Chandrayan-2 Mission

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Mort Walker
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Re: Chandrayan-2 Mission

Postby Mort Walker » 02 Aug 2020 08:55

This is all very frustrating. The Chandrayaan-2 Orbiter has a high resolution camera and 3D mapping capability far better than NASA's LRO. Yet, we are still waiting to see high resolution images taken by Chandrayaan-2. There have been a few images, but nothing in detail. So what is going on here? You have internet sleuths pouring over NASA LRO images in the public domain and yet ISRO can't tell the world that Pragyan is intact?

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Re: Chandrayan-2 Mission

Postby chetonzz » 02 Aug 2020 13:48

=== deleted needless whine ===

Amber G.
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Re: Chandrayan-2 Mission

Postby Amber G. » 02 Aug 2020 22:37

सुखदु:खे समे कृत्वा लाभालाभौ जयाजयौ,
ततो युद्धाय युज्यस्व नैवं पापमवाप्स्यसि.

(Please use google translate or such other technique if your Sanskrit in rusty ..This is from Gita, basically it means , success/setback profit/loss or even happiness/sadness in cause of your duty are not that important)

the way ISRO has handled the landing failure is disgusting...all journalist in India who cry horse about freedom of expression, liberty, right to information, right to XXX and what not seems not even 0.001 % interested in this famous organisation behaving like USSR


I find this narrative of “failure”, “disgusting” associated with Chandrayaan and ISRO, quite strange, if not absurd.
And for those "journalists" who are claiming to "cry for freedom of expression" may like to educated themself, just a little bit in common knowledge in science, so that they do not sound so clueless. They sound like busy-bodies who call a gold medalist a "complete failure" just because she did not get 100% in the exam - just 99%.
****
I do not work for ISRO, but as a scientist I am so impressed with work they have done that 2 years ago, in a panel discussion , for my alma mater ( IITK) graduates, looking for job/career opportunities, I recommended ISRO as one of the good/exciting place to work for. They have done and are doing world-class work in so *many* engineering fields.

ISRO (or for any technical institute for that matter) science is ((or ought to be) a serious business, not some silly game to satisfy/humor silly ignorant ddm or people who do not even have a basic gasp of what it is all about.

Besides:
मुश्किलें कहते जिन्हे हम, राह की आशीष है वो.
और ठोकर नाम है, बेहोश पग का होश आना.

Rough translation:
Those things which we call difficulties, Are blessings along our way.
And stumbling is merely, The reviving of an unconscious foot.

Seriously : By most measures, Chandayaan 2 was quite impressive and successful. True, the landing was a failure - but that was what most knew (see my earlier messages in this thread - analysis *before* it all happened - I described how critical the landing part would be and I (and virtually all other scientists) were predicting the success rate of this part as very low. Please do read that.
------

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Re: Chandrayan-2 Mission

Postby Amber G. » 02 Aug 2020 23:00

Duplicate post deleted by author..
Last edited by Amber G. on 02 Aug 2020 23:43, edited 1 time in total.

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Re: Chandrayan-2 Mission

Postby Amber G. » 03 Aug 2020 00:12

Mort Walker wrote:This is all very frustrating. The Chandrayaan-2 Orbiter has a high resolution camera and 3D mapping capability far better than NASA's LRO. Yet, we are still waiting to see high resolution images taken by Chandrayaan-2. There have been a few images, but nothing in detail. So what is going on here? You have internet sleuths pouring over NASA LRO images in the public domain and yet ISRO can't tell the world that Pragyan is intact?


Mort - Frustration is understandable but it may really help to understand - quantitatively - what "high resolution" means.
As I posted long ago:
1 - This was by a joint effort - NASA's LRO/LROC's images are in public domain and thousands of people use it -- many were looking for Vikram. There were *many* reports/joint-efforts - people finding something "intersting" and other better experts looking it, verifying and confirming it.. slow process. These images were from October 15 flyby , and as I posted then it was likely to take months to go through all the millions of the images .
2 - It is quite *hard* to "identify" using images - very hard, difference is literally pixels - you can't really resolve it to see anything other than seeing a dot which was not there before.
3 - See <this> to see before/after images. Gives some idea why not everyone was able to see it right away.

CY2's OHRC has much better resolution than NASA's LRO/LROC but it is still of the order of 0.25 meters, and with poor lighting (sun very low, lot of shadows etc) the whole Vikram (Pragyan is even smaller) it still a few pixels.
And all this - the overhead position over the site - comes may be once a month due to the CY2's polar orbit - less opportunities for ideal sun location.

Of course, there are other ways than optically observe but optically I don't think one can tell much about the state of Pragyan/Vikram their damage etc. other than *very* rudimentary analysis. -- One can't really "see" Pragyan or its tracks other than presence of few extra before/after pictures comparisons, and CY2 wasn't there for "before" pictures (except for one pass just before Vikram separated).

ISRO, I am sure, has other (than optical or optics in visual spectrum) data - Radio transmissions (pings of Vikram/Pragyan may have lasted until the final moment, or may be even after the crash - or some other electrical activity - may be batteries exploded :) . Metal in Pragyan/Vikram signature etc. May be LRO (laser retroreflector) survived (if deployed - one can pinpoint Pragyan)

But, when all is said and done, perhaps the *exact* status (its damage etc) of Vikram is not that important, if it is not transmitting data. ISRO has millions of other photographs to study and learn. It would be nice if there is more data in public domain but even NASA (or any other organization in the world) LRO/LROC's data being public is exception rather than rule.
Like any other scientific discovery we have to wait.

