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by Vayutuvan
20 Sep 2019 03:00
Forum: Military Issues & History Forum
Topic: Indian Space Program: News & Discussion - Sept 2016
Replies: 3967
Views: 828341

Re: Indian Space Program: News & Discussion - Sept 2016

@Vayutuvan CY2 FF here. Cushioned landing vs. Inflated Parachuting? Why inflated balloon or parachuting to reduce speed is less better over say inflating a balloon (assume it is possible to protrude four legs with holes for the engine to thrust out [I just changed my thoughts for lack of tech knawl...
by Vayutuvan
20 Sep 2019 02:18
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 1981
Views: 213681

Re: Chandrayan-2 Mission

Sudarshan thanks for applying mind and not just saying its stable. From ISRO site: https://www.isro.gov.in/chandrayaan2-spacecraft The Vikram lander weight is 1471 kg. And from that graph of the Doppler returns the delta T was fraction of a second. So can you back calculate? I can recalculate with ...
by Vayutuvan
19 Sep 2019 22:39
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 1981
Views: 213681

Re: Chandrayan-2 Mission

FYI

before and after images from LRO of Beresheet at this Wikipedia page

https://en.m.wikipedia.org/wiki/Beresheet

we will have similar pictures had vikram crash landed. it gives hope that vikram did not crash land, may be.
by Vayutuvan
19 Sep 2019 13:04
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 1981
Views: 213681

Re: Chandrayan-2 Mission

A question: Do we know the spacing of the 500N engines on the lander? I am assuming they are mounted in a square configuration. square configuration with a center fifth engine is very stable.two diagonal engines and the anti-diagonal engines can be pulsed while the center engine is firing continuou...
by Vayutuvan
19 Sep 2019 12:55
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 1981
Views: 213681

Re: Chandrayan-2 Mission

^ It was done by US for the one if the Mars landers. I think spirit and opportunity but was given up subsequently what was done ? in anycase, who says we shouldn't do something similar with a variation? amreeka attempted and failed doesn't mean nobody else should attempt the same or attempt a varia...
by Vayutuvan
19 Sep 2019 12:46
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 1981
Views: 213681

Re: Chandrayan-2 Mission

No way ISRO is going to put up 32 cm resolution images to the public domain Images will be downgraded, such that public won't be able to see very fine details. But should be enough to keep us busy till the next launch 32 cm resolution, really?! If so, I don't care what ISRO does as long as it doesn...
by Vayutuvan
18 Sep 2019 09:14
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 1981
Views: 213681

Re: Chandrayan-2 Mission

wouldn't then be cheaper to have all air cushioned landing inside a big inflated ball [it ain't going up for sure] - say co2 or o2 is good enough for cushioning some spring loaded soft-joints to the the balloon periphery. it would also take care of any accidental tumbling etc (mechanicals). I guess...
by Vayutuvan
18 Sep 2019 02:24
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 1981
Views: 213681

Re: Chandrayan-2 Mission

SaiK wrote:math guru, perhaps we need to inflate it with something lighter than what is in moon's atmo.


That is the rub. Moon doesn't have any atmosphere. But that is also a blessing in that we require very little air to inflate the reticulated structure, assuming it is possible at all.
by Vayutuvan
17 Sep 2019 23:33
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 1981
Views: 213681

Re: Chandrayan-2 Mission

we can't use parachutes on moon, but we could use throw-away cushions. just thinking ahead on safety devices for the next landing. Increases the weight as well as the volume of the lander. That is why I was talking about a honeycomb structured metamaterial (with directional properties) skin on the ...
by Vayutuvan
17 Sep 2019 11:30
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 1981
Views: 213681

Re: Chandrayan-2 Mission

UB sir, both tangential and negative normal velocities are important. say normal velocity is zero. the vikram would have made a touch and go a few times and landed safely. I remember trying to skip flat pebbles in local watering hole.
by Vayutuvan
17 Sep 2019 11:22
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 1981
Views: 213681

