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by prasannasimha
31 Oct 2019 19:40
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 2274
Views: 341707

Re: Chandrayan-2 Mission

Just not making the orbiter will not cut it as to reach the moon the orbiter will be the system that will do the multiple orbiter elevation etc and then and only then can it detach and lander can land.
by prasannasimha
20 Oct 2019 00:58
Forum: Military Issues & History Forum
Topic: Indian Space Program: News & Discussion - Sept 2016
Replies: 4390
Views: 1066820

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

According to a AV report on Youtube[/url], very soon there is a going to be a landing test in Chitradurga in Karnataka. The RLV will be dropped from a height of 3 km by a Helicopter, the onboard system will then help this vehicle to glide and land on runway. That's good, but it would have been nice...
by prasannasimha
20 Oct 2019 00:53
Forum: Military Issues & History Forum
Topic: Advanced Medium Combat Aircraft: News & Discussion - 30 August 2019
Replies: 469
Views: 121328

Re: Advanced Medium Combat Aircraft: News & Discussion - 30 August 2019

To add to it IAF have clearly told they can track the so called Chines Stealth aircraft
by prasannasimha
06 Oct 2019 00:03
Forum: Military Issues & History Forum
Topic: Indian Missiles News & Discussions - 17 Dec 2018
Replies: 3841
Views: 1087977

Re: Indian Missiles News & Discussions - 17 Dec 2018

Not to worry. Nag is being used. We want other ATGM's to build up our stock and well we are not operating at present in hot summer when spie etc failed and now Nag works
by prasannasimha
03 Oct 2019 23:55
Forum: Military Issues & History Forum
Topic: Tejas Mk.1 & Mk.1A: News & Discussions: 23 February 2019
Replies: 3781
Views: 1135582

Re: Tejas Mk.1 & Mk.1A: News & Discussions: 23 February 2019

Tejas did travel from Bangalore to Jaisalmer for for Iron fist without refueling
by prasannasimha
03 Oct 2019 10:10
Forum: Military Issues & History Forum
Topic: Indian Space Program: News & Discussion - Sept 2016
Replies: 4390
Views: 1066820

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

One of the goals of SPADEX is also satellite refuelling and upgrading. Its not just about space stations.
by prasannasimha
30 Sep 2019 23:26
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 2274
Views: 341707

Re: Chandrayan-2 Mission

Oh so you are insinuating that ISRO has already located Vikram/Pragnya? There is already mention of thermal imaging .There are sources mentioning that imaging by the orbiter has been done. Further information will be got after failure analysis. They will not put out any more information till it is ...
by prasannasimha
29 Sep 2019 23:47
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 2274
Views: 341707

Re: Chandrayan-2 Mission

Thanks, makes me feel better. It makes sense, so they can also do comparative before and after analysis. I think ISRO has all the pics, analysis (finding needle in hay stack) is taking time and thus not officially released. The shadows etc. only came some days after the 'landing'. Trying to find 3 ...
by prasannasimha
29 Sep 2019 22:55
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 2274
Views: 341707

Re: Chandrayan-2 Mission

To put it into perspective the expected image even of the CY2 orbiter would be 3 pixels wide and that of LRO 1 pixel in size. The shadow analysis may give more information. As Amber G said it will require comparing of before and after images.
by prasannasimha
29 Sep 2019 14:24
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 2274
Views: 341707

Re: Chandrayan-2 Mission

UlanBatori wrote:This thread is now more repetitive than an orbit by the LRO. As long as nothing new is discussed v should b fine. Maybe post a few pics of the launch?

Then please desist from posting if noncontributory
by prasannasimha
27 Sep 2019 14:48
Forum: Strategic Issues & International Relations Forum
Topic: Kerala, Andhra and Tamil Nadu - news and strategy thread
Replies: 1734
Views: 245270

Re: Kerala, Andhra and Tamil Nadu - news and strategy thread

If this caste based bashing does not stop pronto bans will be issued. Be warned. This forum is Bharath Rakshakh were we talkand promote unity and not create anecdotal fables. This page will be monitored.
by prasannasimha
26 Sep 2019 21:37
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 2274
Views: 341707

Re: Chandrayan-2 Mission

What is 360 degree flip? If you see the image during the landing the animation showing the position of the lander actually did a Vishnu chakra type of somersault 360 deg rotation back to its vertical position and righted itself (I immediately commented as to why it was doing such a flip) but there ...
by prasannasimha
26 Sep 2019 07:52
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 2274
Views: 341707