(ISRO is there to do science - "satisfying" self-proclaimed journalists is not their job. I have not heard criticism from GOI or serious scientists or citizens about lack of transparency on ISRO's part)

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Re: Chandrayan-2 Mission

Postby Amber G. » 03 Aug 2020 00:24

^^^ The critical part, I don't think aam abduls understand is:

One (NASA/ISRO/Sleuths) can't really see/analyze Pragyan/Vikram in the traditional way as you see a google satellite image. All one "studies" is presence of extra dot / (or lack of dot - may be some rock got blown away) in before/after millions of photos taken at different time. .. Such discoveries may make news but scientifically not so important.
(If ISRO thought this was important, they could easily have put a 'black-box'' type beacon which could survived crash etc)

---
ISRO in a tweet has acknowledged the news which we are talking about - They say their experts are looking at these images.

--
Meanwhile NASA's LRO (Lunar Reconnaissance Orbiter) today makes its 50,000th orbit of the Moon!
Per their site:
- Camera - Taken 2.9 million images
- Thermometer - Made 524 billion thermal measurements
- Gathered 12000 TB of data.
(But most people really do not know/care etc... similarly CY2 is doing it's work without too-much fanfare..:) .

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Re: Chandrayan-2 Mission

Postby chetonzz » 03 Aug 2020 09:54

apologies for earlier emotional outburst...i had invested myself a lot in that mission from many years before that
see the video i made below, ecstatic even before they tried to land...

https://youtu.be/A6YGm2CZ9F8

anyway...Om shanti

now i only wait for CH-3 landing to happen hopefully before any new entity (govt/private) gets there

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Re: Chandrayan-2 Mission

Postby chetonzz » 04 Aug 2020 21:41

Interesting discussion going on at nasa spaceflight forum about the new landing theory...shan himself explaining things first hand...kindly visit for more

https://forum.nasaspaceflight.com/index ... 20324.1300

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Re: Chandrayan-2 Mission

Postby ramana » 05 Aug 2020 02:58

Don't bother. Any thing worthwhile ISRO will tell.

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Re: Chandrayan-2 Mission

Postby csaurabh » 05 Aug 2020 06:42

Amber G. wrote: - Camera - Taken 2.9 million images
- Thermometer - Made 524 billion thermal measurements
- Gathered 12000 TB of data.
(But most people really do not know/care etc... similarly CY2 is doing it's work without too-much fanfare..:) .


This is quite exaggerated.
A camera if taking images of 1000x1000 pixels at 30 frames/sec is outputting 30 million data points ( measurements) per second. If you leave it on for an hour, 100 GB of data would be collected ( assuming one data point is a byte, and it often is more ).
No one denies that TBs of data are being collected. The question is what are we doing with that data.

In the case of NASA, this information is put in the form of giant publicly query-able databases which can be used by scientists, researchers, and even amateurs - 'internet sleuths' like Shanmuga S. ( whom btw I have had the privilege of meeting and discussing this matter over lunch ). This isn't just for LRO, it goes for almost all astronomical data like Sloan Sky survey, Hubble telescope etc. While ISRO doesn't put anything in public domain to my knowledge just a few images for media purposes.

==modsnip==

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Re: Chandrayan-2 Mission

Postby Mort Walker » 05 Aug 2020 10:06

^^^That's exactly right. The CY2 optical resolution is good and in areas where there is good and bad light, there should be data that someone can sort through. If enough people get to see the data, and it doesn't have to be public, like colleges and universities across India, then you have enough eyes to look through all of it.

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Re: Chandrayan-2 Mission

Postby disha » 09 Aug 2020 10:53

chetonzz wrote:apologies for earlier emotional outburst...i had invested myself a lot in that mission from many years before that
see the video i made below, ecstatic even before they tried to land...


Nonsense.

ISRO shares its data. If they have data on CY2 lander/rover, it will share. Currently it does not have enough data. No point in sharing.

In India where the journos do not know the difference between Vigyan and Chandrayan, you cannot expect ISRO to hold a candle for DDM journos at best and traitors at worst.

As for your efforts you have lost nothing to even complain about. You just are in the me-me-me delusion and want attention waving your own flag and plugging your own youtube channel.

So please go with Om Shanti principal and stop your rants on FoE. You are welcome to move to China or Pakistan or anywhere else in the world if you think your FoE is curtailed in India.

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Re: Chandrayan-2 Mission

Postby disha » 09 Aug 2020 11:46

csaurabh wrote:So if Shanmuga, or someone else makes a claim, there is a publicly available source which can be used to verify it. The claim can easily be disputed- it is just a few pixels after all. But we have something to go on. When ISRO makes a claim, or doesn't make a claim, we have nothing to go on. you either believe them or you don't.


Problem with that approach is that ISRO will be spending valuable time and resources chasing ghosts. Tomorrow somebody will claim that CY2 landed 40 km away with is legs up for self aggrandizement (see above) and DDM will publish it since it does not know the difference between Vigyan, Chandrayan and Vidhwan. DDM cares about ad revenue. The more controversial it is, the more ad revenues it gets. So please understand the game plan. And here and all over ISRO, there will be demand to investigate that particular claim since the "data is from NASA".

I would ask you and the poster above Chetonzz to quote data from CNSA. Particularly cite photos from Chinese orbiter.

There is no doubt that the way ISRO has handled the fallout of Chandrayaan 2 has been appalling. The only statement that they keep repeating is - we have located the Vikram lander on the surface and posted this info on our website. That's it.


How? The mission was definitely not 95% success. It was 99% success. It does not take a genius to understand that this was the first polar landing attempted on Moon. And yes we failed on the lander mission while the orbiter mission was 100% success. If you do not have stomach for failures, then you should not be visiting this page at all!

