Search found 1046 matches

by SriKumar
28 Sep 2018 07:28
Forum: Technology & Economic Forum
Topic: Civil Aviation Development & Discussion
Replies: 5543
Views: 475365

Re: Civil Aviation Development & Discussion

I wonder why they didn't declare an emergency. I've been binge-listening to ATC recordings and transcriptions here - https://www.youtube.com/user/victor981994/videos - noticed that less serious issues got the pilots to declare an emergency (I guess to get priority on airspace movements and landing)...
by SriKumar
27 Sep 2018 08:30
Forum: Military Issues & History Forum
Topic: Mangalyaan : ISRO's Mars Orbiter Mission
Replies: 2751
Views: 118149

Re: Mangalyaan : ISRO's Mars Orbiter Mission

At that time (and placement of Mars relative to earth in 2013) the time for one-way travel of signal was 8 minutes- quoting from memory here. There are some technically incorrect things...one guy talks about escape velocity. The craft did not reach escape velocity (it does not need to). Then he says...
by SriKumar
25 Sep 2018 07:37
Forum: Military Issues & History Forum
Topic: Indian Space Program: News & Discussion - Sept 2016
Replies: 3932
Views: 806822

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

Sure. Will read what you write, Amber.G.
One thing that's interesting is that the linear velocity of earth's surface will keep changing as the satellite traverses north to south and back....so if the satellite wants to stick to one particular longitude it will have to constantly correct for it.
by SriKumar
22 Sep 2018 16:54
Forum: Military Issues & History Forum
Topic: Indian Space Program: News & Discussion - Sept 2016
Replies: 3932
Views: 806822

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

^^^ Why would the location make a difference to the payload? As far as I can see, the launches from Guj. or TN would be in a polar orbit, since there is land on the eastern side (for both locations). For polar orbits, I dont think proximity to equator matters, does it? Earth's rotational push is use...
by SriKumar
19 Sep 2018 07:30
Forum: Military Issues & History Forum
Topic: Indian Space Program: News & Discussion - Sept 2016
Replies: 3932
Views: 806822

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

Agree with the need to shut up T-5 min to satellite ejection. They can talk technical details prior to T-10 or T-5 min. If there's any way to get the word out to ISRO on this point I would like to petition them......I prefer to hear 'parfaarmans naarmal' to the 'vimaan ka pratham charan ab prajwalit...
by SriKumar
15 Sep 2018 19:59
Forum: Military Issues & History Forum
Topic: Indian Space Program: News & Discussion - Sept 2016
Replies: 3932
Views: 806822

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

More details of SSLV. Credit to pgoi (on redditt) . Interesting that the fins control roll. So, are they active? I assume they are active, not sure though. The last-but-one slide talks about roll control for 2nd and 3rd stages, yet there are no fins on these stages. So what's controlling the roll t...
by SriKumar
15 Sep 2018 19:43
Forum: Military Issues & History Forum
Topic: Indian Space Program: News & Discussion - Sept 2016
Replies: 3932
Views: 806822

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

Very informative set of slides, Indranil. Thanks for posting.
Materials, construction, dimensions, propellant quantity, thrust are all provided (even schedule).
by SriKumar
02 Sep 2018 19:56
Forum: Technology & Economic Forum
Topic: Physics Discussion Thread
Replies: 2513
Views: 94462

Re: Physics Discussion Thread

Is it possible to calibrate a more precise instrument (e.g.a LIGO) with a less precise instrument (e.g. vibration/seismic detectors). If you are aware of any specific literature on this process for LIGO, I am interested. The Caltech MIT link said that active control of the pendulum system is monitor...
by SriKumar
02 Sep 2018 19:19
Forum: Technology & Economic Forum
Topic: Physics Discussion Thread
Replies: 2513
Views: 94462

Re: Physics Discussion Thread

Thanks for the clarifications. I was just trying to understand the time-varying aspect of the fringe pattern. The LIGO should be oscillating back and forth due to the gravitational wave, and this changes the fringe pattern as a function of time. Fringes are a essentially a spatial variation of light...
by SriKumar
01 Sep 2018 08:10
Forum: Technology & Economic Forum
Topic: Physics Discussion Thread
Replies: 2513
Views: 94462

Re: Physics Discussion Thread

Another link which is good is from Caltech's lecture.. https://labcit.ligo.caltech.edu/~ajw/LIGO_SURF02_4.pdf Very interesting presentation. Wish I had known more physics (topics) to understand some of the slides. I see they used active seismic isolation. What was used as an (absolute) frame of ref...
by SriKumar
31 Aug 2018 16:48
Forum: Technology & Economic Forum
Topic: Physics Discussion Thread
Replies: 2513
Views: 94462