Re: Chandrayan-2 Mission

Russian Luna 9 in 1966 was the first ever probe to soft land on the moon, it used landing bags thanks for the pointer. some folks dismissed these ideas as "flights of fancy". it all depends on the initial boundary value problem and the material properties of the material the balloon compl...
by Vayutuvan
17 Sep 2019 05:47
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 1981
Views: 213681

Re: Chandrayan-2 Mission

I realize this animation below concerns Mars, and things would have to work differently for the moon; but 'still and all' this shows the usage of those balloon/bags I mentioned above.... [youtube...]kSbAUtyO7xo[/youtube] Let us wait for a mech engr./materials scientist to weigh in on this. I don't ...
by Vayutuvan
17 Sep 2019 05:41
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 1981
Views: 213681

Re: Chandrayan-2 Mission

nraoji, ... which an algo/model trained on insufficient data will reject as match ... "trained" - that is the operating keyword. I don't think NNs/other machine learning mechanisms are fast enough. My educated guess is that they would not be using any heuristics as weak as NN/ML. Your sec...
by Vayutuvan
17 Sep 2019 02:27
Forum: Strategic Issues & International Relations Forum
Topic: J&K Union Territory-2019
Replies: 1983
Views: 244261

Re: J&K Union Territory-2019

vsunder wrote: ... Sharda Mukherjee was a stunning and elegant woman. She was a Maharashtrian woman. Later she became Governor of AP.


Bharathi Mukherjee, IIRC, was the Governor of AP. Of course, Sharada is a synonym of Bharathi or Saraswati.

(mea culpa, in light of vsunder's counter below)
by Vayutuvan
17 Sep 2019 01:11
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 1981
Views: 213681

Re: Chandrayan-2 Mission

... a number of gas generators would fire and inflate a whole cluster of air bags; as if encasing the lander in a bunch of balloons that would cushion and absorb the initial impact.[/url] What is the material the balloons are made up of? I bet some very fancy composite metamaterial is required. Rem...
by Vayutuvan
17 Sep 2019 01:01
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 1981
Views: 213681

Re: Chandrayan-2 Mission

... Tensorflow ... Most of the low-level code happens to be IMKL (Intel Math Kernel Libraries) if Intel processors are used. Other vendors have their LAPACK/BLAS libraries. Most image processing algorithms are linear transformations using small dense matrices. They are embarrassingly parallel. Tens...
by Vayutuvan
17 Sep 2019 00:15
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 1981
Views: 213681

Re: Chandrayan-2 Mission

^^^^^^^^^^^ Python supports Computer Vision. The entire mission relied on imagery scanned by the orbiter and even by the lander on it's way down. 'Crunching' that in real-time is a feat for Python onleee. Ravi garu, what do you mean by "support"? Any Turing Complete language "support...
by Vayutuvan
15 Sep 2019 23:12
Forum: Strategic Issues & International Relations Forum
Topic: Indo-UK News & Discussions- June 2017
Replies: 2356
Views: 350676

Re: Indo-UK News & Discussions- June 2017

So why not drop that narrative that they are Christian? Why the hypocrisy? They can modify their constitution what what old chap. Oh wait, they have no constitution - it is a tribal loya jirga.
by Vayutuvan
14 Sep 2019 10:59
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 1981
Views: 213681

Re: Chandrayan-2 Mission

any idea about at what scale that picture is? what is the 500 meter radius circle, for example? Don't remember exactly (I just copied/pasted from LRO's archive database of images .. but I can see Manzinus (C) , IIRC Diameter of that is 25 Km. ( Look around 70 S, add 22 E in Moon's atlas) That red c...
by Vayutuvan
13 Sep 2019 21:49
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 1981
Views: 213681

Re: Chandrayan-2 Mission

Amber G. wrote:For quick reference: Keep your eyes open..
[img...]https://miro.medium.com/max/615/0*_yEr9TO7nczK24uM[/img]


any idea about at what scale that picture is? what is the 500 meter radius circle, for example?
by Vayutuvan
13 Sep 2019 21:28
Forum: Strategic Issues & International Relations Forum
Topic: India-US relations: News and Discussions IV
Replies: 2690
Views: 402658