Note, I was watching C2 in real time. I was positively surprised that we made it to a polar orbit of Chandra. If you really are keen to follow up objectively, please post here the issues that go into parking a satellite in the Chandra's polar orbit. Till then, the above statement of yours is noisy rants. Otherwise called rona-dhona. Wasting tremendous amount of bandwidth and time.

==modsnip===
Further, there is no hero worship of ISRO other than in your mind. ISROs fallacies have been brutally called out. Including on this forum. Further, all of the forum members, even die hard supporters of ISRO have a hearty laugh at the 'excellent' marketing skills of ISRO. Is ISRO lacking in several areas. Yes. Does ISRO have lacunaes. Yes. Is it striving to fix them? Resoundingly YES. In matters of science, only the last one counts.

As my job I get to observe quite a cross section of ISRO scientists, engineers and technicians. While there some brilliant and talented people there, they are a small minority. Most are content to have a 'govt job',


It is 80/20 rule. 80 percent in any organization are content to have a 'govt job'. The remaining 20% do the actual work. It could be 90-10 or even 99-1. But again it is quite arrogant of you to self appoint yourself in that Job. It is the chairman of ISRO's job and the job of DOS and the PMO and eventually the PM. If you have objective suggestions, send it their way. But please do not self appoint to a 'job' or a 'duty'. It sounds like you are commie!
Last edited by suryag on 09 Aug 2020 21:58, edited 1 time in total.
Reason: cleaned up irrelevant items

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Re: Chandrayan-2 Mission

Postby Suraj » 09 Aug 2020 13:32

Thread cleanup . You know who - please stop further interaction with each other .

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Re: Chandrayan-2 Mission

Postby chetonzz » 13 Aug 2020 17:53

first glimpse of Chandrayaan-3 assembly, slated for March-21

Image

Image

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Re: Chandrayan-2 Mission

Postby schinnas » 13 Aug 2020 18:09

Great suggestion by chetonzz and others for ISRO to make available the camera data to public domain after a few months lag so they get to see it first hand.

A huge number of open source Image recognition algorithms would be built on it by researchers and it would end up helping ISRO.

It is worth emulating NASA here.

Edited:
I was recently speaking to the CEO of a image recognition company in Massaland (funded by US DoD) that is making software to detect objects in runways from cameras so airports don't have to spend on humans for runway inspection 24*7.

With good ML models and data scrubbing, lot of valuable human effort can be avoided. ISRO can also demand that the image recognition algorithms and SW trained on its data are to be shared royalty free with ISRO.

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Re: Chandrayan-2 Mission

Postby Amber G. » 15 Aug 2020 03:40

Some excellent discussion, let me respond:
csaurabh wrote:
Amber G. wrote: - Camera - Taken 2.9 million images
- Thermometer - Made 524 billion thermal measurements
- Gathered 12000 TB of data.
(But most people really do not know/care etc... similarly CY2 is doing it's work without too-much fanfare..:) .


This is quite exaggerated.

Noting exaggerated. As clearly mentioned, that was from the official sources. I believe it.
(just read the sentence just above: viz "Meanwhile NASA's LRO (Lunar Reconnaissance Orbiter) today makes its 50,000th orbit of the Moon! Per their site:"
No one denies that TBs of data are being collected. The question is what are we doing with that data.

Very good question, I ask my self that too, that's why I, instead of just depending solely on DDM's or webforums I also
communicate with actual scientists. In my opinion (speaking as a scientist and objectively ) ISRO's is doing a fantastic job. (The very fact that CY3 is, what it is, is mostly due to good use of that data).

In the case of NASA, this information is put in the form of giant publicly query-able databases which can be used by scientists, researchers, and even amateurs - 'internet sleuths' like Shanmuga S. ( whom btw I have had the privilege of meeting and discussing this matter over lunch ). This isn't just for LRO, it goes for almost all astronomical data like Sloan Sky survey, Hubble telescope etc. While ISRO doesn't put anything in public domain to my knowledge just a few images for media purposes.


I never had lunch with Shammuga S. but I did have discussions over lunch with John Glenn (:)) - America's first man in orbit, and scientists like Prof. Carl Sagan (from his slide show(s) we - scientific community - often saw Mars photo before they became available to news papers and general public). (:) ) ..I also know, as it is common for most scientific community, many of ISRO engineers as colleagues / friends/students so I think I have better perspective than your average ddm. .. So let me comment on the issue of Vikram/Pragyan - and why ISRO seems to be not sharing everything. Obviously I don't work for ISRO and some of what I say below is speculation but I believe scientifically accurate and quite plausible.

-- LRO or CY2 ("even much better") camera is not that relevant. Whole Vikram would be, at best, a few pixels in low (about 20 degree or less) sunlight. Imagine:

Some nail clippings fallen in a vast forrest and you have a drone (with a very good camera) which [b]passes over this vast, hundreds of Km forrest -- may be once a month it happens to be over the right area ( the area is visible for few minutes.) [/b]

Sure, it is possible and believable (and indeed note-worthy) if someone (amateur), notices (after comparing previous photographs) a few extra pixels and discover those clippings.

This is quite challenging But even more relevant is the question " how important for ISRO to find the exact position where Vikram crashed"

It is NOT important at all - scientifically speaking. As I said before, one could easily have placed a blackbox type equipment, if it was *at all of value* (This would have been *very* easy to do).

We got all the telemetry and important data up till the last minute or so. CY2's orbiter is going around it's business to do it's mission and NO WHERE in the mission it was even remotely mentioned that CY2, in case Vikram crash landed, will find the spot.

Another example, suppose a missile launched from a AF fighter plane, missed the enemy plane, and a small piece of the missile, was discovered by armature locals. Do we use all our energy in blaming the AF (or our spy sats) that they were not able to locate all the broken pieces. May be locating every broken piece does not give meaningful data so we don't train our spy sat for that.