Re: Chandrayan-2 Mission

Gyroscopes could have had a Gimbal lock FWIW The rotation loop completed the 360 Deg flip as seen from telemetry but during the flip it rapidly descended leading it to try to fire to decelerate for given altitude. Now we had only 2 engines on which does not have enough theust. So engine valiantly tr...
by prasannasimha
18 Sep 2019 09:28
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 2274
Views: 341707

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
by prasannasimha
16 Sep 2019 12:37
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 2274
Views: 341707

Re: Chandrayan-2 Mission

The main mission whichis the orbiter is still going on and data as usual will be released in two tranches. First release is for ISRO and Indian researcherd. After 6 months data is released for any scientific use after registration with ISRO. Both MOM and ASTROSAT data are beingreleased in that forma...
by prasannasimha
15 Sep 2019 22:57
Forum: Mil-Tech Archive
Topic: Naval Tejas Mk1/Mk2: News & Discussion - 23 February 2019
Replies: 688
Views: 181965

Re: Naval Tejas Mk1/Mk2: News & Discussion - 23 February 2019

The arrestor cable is meant to be able to resist and is not a single fiber but a rope with multiple strands. Not easy to break. Suspension bridges are "suspended' using these.The breaking forces etc are well known.
by prasannasimha
15 Sep 2019 12:06
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 2274
Views: 341707

Re: Chandrayan-2 Mission

They will not release detailed images as this will give an idea of our 2 point discrimination capability. May be a later degraded image. The orbiter is working very well. Why would we want to hide any enhanced camera capability? This is being used on the moon to enhance the knowledge of humanity......
by prasannasimha
15 Sep 2019 10:58
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 2274
Views: 341707

Re: Chandrayan-2 Mission

Vikram’s quiet because it can’t talk! But Isro? What to write when there is no further info. They are trying to communicate and its not connecting. Everyone knows that. They will not release detailed images as this will give an idea of our 2 point discrimination capability. May be a later degraded ...
by prasannasimha
12 Sep 2019 00:55
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 2274
Views: 341707

Re: Chandrayan-2 Mission

I think somewhere now the Chandrayaan Orbiter would have made a pass over the putative crash site . Leet us hope we get some more useful data about it. I do not think we will get images from the orbiter wrt the lander so easily as it may give an idea about our two point discrimination capability or ...
by prasannasimha
12 Sep 2019 00:51
Forum: Military Issues & History Forum
Topic: INS Arihant: News & Discussion
Replies: 387
Views: 126571

Re: INS Arihant: News & Discussion

^Nothing that is released would be Inadvertent- it would have been done on purpose
by prasannasimha
11 Sep 2019 23:03
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 2274
Views: 341707

Re: Chandrayan-2 Mission

I am still trying to understand how the lander is intact. For this to happen, it had to slow down considerably from the time of the anomaly. That can only happen if the lander is right side up for most of the rest of the descent. I am more interested in the final moments now. One of the possibiliti...
by prasannasimha
10 Sep 2019 23:28
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 2274
Views: 341707

Re: Chandrayan-2 Mission

The small thrusters are 25 N ones From the paper that ramana gave link to: Chandrayaan-2 Lander will employ a clustered configuration of four 800N engines along with 50N attitude control thrusters placed at the bottom of spacecraft, to decelerate the spacecraft for braking and soft landing on lunar...
by prasannasimha
10 Sep 2019 14:24
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 2274
Views: 341707

Re: Chandrayan-2 Mission

^ 6 degrees of freedom. Pitch yaw and roll are the other 3. 3 DOF is only for a point object.
by prasannasimha
10 Sep 2019 13:32
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 2274
Views: 341707

Re: Chandrayan-2 Mission

Image
by prasannasimha
10 Sep 2019 08:46
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 2274
Views: 341707

Re: Chandrayan-2 Mission

The plane sune wavd is the carrier wave. The modulated wave pic is tge data transmission occuring. No terrestrial telescope has the resolution to even image Apollo landing sites and can only be imaged by LRO and now Chandrayaan. This is dictated by optics. Our largest telescope does not have the two...
by prasannasimha
10 Sep 2019 00:23
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 2274
Views: 341707

Re: Chandrayan-2 Mission

UlanBatori wrote:@JayS : Yes, but what happened to all the 100m-hover and the pattern-matching? Pls read the aiaa paper sections I posted above, thanks.