Re: Physics Discussion Thread

.And so far I have not read any link as I don't yet have time. Well, I see you had time to read my posts, make posts here (and on other threads too) :D so, let me offer a few lines from the link I posted. The note below is more informative than any of my posts so far. https://www.ligo.caltech.edu/p...
by SriKumar
31 Aug 2018 16:43
Forum: Technology & Economic Forum
Topic: Physics Discussion Thread
Replies: 2513
Views: 94462

Re: Physics Discussion Thread

Note that it has been mentioned above as a 'separate issue', after implying earlier how two LIGOs somehow solve the problem of isolating vibrations in any one LIGO). . Note your original question. You were talking about differentiating earth quakes from ligo events, not systemic instumental error. ...
by SriKumar
31 Aug 2018 09:56
Forum: Technology & Economic Forum
Topic: Physics Discussion Thread
Replies: 2513
Views: 94462

Re: Physics Discussion Thread

In other words, if the accuracy of one (or both) instruments is suspect, then we dont know what is being recorded. That's what I said right here : The effect of other vibrations masking a ligo event however is a separate issue. Essentially the signal to noise ratio has to be maximized through vario...
by SriKumar
30 Aug 2018 17:39
Forum: Technology & Economic Forum
Topic: Physics Discussion Thread
Replies: 2513
Views: 94462

Re: Physics Discussion Thread

A second (or third) LIGO is not going to help if each LIGO is not isolated well from even faint vibrations. Each LIGO instrument has to be absolutely isolated from any vibration given that they are so super-sensitive. An earthquake or other seismic events are going to affect each LIGO differently ....
by SriKumar
30 Aug 2018 04:48
Forum: Technology & Economic Forum
Topic: Physics Discussion Thread
Replies: 2513
Views: 94462

Re: Physics Discussion Thread

How are they able to isolate the LIGO from earth's vibrations (I know there's a 10 mile buffer zone or something like that) but at that level of precision, vibrations from earthquakes anywhere on earth and minor plate tectonic movements could affect its functioning? They have 2 ligos spread out geo...
by SriKumar
28 Aug 2018 04:30
Forum: Technology & Economic Forum
Topic: Physics Discussion Thread
Replies: 2513
Views: 94462

Re: Physics Discussion Thread

For LIGO, the precision is about BILLION (Yes, a billion) times more ! This is almost unbelievable. IOW i f you take the distance between earth and Alpha Century (4+ light years).. it measures/detects the variation of the order of thickness of a hair. = Just think about that. How are they able to i...
by SriKumar
13 Aug 2018 02:48
Forum: Military Issues & History Forum
Topic: Indian Space Program: News & Discussion - Sept 2016
Replies: 3932
Views: 806822

Re: Indian Space Programme Discussion - Sept 2016

Good find Kurup. Some good information. Prasannasimha's one-line post mentioned Chellikere by name and I saw that it was in the middle of Karnataka and was wondering how the hell would ISRO launch from Sriharikota and land in Karnataka with all the population centres in between. And a 3 km drop did ...
by SriKumar
12 Aug 2018 00:28
Forum: Military Issues & History Forum
Topic: Indian Space Program: News & Discussion - Sept 2016
Replies: 3932
Views: 806822

Re: Indian Space Programme Discussion - Sept 2016

^^^ Any idea if it will be landed on land (and not water like the previous RLV)? On a runway? Which one- the previous RLV needed a runway longer than any that had existed then. If landing on a runway, one assumes the other side of the craft in the picture will show landing gear. One assumes this one...
by SriKumar
11 Aug 2018 06:37
Forum: Military Issues & History Forum
Topic: Indian Space Program: News & Discussion - Sept 2016
Replies: 3932
Views: 806822

Re: Indian Space Programme Discussion - Sept 2016

Super high-res here https://i.pinimg.com/originals/d8/f1/c8/d8f1c8f66d0f9cf0291e63663d2151aa.jpg I can see space for 6 strapons solid or liquid. Why you say there is no space? I'd say there is almost or literally no space for 4 strap-ons of the type shown in the figure (unless it is in a rotated co...
by SriKumar
09 Aug 2018 08:08
Forum: Military Issues & History Forum
Topic: Indian Space Program: News & Discussion - Sept 2016
Replies: 3932
Views: 806822