Hope this helps.

*****
Meanwhile, one of the exciting news was we (NASA) were able to shine a laser beam from earth on LRO (one of the external mirror) and see it's reflection back. We succeed after years of trying. It is hard to know the exact position of moving LRO to aim a laser in right direction and see the reflection coming back.

May be sometime in future, we will be able to "reflect" a laser beam from Vikram (or other such objects) and can locate such things from orbiter.

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Re: Chandrayan-2 Mission

Postby Mort Walker » 15 Aug 2020 03:59

^^^The larger question here is that images and data have not been released to the public from the CY2 orbitor.

It is not irrelevant that imaging of CY2 is better than LRO. Claiming to find Vikram, although it may not be the case, was at the same time not publicly dismissed by ISRO. Just make the CY2 data available for at least peer review in the academic community. What's the point of having a publicly funded space program when it can't provide the data publicly?

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Re: Chandrayan-2 Mission

Postby csaurabh » 15 Aug 2020 13:10

What is exaggerated is the idea that collecting TBs of data or billions of measurements is some kind of 'achievement'.
Like I said.. leave a camera on for a day or two and it will collect TBs of data.

Mort Walker wrote:^^^The larger question here is that images and data have not been released to the public from the CY2 orbitor.

It is not irrelevant that imaging of CY2 is better than LRO. Claiming to find Vikram, although it may not be the case, was at the same time not publicly dismissed by ISRO. Just make the CY2 data available for at least peer review in the academic community. What's the point of having a publicly funded space program when it can't provide the data publicly?


You got the point.
ISRO data is only shared with it's own labs and a few outside orgs like IUCAA. Not even IITs have access to it.
NASA data is shared with -everyone- (literally).

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Re: Chandrayan-2 Mission

Postby Amber G. » 19 Aug 2020 06:16

I find this *repeated* (ad absurdum) discussion about ISRO's CY2 not being able to "see" Vikram, or ISRO not "sharing" the data quite silly ir not laughable. Scientifically , for those who have, even rudimentary understanding of basic optics, or how things work in these kind of institutions , find the "analysis" of of resolving power of orbiter's camera , or power of "computer vision of somebody in "massaland" they know; quite laughable in context. Now we have some one claiming, amount of data, posted in clear technical terms on a MASA website is "highly exaggerated" simply because their camera has "terabytes of data".

So I will no further comment on that particular aspect.

ISRO and Indian Scientists do have a second to none capability about computer vision and AI to analyze images. The technology is repurposed in other sectors too ... I have seen many such reports. Here is recent story I posted in other brf dhaga.

.DST sanctions Rs 115 crores to IIT Jodhpur to set up tech and innovation hub

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Re: Chandrayan-2 Mission

Postby csaurabh » 19 Aug 2020 11:24

I find these repeated (ad absurdum) claims to authority quite laughable.

Crash course:
Images are taken by electro-optic sensors when EM radiation (light, IR, etc. ) falls on it when it is channeled through an optical train ( comprised of lenses, mirrors, differactive elements, etc. ) and this data gets transmitted and stored on Earth. This process usually generates massive quantities of data ( terabytes ) as anyone with a simple calculator can estimate and it is not some kind of 'achievement' to generate 'TBs of data'. The analysis of this data can be done either manually ( which used to be the norm previously, and still is used quite a bit today ), or with the help of computer algorithms (image processing/AI). The analyzed data is then conveyed to the stake-holders in order to make a decision (eg. to estimate the amount of flooding in an area ).

In the case of Earth-imaging satellites (called remote sensing), this enormous work is carried out not only by national organizations but nowadays mostly by private sector - both in terms of instrument development (to capture images), and in terms of processing and communication (eg. to advise farmers regarding their soil properties ). ISRO has only about 2-3% share in the global launch market and probably even less in the downstream market of image processing. So saying that they have second to none capability is quite dubious at best. In fact, a plethora of small companies and startups are currently emerging in India which directly analyzes commercial satellite data (available globally) and delivering it directly to farmers/fishermen/govt organizations, etc. ISRO is actually fading out of the picture here except for military related stuff.

Now coming to astronomical data. Generally speaking, no organization has so much time to analyze masses of astronomical data. Hence it is usually shared (for free) to various institutions and universities for them to analyze. There is nothing abnormal in that method. What is abnormal is when an organization keeps all the data to itself and then makes claims like 'we have found the lander but are not giving any image, just trust us cause we are DA BEST in this field'. It is nonsensical, and there is no other way to see it, really.

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Re: Chandrayan-2 Mission

Postby Amber G. » 22 Aug 2020 04:22

csaurabh wrote:I find these repeated (ad absurdum) claims to authority quite laughable.

I am sure you do.

No "claims of authority" but I do know physics, science and and my day job is pass that to new generation, I was simply trying to be helpful. But as they say.

अज्ञः सुखमाराध्यः सुखतरमाराध्यते विशेषज्ञः. ज्ञानलवदुर्विदग्धं ब्रह्मापि नरं न रञ्जयति
Hence will not waste any more time on this...
***
Meanwhile there was an excellent webminar and discussion with public by ISRO, so hope that those who were really interested in would have checked it out.. (Video, they said would be available on ISRO's official channel )
#Webinar on "Unlocking India's Potential in Space Sector"
Image
***

Meanwhile Congratulations ! Chandrayaan-2 Completes One Year In Lunar Orbit, All Scientific Instruments Performing Well: ISRO

Image

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Re: Chandrayan-2 Mission

Postby Amber G. » 22 Aug 2020 04:57

While heroes and experts here in brf are laughing at and giving 'crash courses' to us scientists, let me post a news story, as no one else has posted it -- Something India's PM mentioned it and even mainstream media has published it..
Anyway enjoy some of the best photos of Sarabhai Crater on his birth centenary.
Happy Independence day.