It probably was at too high a velocity to be able to decelerate to hover
by prasannasimha
10 Sep 2019 00:23
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 2274
Views: 341707

Re: Chandrayan-2 Mission

The small thrusters are 25 N ones
by prasannasimha
10 Sep 2019 00:22
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 2274
Views: 341707

Re: Chandrayan-2 Mission

Everything occurred with the somersault that it did.That is the crux to the whole problem. Why it happened for starters is one issue. After it occurred the correction was automatically attempted and probably worked but the time needed to land after full correction to decelerate to final requirements...
by prasannasimha
10 Sep 2019 00:08
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 2274
Views: 341707

Re: Chandrayan-2 Mission

Paper says that CY-1 (not CY-2) was forced to raise orbit from 100km to 200km to reduce heating. Is this radiant heat from lunar day? Wow! I thought it only reached 200C which should cause radiant heating only like an average day in Sriharikota summer, hain? Doesn't the orbiter rotate to distribute...
by prasannasimha
04 Sep 2019 00:38
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 2274
Views: 341707

Re: Chandrayan-2 Mission

There will be a whole host of system checks before Pragyaan can start its roll out. Remember that Vikram is virtually taking a powered descent and will be virtually dropped from a height of 5 meters and crash to the moon to avoid having a rocket plume distorting the landing site. It will be having c...
by prasannasimha
03 Sep 2019 01:16
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 2274
Views: 341707

Re: Chandrayan-2 Mission

There will be no real time transmissions till the Lander actually lands and the rover panel/slide is opened. We will probably be getting telemetry data. DrSivan told about one cause of Beresheets failure - human interference caused issues and muddled up things so they will allow the Lander to do the...
by prasannasimha
02 Sep 2019 18:16
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 2274
Views: 341707

Re: Chandrayan-2 Mission

Excellent! What would be the challenge of detaching the Vikram lander from the main orbiter, vis-a-vis more or less the same operation on the moon impact probe( MIP) onboard Chandrayaan-1? Is it just a question of more bolts to be sheared, or not even that? Vikram must not collide with the Orbiter ...
by prasannasimha
02 Sep 2019 15:20
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 2274
Views: 341707

Re: Chandrayan-2 Mission

Amber G, ISRO is known for what it has achieved. So are the isotopes the only way to get power? I understand the power source has to be light in weight. So I am not wondering why we not have a giant battery pack. Battery has to be recharged and where and how will the recharging happen = from Solar ...
by prasannasimha
02 Sep 2019 15:13
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 2274
Views: 341707

Re: Chandrayan-2 Mission

The radioisotope thermoelectric generator was never designed for CY2. Typical source would be Pu238. Why wasn’t it used I don’t know, perhaps the implantation would change the design and make the GSLV-III payload heavier. Or cost would go up beyond what was sanctioned in the budget. From what I kno...
by prasannasimha
02 Sep 2019 00:05
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 2274
Views: 341707

Re: Chandrayan-2 Mission

After separation why wait for Sep 7th? Is not the orbital position to commence the soft landing not achieved earlier than 7th? My layman's brain thinks the lander carrying the rover would complete more than on revolution in 4 earth days.... I know I am missing something very basic. This has been di...
by prasannasimha
31 Aug 2019 00:36
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 2274
Views: 341707

Re: Chandrayan-2 Mission

S^3 In such planetary travel/orbits 1km off is important no? Perigee/apogee distance and minor variation here is not important. What's important is the orientation (inclination of the orbit) and phase (= timing -- where CY2 is at one particular point in the orbit relative to ground) so that final V...
by prasannasimha
30 Aug 2019 22:51
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 2274
Views: 341707

Re: Chandrayan-2 Mission

ramana wrote:AmberG, Thanks for the explanation .
Its the corkscrew path to get there.
That accounts for the minor 1km variation in orbits achieved.

S^3 In such planetary travel/orbits 1km off is important no?

Not really corkscrew. they are ellipses that are marked in space time to get a corkscrew
by prasannasimha
27 Aug 2019 00:34
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 2274
Views: 341707

Re: Chandrayan-2 Mission

The US Navy has run into problems with touch screens in some of their naval ships and they are now rethinking of going back to push button type. They had a ship collision recently because the jing bang touch screens failed to respond.

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