Search found 105 matches

by RonyKJ
14 Sep 2019 23:57
Forum: Mil-Tech Archive
Topic: Naval Tejas Mk1/Mk2: News & Discussion - 23 February 2019
Replies: 688
Views: 156921

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

Is there a way for the pilot to see the location of the cable and the arrestor hook while landing?
Or does he go by markings on the deck?
by RonyKJ
05 Sep 2019 05:52
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 2219
Views: 283236

Re: Chandrayan-2 Mission

It depends on the deformation distance assumed. We need to know how much the shocks on the legs move or how much the legs dig into the ground. Energy of an object weighing 1471 kg falling from hover at 1.622 m/s2 over a distance of 2 meters is given by: E = mgh = 1471 x 1.622 x 2 kgm2/s2 (Joules) = ...
by RonyKJ
04 Sep 2019 22:22
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 2219
Views: 283236

Re: Chandrayan-2 Mission

The simple answer to why there is no RTG heater on Pragyan is that we haven't yet developed an RTG heater.
by RonyKJ
02 Sep 2019 21:23
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 2219
Views: 283236

Re: Chandrayan-2 Mission

I didn't understand the flipping here. Can you please explain Dr Sivan in his press conference https://youtu.be/njzOans5P-c mentioned that on Sep 3, Vikram will be rotated 180 degree and there will be a small burn. Then it will be rotated back. Then again on Sep 4, it will be rotated again 180 degr...
by RonyKJ
02 Sep 2019 20:00
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 2219
Views: 283236

Re: Chandrayan-2 Mission

If I understand correctly, Vikram has to be flipped around 180 degrees before firing its engines to deorbit. Then it has to be flipped back again for the landing.
by RonyKJ
01 Sep 2019 06:55
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 2219
Views: 283236

Re: Chandrayan-2 Mission

Forgot to mention that the bolt cutting method is also almost instantaneous, which is also a requirement considering the
precision required to achieve the pinpoint landing at a specific time.
by RonyKJ
01 Sep 2019 06:52
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 2219
Views: 283236

Re: Chandrayan-2 Mission

There are many other ways to separate two attached objects but none are as simple and reliable as cutting a bolt. The bolt cutting method not only severs the connection but also provides a push in the same action due to the fact that the holding clamps are springs. All that is needed is to turn a sw...
by RonyKJ
23 Aug 2019 23:13
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 2219
Views: 283236

Re: Chandrayan-2 Mission

I really hope that ISRO has got high definition cameras in the lander/rover. Does anyone know the specs of these cameras, their resolution? If it is DD like coverage/resolution of their launches, it will be a disaster. I know data transfer rates are the bottleneck for transmitting high resolution p...
by RonyKJ
23 Aug 2019 23:00
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 2219
Views: 283236

Re: Chandrayan-2 Mission

I think the issue of determining velocity and position may not be as complicated. The orbiter can send out signals with a time stamp which can be received by the IDSN. The time lag between transmission and receipt of signal can be used to calculate distance to orbiter Subsequent signals can be simil...
by RonyKJ
20 Aug 2019 19:28
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 2219
Views: 283236

Re: Chandrayan-2 Mission

There were a couple of occasions when Dr Sivan was asked about how the landing date was maintained even though the launch date slipped by a week. It was my understanding that this would be done by reducing the number of orbits around the moon after LOI was achieved. But Dr Sivan did not mention that...
by RonyKJ
29 Jul 2019 23:56
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 2219
Views: 283236

Re: Chandrayan-2 Mission

10km circular orbit around moon would not be sustainable for long due to the variation in moon's gravity. The orbit would soon become distorted and huge amounts of fuel would be needed to correct it. This was attempted during Apollo 15/16 by releasing a sub-satellite called PFS1 and PFS2 https://sci...
by RonyKJ
22 Jul 2019 17:43
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 2219
Views: 283236