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Re: Chandrayan-2 Mission

Postby Amber G. » 22 Aug 2020 08:25

^^^Link for above:
https://www.isro.gov.in/chandrayaan-2-completes-year-around-moon

Highlights: Chandrayaan-2 lunar orbiter has finished one year and 4,400 trips around the moon — and the spacecraft is just getting started..

ISRO: "The spacecraft is healthy and performance of subsystems are normal, There is adequate onboard fuel to remain operational for about seven years."

The ambitious spacecraft has been busy since arriving in lunar orbit on Aug. 20, 2019. First, Chandrayaan-2 attempted to deploy the first Indian-led lunar lander, called Vikram. While that lander failed to touch down safely, the lessons learned from the attempt will inform the design of upcoming missions, ISRO has said. Meanwhile, the Chandrayaan-2 orbiter has continued its work above the moon.

After a year of operations, Chandrayaan-2 has mapped nearly 4 million square kilometers of terrain, a . One area of interest was the Balmer-Kapteyn basin region, which includes a "light plains" deposit of lunar soil, or regolith, on top of an older, basaltic surface. This zone shows the changes that occur after meteorites slam into the moon's surface; nearby areas have a clear impact crater system that generated the fresher shower of dust.

Chandrayaan-2 also spotted small-scale tectonic landforms called lunar lobate scarps. These structures are thought to be young features on the moon, but are often hard to detect due to their small size, according to ISRO. The agency highlighted one that the spacecraft imaged in October 2019 in the Mare Fecunditatis region. NASA's Lunar Reconnaissance Orbiter (LRO) has also spotted such small faults, which show the gradual contraction of the lunar surface as the moon cools from its formation some 4.5 billion years ago.

More generally, India's spacecraft regularly gathers high-definition imagery and science data concerning the moon's surface, which assist in interpreting geologic features — as well as in figuring out future landing spots for anyone designing a lunar mission. NASA plans to land people on the moon in 2024, and other agencies are also considering moon-landing programs, both crewed and robotic, in the coming years.

Orbital radars on Chandrayaan-2 are continuing to gather observations of lunar water ice at the poles — a possible resource for future missions. Mission officials are working with archival data gathered by LRO and Chandrayaan-1 and looking to better understand where and in what form water ice can be found on the moon.

"The first-year observations from Chandrayaan-2 demonstrate the in-orbit performance of payloads, strongly indicating its ability to contribute significantly to lunar science," ISRO added. "The anticipated long life of this orbiter can contribute much to the current resurgence of interest among the global scientific community for a sustained presence on the moon."

Some of the other investigations the spacecraft has performed include detecting signatures of argon-40 (confirming observations during the Apollo moon program of the 1960s and 1970s) and mapping the mineralogy of certain regions of the moon, such as Mare Tranquillitatis, an area that includes the first human moon landing site, where Apollo 11 touched down in 1969.

Chandrayaan-2 even indirectly monitors solar activity, providing additional observations for scientists trying to figure out how space weather affects Earth. On May 29, for example, ISRO reported that its spacecraft caught the sun shooting out the second-strongest flare of 2020 to date when Chandrayaan-2 captured secondary X-rays from fluorescence on the moon, as the lunar surface reflected the solar activity.

And ISRO is getting ready for Chandrayaan-3

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Re: Chandrayan-2 Mission

Postby Mort Walker » 22 Aug 2020 12:47

Amber G wrote:I find this *repeated* (ad absurdum) discussion about ISRO's CY2 not being able to "see" Vikram, or ISRO not "sharing" the data quite silly or not laughable. Scientifically , for those who have, even rudimentary understanding of basic optics, or how things work in these kind of institutions , find the "analysis" of of resolving power of orbiter's camera , or power of "computer vision of somebody in "massaland" they know; quite laughable in context. Now we have some one claiming, amount of data, posted in clear technical terms on a NASA website is "highly exaggerated" simply because their camera has "terabytes of data".


The issue is not one of resolving Vikram on the lunar surface or ISRO's capabilities. The issue is one of ISRO NOT disseminating data more widely outside of government organizations. The more this data comes out, the more the best and brightest youth of the country get excited to pursue careers in aerospace engineering and astrophysics. It also motivates the public and government to spend more resources on space exploration. Trusting the scientists, engineers and technicians at ISRO is a good thing, but "andha vishwas" is another.

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Re: Chandrayan-2 Mission

Postby Barath » 24 Aug 2020 07:29

There's an RTI request for an image of the Vikram lander. The response was that an image was acquired and that it is under processing. There was an order to provide more info once the processing is completed.

9 months later, no image and no further response. Does anyone believe that it is still under processing ?

ISRO is not even responsive to RTI, which is its obligation. Responses are grudging.

ISRO may share information for scientific purposes and with professionals/peers. But if it's mission ends there, it does not justify anywhere near the coverage, attention and focus it gets. Just cut the live national TV coverage etc

Inspiration, outreach and inculcation of scientific spirit for all Indians, young, old, professional, and otherwise is the justification. This needs to equally be a mission statement of ISRO, at least as it pertains to it's domain and activities. To it's credit,ISRO does do some of this. However the ways in which it does this would not be very out of place in the 1960s. And the priority, resourcing and effort are an afterthought. Except when convenient. And that insight and info disappears when inconvenient.

Dissemination and inspiration needs better resourcing, better spokespersons, better talent and infrastructure and a certain degree of independence.

It is far better to have , say, explained the process of failure analysis, and what the specific location of the lander can teach (or otherwise), than to actually proactively provide an image of the landing site. To do so would hopefully have inspired many more Indians on the scientific spirit, on engineering method, on rigor, and discipline to face up and try again. This would help unleash benefits far more than the direct ones, down the road.