Re: Indian Space Programme Discussion - Sept 2016

^^^Admiral, Sriharikota is an island (of sorts) sitting in A.P. and not T.N. .....unless this is a chankian move to further confuse our friends who are seriously searching for Bangalore, Kerala. :D Feel free to delete this post once the correction is in place.
by SriKumar
06 Aug 2018 06:03
Forum: Mil-Tech Archive
Topic: Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018
Replies: 3910
Views: 885103

Re: Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018

Gyan, The requirements are a mix of musts and wants with sundry sources giving these out. The musts not yet accomplished are: Gun firing in air Air to air refueling Self jamming pod Wants are: Software defined radio This could end up with avionics impact. HAL has two lines 5+3 aircraft division. An...
by SriKumar
05 Aug 2018 04:24
Forum: Military Issues & History Forum
Topic: Indian Space Program: News & Discussion - Sept 2016
Replies: 3932
Views: 806822

Re: Indian Space Programme Discussion - Sept 2016

It should be noted that from the early 1980s the various candidate configurations for GSLV indicated a strong need for modular solid strap-on. Till 1984 no substantial progress was made in the design of the PSLV launch pad. An opportunity was available to build the facility which would cater to the...
by SriKumar
29 Jul 2018 18:50
Forum: Military Issues & History Forum
Topic: Indian Space Program: News & Discussion - Sept 2016
Replies: 3932
Views: 806822

Re: Indian Space Programme Discussion - Sept 2016

You need to do a trade study for all up configurations and get the best option. For example, the final (slightly suboptimal) GSLV configuration was governed by the launch site design! Design or location? If design, that's funny/interesting. I am assuming it has to do with either the strength of the...
by SriKumar
24 Jun 2018 07:54
Forum: Mil-Tech Archive
Topic: Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018
Replies: 3910
Views: 885103

Re: Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018

Well Dilip, my posts mentions most of what you mention.....wake, validation, programming AND testing explicitly. I dont know of what specific problem was reported here, feel free to mention it again. I could think of one other scenario e.g. refueling in 'less than perfect' turbulent weather (= weath...
by SriKumar
24 Jun 2018 06:27
Forum: Mil-Tech Archive
Topic: Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018
Replies: 3910
Views: 885103

Re: Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018

Automatically adapting to weight and center of gravity changes during flight should already be part of the flight control should it not? Surely the fuel load changes all the time during flight as the aircraft burns fuel or has to dump it's fuel for an emergency landing. Ditto for following in the w...
by SriKumar
23 Jun 2018 21:06
Forum: Mil-Tech Archive
Topic: Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018
Replies: 3910
Views: 885103

Re: Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018

Indranil wrote:They are not worried about the fuel transfer, but the ability to fly in the wake for long durations.
One assumes flight control laws have to be modified and tested as well to account for changing center of gravity during in flight refueling (in the presence of a wake).
by SriKumar
22 Apr 2018 18:21
Forum: Military Issues & History Forum
Topic: Indian Air Force News & Discussion - 15 Dec 2016
Replies: 3156
Views: 665464

Re: Indian Air Force News & Discussion - 15 Dec 2016

Just wondering if Gaganshakti involved deployments, movements or actual firing of Brahmos (individual or salvos). Am assuming it must have been, it is after all Gagan Shakti.....and so anything air-breathing and within limits of gagan would fit. What about A5 and A4 mobile units..... if not done in ...
by SriKumar
15 Apr 2018 03:08
Forum: Military Issues & History Forum
Topic: Indian Space Program: News & Discussion - Sept 2016
Replies: 3932
Views: 806822

Re: Indian Space Programme Discussion - Sept 2016

If this thing does not get sorted out in an year or so, perhaps one could consider launching a 'relay communication' satellite with a GSLV launch (in addition to the scheduled payload). This 'relay comm' satellite should be brought to the same orbit and in proximity to the disabled satellite to esta...
by SriKumar
12 Apr 2018 14:32
Forum: Military Issues & History Forum
Topic: Indian Space Program: News & Discussion - Sept 2016
Replies: 3932
Views: 806822

Re: Indian Space Programme Discussion - Sept 2016

If ISRO can pull it off and I hope they do, it will be nothing short of miraculous. This is the normal strategy of management to give hope to stakeholder, till the incident fades away from memory. I dont know if the implication is that ISRO is trying to mislead public or give false hope. Who is the...
by SriKumar
13 Mar 2018 05:35
Forum: Technology & Economic Forum
Topic: Know Your India
Replies: 513
Views: 58659

