should have linked to the article that I was getting my info from:

http://news.ninemsn.com.au/technology/2014/01/28/11/14/chinese-lunar-rover-cutely-broadcasts-own-death

Quote
Abrasive lunar dust is thought to be the cause of the rover's fatal breakdown.

Offline plutogno

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Re: GSLV-MkII, Chandrayaan-2, NET 2018-Q1
« Reply #99 on: 01/28/2014 08:15 AM »
Quote
Thus,
the Chandrayaan-2 Rover solar panel may be expected to see temperature of Teq = - 182.07374 degrees C

really?!? to the fifth decimal???