And it would have set examples for government, public and private institutions on transparency, fortitude, and courage. It could have been wonderful.

Instead ISRO took another opportunity to miss out.

Historically Indian culture has not been short on power of thought, on philosophy, on education etc. But short on universal dissemination and potentially discriminatory rigor. ISRO could have done much more to help push that trend further in the opposite direction.

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Re: Chandrayan-2 Mission

Postby srin » 24 Aug 2020 16:33

Specifically on Vikram, it crashed, its mission is over. Pics don't matter. Location doesn't matter. I don't want ISRO to waste time on it.
The only reason Vikram matters is to ensure that necessary corrections are made to the CY-3 lander.

CY-2 orbital payloads' data is important. I don't know the ISRO policies here - how long they will have first access to the data before it is released, what the marketing process is (analyze the data internally, submit to journals and if it is breakthrough, update the media) and what their "anti-scoop" mechanisms are.

I'm still sore that the CY-1 MIP's water-on-moon was scooped by NASA's using the orbiter M3 data.

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Re: Chandrayan-2 Mission

Postby Mort Walker » 25 Aug 2020 00:49

srin wrote:Specifically on Vikram, it crashed, its mission is over. Pics don't matter. Location doesn't matter. I don't want ISRO to waste time on it.
The only reason Vikram matters is to ensure that necessary corrections are made to the CY-3 lander.

CY-2 orbital payloads' data is important. I don't know the ISRO policies here - how long they will have first access to the data before it is released, what the marketing process is (analyze the data internally, submit to journals and if it is breakthrough, update the media) and what their "anti-scoop" mechanisms are.

I'm still sore that the CY-1 MIP's water-on-moon was scooped by NASA's using the orbiter M3 data.


On the contrary. Failure analysis of the Vikram lander, how and why it failed, and methodology of the process is very important to CY-3 and other interplanetary missions. It wasn't the science that failed here, but it was the engineering. It's this engineering which makes the science possible.

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Re: Chandrayan-2 Mission

Postby disha » 25 Aug 2020 09:00

schinnas wrote:It is worth emulating NASA here.

Edited:
I was recently speaking to the CEO of an image recognition company in Massaland (funded by US DoD) that is making software to detect objects in runways from cameras so airports don't have to spend on humans for runway inspection 24*7.

With good ML models and data scrubbing, a lot of valuable human effort can be avoided. ISRO can also demand that the image recognition algorithms and SW trained on its data are to be shared royalty-free with ISRO.


To detect foreign objects on runways from cameras on the airport -> easy problem

To detect anything on the moon and classify it appropriately -> extremely hard problem.

The bolded part of yours is a vacuous statement. Nobody will create an IP using ML and make it public for free or give it to ISRO for free even if the underlying data is public. ISRO can keep demanding but by then its data would have been the proverbial horse that bolted the barn and all such demands are vacuous threats to bolt the door.

Since this is related to data and research: https://www.deccanherald.com/science-and-environment/light-from-young-galaxy-born-in-baby-universe-spotted-877338.html

Using India's very own space observatory Astrosat, a bunch of Indian researchers in collaboration with their partners from the USA, Europe and Japan on Monday reported spotting the signatures of one of the first galaxies that were born when the unive...

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Re: Chandrayan-2 Mission

Postby disha » 25 Aug 2020 09:05

Barath wrote:Dissemination and inspiration needs better resourcing, better spokespersons, better talent and infrastructure and a certain degree of independence.
...

Instead ISRO took another opportunity to miss out.



It is easy to say a cliche followed by a grand operatic statement.

I would want ISRO to release data slowly and deliberately and only after it is scrubbed and useless for other agencies unless of course it is already partnering with other agencies on specific well defined projects. There are several good reasons for that. Can you please name a good reason where I hold on to data from CY2? Just one good reason?

And for every one good reason to hold on to data, I will respond with two more good reasons.

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Re: Chandrayan-2 Mission

Postby idan » 25 Aug 2020 13:19

Chandrayaan-2's OHRC and NASA's LRO are completely different scientific payloads for different use cases. If people expect OHRC to return LRO like imaging then that is a wrong assumption. It is not a question of which camera is powerful, but both have different mission profiles.

OHRC was to provide high-resolution images of the landing site — ensuring the lander's safe touchdown by detecting any craters or boulders prior to separation. The images it captures, taken from two different look angles, serve dual purposes. Firstly, they are used to generate DEMs (Digital Elevation Models) of the landing site. Secondly, they are used for scientific research, post-lander separation. OHRC's images will be captured over the course of two orbits, covering an area of 12 km x 3 km with a ground resolution of 0.32 m. The other payload onboard CH-2, the terrain mapping camera (TMC-2) is optimised for stereo imaging with a wide field of view primarily to create 3D contours and can only generate meaningful data when there is proper illumination. OHRC is essentially a Ritchey–Chretien telescope with field correcting optics (RC + FCO).

Image
Chandrayaan-2 OHRC

IMHO, OHRC imaging is good for spot imaging of lunar surface and generation of DEMs and not sweeping imagery of large swathes of lunar surface in time-series. It might be difficult to pinpoint focus OHRC to the perceived crash zone of the Chandrayaan-2 lander due to orbital positioning, shadows etc.