Re: Know Your India

We also have snow leopards and clouded leopards. Less than a century ago, we also had Cheetahs. The last three were hunted in 1948, by a royal no less. Pen pineapple apple pen! So there!! :twisted: So we know India had cheetahs until very recently. How many know that they were paaltu and used by ro...
by SriKumar
12 Feb 2018 07:33
Forum: Mil-Tech Archive
Topic: Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018
Replies: 3910
Views: 885103

Re: Tejas: News & Discussions: 09 February 2018

THanks srai. Somehow, googling around did not get me the link. (The link should be a sticky.). I was curious about the flight hours for any one airframe. LSP5 (379) has done almost as many flights as PV3 (387). About 250-260 hours of flight time (at 40 min per sortie). This is good that the LSPs are...
by SriKumar
11 Feb 2018 23:17
Forum: Mil-Tech Archive
Topic: Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018
Replies: 3910
Views: 885103

Re: Tejas: News & Discussions: 09 February 2018

Guys, Where is that website where the number of flight hours accumulated on each craft used to be posted?
Or was it some poster on this thread who used to compile it? Even number of flights is good enough (each flight used to take about 40 minutes).
by SriKumar
11 Feb 2018 23:16
Forum: Mil-Tech Archive
Topic: Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018
Replies: 3910
Views: 885103

Re: Tejas: News & Discussions: 09 February 2018

I think now we can only fail at three things - 1) HAL dropping the ball on delivering LCA MK 1 of high quality in time (I am bothered by HAL insisting that most of it has been passed to private party and if they delay, then it's their problem, not HAL) rgds I dont know much about HAL but I think in...
by SriKumar
11 Feb 2018 06:54
Forum: Mil-Tech Archive
Topic: Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018
Replies: 3910
Views: 885103

Re: Tejas: News & Discussions: 09 February 2018

In the early stages of LCA flights, I had read that every 2 months the entire aircraft would be dis-mantled, checked for issues and then 're-mantled' and flown again. This was done over and over. Is it still being done for any of PVs and the LSPs that are flying now? A related question: what is the ...
by SriKumar
10 Feb 2018 23:41
Forum: Mil-Tech Archive
Topic: Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018
Replies: 3910
Views: 885103

Re: Tejas: News & Discussions: 09 February 2018

This clarification by ramana deseves to be carried over. Cleared up a lot of confusion about how many Tejas lines, capacity , and thier operational status. The original line is 5/year. Tejas Division. Confirmed Then comes half line in the Hawk hangar at 3/year. Aircraft Division. Confirmed SP5 from ...
by SriKumar
10 Feb 2018 22:43
Forum: Military Issues & History Forum
Topic: International Aerospace Discussion - Jan 2018
Replies: 1152
Views: 189812

Re: International Aerospace Discussion - Jan 2018

Freshers? lol. How about interns? Vets? Which vets? Found this on teh web, from 2012 (when the consultancy I once worked for *tried* to got involved with them): What caught our eye, though, was SpaceX founder Elon Musk’s musings about how he hopes to staff up his company going forward. Noting that ...
by SriKumar
10 Feb 2018 07:19
Forum: Military Issues & History Forum
Topic: International Aerospace Discussion - Jan 2018
Replies: 1152
Views: 189812

Re: International Aerospace Discussion - Jan 2018

Quite the video. One sees the (Rapid) depolyment of the massive landing legs just 10 seconds before landing. The rocket engine relights are seen at 8:15 and the sonic booms heard around 8:45. AT 333 m/s speed of sound at sea level, that places the camera nearly 10 kms away. The rapidity of deploymen...
by SriKumar
09 Feb 2018 06:07
Forum: Military Issues & History Forum
Topic: International Aerospace Discussion - Jan 2018
Replies: 1152
Views: 189812

Re: International Aerospace Discussion - Jan 2018

Several interesting things about this launch: 1. The solid rockets smoke only during ignition. After lift-off, no smoke. No smoke trail. 1.1 There was white smoke, and then black smoke on the launch pad, perhaps two different solid fuels are being used. 2. The rockets that landed back .....it seems ...
by SriKumar
27 Jan 2018 20:05
Forum: Military Issues & History Forum
Topic: India's R&D in Defence DRDO, PSUs and Private Sector
Replies: 3678
Views: 479595

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

I don't understand why you guys find it humorous! Most native speakers would find it beyond funny. And I am a guy who actually enjoys DD brand sanskritized hindi.. The document is in such klisht/high falutin hindi as to be nearly incomprehensible. Dont want to prolong the OT but yes, I agree. I nev...

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