Re: India-US relations: News and Discussions IV

How successful have the Chinese 50 centers been? I once wrote an erudite note to the ‘newspaper of record’. It displayed originality and, if I may say so, a sophisticated intelligence. It was not published. That was my last attempt to provide a corrective. I also have not bought the paper since. &q...
by Vayutuvan
13 Sep 2019 11:22
Forum: Strategic Issues & International Relations Forum
Topic: India-US relations: News and Discussions IV
Replies: 2690
Views: 402658

Re: India-US relations: News and Discussions IV

Push back as in clever tweets? Aghast and appalled letters to the editor? A sins of the white man webpage in some corner of the internet? You need to be in a position to cancel a 100 aircraft order with Boeing, in favour of Airbus. That is the best form of conditioning. India is there. all four ave...
by Vayutuvan
13 Sep 2019 05:00
Forum: Strategic Issues & International Relations Forum
Topic: Indo-UK News & Discussions- June 2017
Replies: 2356
Views: 350676

Re: Indo-UK News & Discussions- June 2017

Unlike you, I am a little sceptical when it comes to perfidious Albion, even when that Albion in question is a man of the collar.
by Vayutuvan
13 Sep 2019 02:24
Forum: Strategic Issues & International Relations Forum
Topic: Indo-UK News & Discussions- June 2017
Replies: 2356
Views: 350676

Re: Indo-UK News & Discussions- June 2017

The primate's action might have had some meaning before it has become obvious to all that India will eclipse its colonisers with ease, and ascent to much greater things. I mean this with sincerity. "primate" " ha ha. you are evil my man :twisted:. good pun, that. Now The Primate will...
by Vayutuvan
12 Sep 2019 23:05
Forum: Strategic Issues & International Relations Forum
Topic: India-US relations: News and Discussions IV
Replies: 2690
Views: 402658

Re: India-US relations: News and Discussions IV

I am not sure how much is malicious. There is simply an uncritical, unthinking culture at play. Most probably. That is why I used to take notes so as to show them that they do not give a platform nor invite anybody from the other side when it comes to 'Hindu' India-'Muslim' Pakistan topics. That ch...
by Vayutuvan
12 Sep 2019 22:54
Forum: Strategic Issues & International Relations Forum
Topic: Understanding the US - Again
Replies: 3091
Views: 347447

Re: Understanding the US - Again

It most certainly will. But it all depends on whether US-Iran meeting at the highest level takes place and the outcome.
For China, NoKo is more important than Pakistan. My two cents.
by Vayutuvan
12 Sep 2019 10:58
Forum: Strategic Issues & International Relations Forum
Topic: India-US relations: News and Discussions IV
Replies: 2690
Views: 402658

Re: India-US relations: News and Discussions IV

Just FYI, we need to stop supporting NPR - let them know that we are not going to subscribe to PBS etc any more. And influence Nine (9) my strategy was slightly different. I used to give $10 every year. when they call me asking to give more, I would give them a earful and say that I will give lot m...
by Vayutuvan
12 Sep 2019 03:24
Forum: Technology & Economic Forum
Topic: Indian Autos Thread -2
Replies: 517
Views: 75132

Re: Indian Autos Thread -2

PV magazine is hot air. Pie in sky stuff which rarely sees any fruition. I would be very reluctant to believe anything they say. There is the potential for tenders and then actually issuing them and seeing who responds. Moreover, if there is only one responder to a tender, the tender is scrapped, I...
by Vayutuvan
12 Sep 2019 02:48
Forum: Strategic Issues & International Relations Forum
Topic: India-US relations: News and Discussions IV
Replies: 2690
Views: 402658

Re: India-US relations: News and Discussions IV

^ I understand that she might just have resigned. https://twitter.com/MihirkJha/status/1171826792602034176 Just how heard a news report on NPR from one aizaz Hassan. Both the anchor and mr. Hassan were panning the Indian army and civilian authorities. The reporter says there is "widespread&quo...
by Vayutuvan
11 Sep 2019 23:22
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 1981
Views: 213681