Key Parameters of Orbiter High Resolution Camera:

Orbit altitude (km) 100
GSD (m) at nadir 0.25
Swath (km) at nadir 3
Spectral range (nm) 450–800
Stereo views - Fore and Aft in two consecutive orbits by spacecraft and maneuvering
Spectral range (nm) 450–800
Telescope diameter (mm) 300
Primary mirror diameter, D (mm) 300
Effective focal length (EFL; mm) 2046
Field-of-view (FOV, deg) ± 0.86

On the other hand, NASA's Lunar Reconnaissance Orbiter Camera (LROC) is a system of three cameras mounted on the Lunar Reconnaissance Orbiter (LRO) that capture high resolution black and white images and moderate resolution multi-spectral images of the lunar surface. LROC consists of two Narrow Angle Cameras (NACs) that are designed to provide 0.5 meter-scale panchromatic images over a 5 km swath, and a Wide Angle Camera (WAC) that provides images at a scale of 100 meters/pixel in seven color bands over a 60 km swath. The LROC is a modified version of the Mars Reconnaissance Orbiter's ConTeXt Camera (CTX) and Mars Color Imager (MARCI).

Image

1. LROC Narrow Angle Camera (NAC)

Image

2. LROC Wide Angle Camera (WAC)

Image

3. Mars Reconnaissance Orbiter's ConTeXt Camera (CTX)

Image

4. Mars Color Imager (MARCI)

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Re: Chandrayan-2 Mission

Postby srin » 25 Aug 2020 14:22

Mort Walker wrote:
srin wrote:Specifically on Vikram, it crashed, its mission is over. Pics don't matter. Location doesn't matter. I don't want ISRO to waste time on it.
The only reason Vikram matters is to ensure that necessary corrections are made to the CY-3 lander.

CY-2 orbital payloads' data is important. I don't know the ISRO policies here - how long they will have first access to the data before it is released, what the marketing process is (analyze the data internally, submit to journals and if it is breakthrough, update the media) and what their "anti-scoop" mechanisms are.

I'm still sore that the CY-1 MIP's water-on-moon was scooped by NASA's using the orbiter M3 data.


On the contrary. Failure analysis of the Vikram lander, how and why it failed, and methodology of the process is very important to CY-3 and other interplanetary missions. It wasn't the science that failed here, but it was the engineering. It's this engineering which makes the science possible.


On the contrary, I agree with you. It is important to ensure that Vikram defects are corrected in CY-3 lander and those learnings are institutionalized. ISRO has institutionalized learnings from failures of PSLV (shroud failure), GSLV (cryo engine failures) and CY-1, so there is no reason to doubt that Vikram issues haven't been thoroughly analyzed and resolved.

Then there is the issue of location of Vikram lander and RTI and related stuff. Absolute waste of time, IMHO. It'll probably help some well-intentioned busy-body get two days of fame, but I don't see it as being scientifically useful in the remotest way. Vikram can't be revived anyway, CY-3 with corrections is in progress - so what's the point ?

Then there is the issue of CY-2 orbiter scientific data. I don't want that to be in public domain before ISRO has been able to analyze it and claim any scientific discoveries that can be made with that.

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Re: Chandrayan-2 Mission

Postby Barath » 25 Aug 2020 21:18

I always thought location and orientation of debris provides datum for trajectory and that information can give some clues for failure analysis.
After all, you have telemetry only upto a point.

https://www.indiatoday.in/science/story ... 2019-09-11

ISRO hasn't been very transparent about the process. However, I haven't seen anyone independently analyze it from that perspective.

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Re: Chandrayan-2 Mission

Postby disha » 25 Aug 2020 21:33

This is prior to CY2 launch, however wanted to put this here:

https://www.sciencealert.com/nasa-s-found-a-lost-spacecraft-orbiting-our-moon

There's also the fact that our Moon is covered in regions called mascons, or mass concentrations, which have higher-than-average gravitational pull and have been known to tug a spacecraft out of orbit over time - sometimes even causing them to crash into the lunar surface.

So despite the fact that we last heard from Chandrayaan-1 while it was circling the Moon, after eight years of radio silence, there were no guarantees it was still there, and the orbiter had been classified as 'lost'.


Orbiting around moon is tough and CY1 was still orbiting more or less in same where it was last when we lost contact. That is remarkable.

And it is even more remarkable to put CY2 in polar orbit.

So questions for the members:

1. How many satellites are there in Moon's polar orbit?
2. Why would any agency hold on to data?

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Re: Chandrayan-2 Mission

Postby Amber G. » 25 Aug 2020 21:41

I have a challenge for @csaurabh ,@mort walker, @barath and others - who are lecturing and giving crash courses to us scientists and pontificating about ‘andh visvas’ and what not..

]Forget about Vikram, here is a simple “search” for an ordinary number (positive integer) – see if you can find it.

This positive integer, when you square it, multiply by 421 and add 1 to it, comes out to be a perfect square. Can you find this number?

(IOW find a positive integer n where (421 n^2 + 1) is a perfect square)

You are allowed to use all your resources, including computers and experts you know. This is an experiment to see how long does it take. I will wait for 2 weeks here.

(This is not particularly a hard problem, at least not for those who go for science / math /engineering a neither are mathematical tools use to solve such simple problems are hard…some may even use a computer to use brute-force (not unlike software comparing pixels to look for Vikram) . Though, I would not need a computer to solve it.)

Request to other folks, those who are mathematicians/scientists/engineers and find this problem easy here to hold off giving the solution for 2 weeks – they may give, say 2nd or 3rd digit of the answer but not the whole answer.
Last edited by Amber G. on 25 Aug 2020 22:24, edited 1 time in total.

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Re: Chandrayan-2 Mission

Postby Vivek K » 25 Aug 2020 21:57

^^^^ Amazingly offensive post - mine is bigger than yours type. I think that BRF hopes to be an open forum. Newbies are NOT disallowed from posting. So it shouldn't only be a forum for experts. What is wrong about wanting to learn about the fate of the previous mission to improve the chances of success of the next one? No one is attacking "us scientists". There is a whole group here that revels in bashing DRDO scientists but the ones complaining here never seem to take exception at that.

Definitely need to make the conversation more civil and inclusive here instead of being exclusive and discouraging civil debate.

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Re: Chandrayan-2 Mission

Postby Amber G. » 25 Aug 2020 22:14

srin wrote:Specifically on Vikram, it crashed, its mission is over. Pics don't matter. Location doesn't matter. I don't want ISRO to waste time on it.
The only reason Vikram matters is to ensure that necessary corrections are made to the CY-3 lander.

Precisely. Thanks for putting it so succinctly.
srin wrote:
On the contrary, I agree with you. It is important to ensure that Vikram defects are corrected in CY-3 lander and those learnings are institutionalized. ISRO has institutionalized learnings from failures of PSLV (shroud failure), GSLV (cryo engine failures) and CY-1, so there is no reason to doubt that Vikram issues haven't been thoroughly analyzed and resolved.

Then there is the issue of location of Vikram lander and RTI and related stuff. Absolute waste of time, IMHO. It'll probably help some well-intentioned busy-body get two days of fame, but I don't see it as being scientifically useful in the remotest way. Vikram can't be revived anyway, CY-3 with corrections is in progress - so what's the point ?

By design, Vikram had no RTG, it was supposed to have short life-time - (one solar day).. MAJOR (if not the singular ) scientific objective was -- ISRO wanted to test "soft landing", CY-2's ability to map the landing site, ityadi ityadi ..The "exact" landing place (as said before, if that was important they could *easily* place a beacon), how and which part will break in the crash may make tabloid talking point but is NOT science.

Then there is the issue of CY-2 orbiter scientific data. I don't want that to be in public domain before ISRO has been able to analyze it and claim any scientific discoveries that can be made with that.


I do not work for ISRO or have any connection other than having scientific interets/connection with some colleagues. I am a US scientist so can't speak for ISRO or influence their policy etc .. but FWIW ..*my impression* - in last few months, the willingness and amount of data shared by ISRO (and other GOI institutes / DST) even with joint India/US teams is really amazing -- Pandemic has taught people to work together as never before. Check out DST portals -- if you are a startup ,or a scientific institute, and have a valid reason, there are unprecedented ways and openness to request data. I don't know about CY2 orbiter data but Indian sat data (detailed maps etc) and be requested.

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Re: Chandrayan-2 Mission

Postby Amber G. » 25 Aug 2020 22:19

Vivek K wrote:^^^^ Amazingly offensive post - .

Vivekji - No need to get hyper, no offense intended. In fact, I invite you to post, the math calculation is simple arithmetic type.. No? Why not just put an answer.

Sincerely - Ignore, if you find learning "offensive". over and out.

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Re: Chandrayan-2 Mission

Postby Amber G. » 25 Aug 2020 22:42

Barath wrote:I always thought location and orientation of debris provides datum for trajectory and that information can give some clues for failure analysis.
After all, you have telemetry only upto a point.
.

"location and orientation of debris" if no other data is available may be of some value. Just like in a aircraft design data from wind- tunnel or data from instruments etc are much more helpful than debris.
Data from previous missions have mapped the gravitational map of moon very precisely.. the trajectory etc can be calculated *very* precisely and location/orientation really does *not* any scientific value. If it did, one would/could easily plan for it.

Hope this helps.

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Re: Chandrayan-2 Mission

Postby Amber G. » 26 Aug 2020 00:11

idan wrote:Chandrayaan-2's OHRC and NASA's LRO are completely different scientific payloads for different use cases. If people expect OHRC to return LRO like imaging then that is a wrong assumption. It is not a question of which camera is powerful, but both have different mission profiles.
Key Parameters of Orbiter High Resolution Camera:


Orbit altitude (km) 100
GSD (m) at nadir 0.25
Swath (km) at nadir 3
Spectral range (nm) 450–800
Stereo views - Fore and Aft in two consecutive orbits by spacecraft and maneuvering
Spectral range (nm) 450–800
Telescope diameter (mm) 300
Primary mirror diameter, D (mm) 300
Effective focal length (EFL; mm) 2046
Field-of-view (FOV, deg) ± 0.86


To add:

For those who are interested in scientific understanding may find this interesting..Those who find such post offensive please ignore.. here is some orbital mechanics in picture.. (Anyone can use well known tools to draw the following - the following is based on what I put here in brf last year... Nothing much has changed since then as far as basic orbits are concerned.

Image

Orbits: (Green LRO, other CY2). (Remember, moon surface below is spinning)

(Moon's North is thin vertical line - as you can see CY2's orbit is pretty close to exact polar orbit)

For example, LRO's recent image - approximately 900 million illuminated pixels are in the target area (about 1km x 1 km) .. each pixel is slightly bigger than a meter ([NASA/GSFC/Arizona State University has more details.).

ISRO's CY2 camera, is supposed to have a have a slightly better resolution but It is further than LRO's closest approach (which is about 50 km). I believe that CY2's slightly elliptical orbit is such that, it is slightly closer to the surface than average near the Vikram landing sight. .. As said before other conditions such as light etc are also a factor. In any case looking for Vikram is more complicated than many think,

Point is hope people (at least those who are interested in science) have some perspective.. how often CY2's orbiter passes over the target area (less than once per month or so)..CY2's object was *never* to analyze the crash site.


Hope this is helpful.

Added later: The orbits are calculated by me, so if there is an error (I don't believe there is any significant error) don't blame ISRO. The ephemeris ( data for current orbit) was taken from JPL/NASA/horizons's database.
ssd.jp..nasa.gov -- Revised: 2020-Aug-24 Chandrayaan-2 Orbiter Spacecraft / (Moon) -152


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