Re: Chandrayan-2 Mission

List of artificial objects on the moon

Look at how many crashed (unintentionally). This gives a better picture in terms of how after how many tries, each nation got it right. After one success, there were a string of failures as well.
by Vayutuvan
11 Sep 2019 09:33
Forum: Strategic Issues & International Relations Forum
Topic: Indo-UK News & Discussions- June 2017
Replies: 2356
Views: 350676

Re: Indo-UK News & Discussions- June 2017

eklavya wrote:^^^^
He’s a Labour politician, so he needed to score a few points off the Tory PM.


so why is he "impressive"? you haven't explained that (yet).
by Vayutuvan
11 Sep 2019 09:27
Forum: Strategic Issues & International Relations Forum
Topic: Indo-UK News & Discussions- June 2017
Replies: 2356
Views: 350676

Re: Indo-UK News & Discussions- June 2017

sorry to sound a sour note - the good archbishop is doing drama bazi. was he trained at Stratford upon Avon, I wonder. Canterbury tales are just tall tales so is this man prostrating.

French got it right - albions will be perfidious. It is their nature.
by Vayutuvan
11 Sep 2019 09:15
Forum: Military Issues & History Forum
Topic: BR Forum Feedback
Replies: 963
Views: 58520

Re: BR Forum Feedback

Dileep wrote:User Muns who created india-aware took it over. I am still helping them to work the ropes.

Please give your contact email.

are you there? is everything open to public or there is a guha, I.e. inner cave?
by Vayutuvan
11 Sep 2019 07:14
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 1981
Views: 213681

Re: Chandrayan-2 Mission

... AND had to operate maybe at the edge of the performance/instability envelope That is why Rocket Science is known as "pushing the envelope". :mrgreen: For example, just firing two rockets, hain jee? You need 3 points not colinear to define a plane, 4 points not in a plane, ..., n+1 poi...
by Vayutuvan
11 Sep 2019 07:11
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 1981
Views: 213681

Re: Chandrayan-2 Mission

Ashokk wrote:One of the DSN antennas in Madrid is being used for transmitting data towards the lander at 1 kb/sec @ 11kW. Data also being received... :eek:

What is the carrier frequency?
by Vayutuvan
11 Sep 2019 01:38
Forum: Strategic Issues & International Relations Forum
Topic: Understanding the US - Again
Replies: 3091
Views: 347447

Re: Understanding the US - Again

If I remember correctly, this ban was done by Shri Morarji Desai. Gautam No, it was the doing of Indira Gandhi. I am almost certain. Complete ban was imposed in 1978 during Morarji Desai's govt. Buth cutting down started much before. Here is something from NYT Export Ban on Monkeys Poses Threat to ...
by Vayutuvan
10 Sep 2019 23:26
Forum: Military Issues & History Forum
Topic: India's R&D in Defence DRDO, PSUs and Private Sector
Replies: 3767
Views: 503178

Re: India's R&D in Defence DRDO, PSUs and Private Sector

Saral (or admins), please edit the two posts you forwarded.

there are enough details in both the posts that I was able to narrow it down to a handful of companies, just from memory. If I do a casual google, V's identity would be known.
by Vayutuvan
10 Sep 2019 22:25
Forum: Military Issues & History Forum
Topic: India's R&D in Defence DRDO, PSUs and Private Sector
Replies: 3767
Views: 503178

Re: India's R&D in Defence DRDO, PSUs and Private Sector

It is a national level issue. Of not being able to provide world-class post-grad, phd & post-doc programs for the top students in this country. Take a look at this paper for instance, on IIT JEE Rank 1 students in the past 40 years https://www.currentscience.ac.in/Volumes/115/06/1017.pdf 30 of ...
by Vayutuvan
10 Sep 2019 22:16
Forum: Military Issues & History Forum
Topic: India's R&D in Defence DRDO, PSUs and Private Sector
Replies: 3767
Views: 503178

Re: India's R&D in Defence DRDO, PSUs and Private Sector

This from my current scenario and oftentimes I wonder if I made the wrong choice in staying back in the country . The only saving grace is the 1% who are genuinely nationalistic, technocratic Abdul Kalam types. Whole science and tech. ecosystem in India is held together by such people only. I am lu...

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