Re: Chandrayan-2 Mission

The plot is a bit confusing. Horizontal axis is time in seconds. White vertical axis shows rel velocity. What is the red vertical axis? Is it altitude? But it doesn't correspond to the read out. At 944.5 secs, read out says altitude is 171.4 km but graph corresponds to 550. It would seem like under ...
by RonyKJ
22 Jul 2019 15:29
Forum: Military Issues & History Forum
Topic: Chandrayan-2 Mission
Replies: 2219
Views: 283236

Re: Chandrayan-2 Mission

Successful launch and insertion of spacecraft. Dr Sivan mentioned that there was an over performance leading to a bonus of 6000 km which means that the satellite team have excess fuel available for manouvers.
by RonyKJ
08 Apr 2019 19:37
Forum: Military Issues & History Forum
Topic: Tejas Mk.1 & Mk.1A: News & Discussions: 23 February 2019
Replies: 2004
Views: 575428

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

Today I watched Dr Anantha Krishnan,s interview with Dr Kota. he undoubtedly is one of mother India,s great sons. it made me very sad that one year after this interview there are a measly 2ooo odd people who watched it. While a third rate bollywood song gets 500 million hits while the man who helpe...
by RonyKJ
01 Apr 2019 09:59
Forum: Military Issues & History Forum
Topic: Indian Space Program: News & Discussion - Sept 2016
Replies: 4200
Views: 930232

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

40 min later restart of PS4 for launch of 29 sats
by RonyKJ
01 Apr 2019 00:39
Forum: Military Issues & History Forum
Topic: Indian Space Program: News & Discussion - Sept 2016
Replies: 4200
Views: 930232

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

I had been hoping and suggesting to ISRO officials over 10 years ago to develop the infrastructure for tourists at Sriharikota. I am glad this is happening.
It would be great to have a civilian airport as well near Sullurpeta.
by RonyKJ
01 Apr 2018 00:33
Forum: Technology & Economic Forum
Topic: Google Lunar XPRIZE and Space 2.0 Discussion
Replies: 241
Views: 40121

Re: Google Lunar XPRIZE and Space 2.0 Discussion

Although the X-prize has ended, many of the teams are still continuing the pursuit. Team Indus has canceled its contract with ISRO and is looking for a new launch company. This is a big disappointment. I don't know if we will ever find out the real reasons for the cancelation but I am inclined to th...
by RonyKJ
09 Jan 2018 23:00
Forum: Military Issues & History Forum
Topic: Indian Space Program: News & Discussion - Sept 2016
Replies: 4200
Views: 930232

Re: Indian Space Programme Discussion - Sept 2016

Very disappointed to hear this. I think Team Indus did a terrible job of fund raising. At one time they had announced that they would be doing a round of public funding. I contacted them on their website expressing interest in being an investor but received no response. They had people dedicated to ...
by RonyKJ
30 Dec 2017 03:16
Forum: Technology & Economic Forum
Topic: Google Lunar XPRIZE and Space 2.0 Discussion
Replies: 241
Views: 40121

Re: Google Lunar XPRIZE and Space 2.0 Discussion

Hakuto is confident about winning https://www.forbes.com/sites/saadiampekkanen/2017/12/19/meet-the-japanese-space-entrepreneur-whos-sure-hell-win-the-google-lunar-x-prize/#b86852c7754e In one of the videos I watched, it mentioned that after the lander lands on the moon's surface, they plan to wait 4...
by RonyKJ
30 Dec 2017 03:03
Forum: Technology & Economic Forum
Topic: Google Lunar XPRIZE and Space 2.0 Discussion
Replies: 241
Views: 40121

Re: Google Lunar XPRIZE and Space 2.0 Discussion

Looks like Team Hakuto has secured all the funding it needs. https://www.techinasia.com/japan-google-lunar-xprize-finalist-gets-90m-funding-for-moon-mission SpaceIL desperate for funds http://spacenews.com/spaceil-making-final-fundraising-push-for-lunar-lander-mission/ Team Indus will start crowd fu...
by RonyKJ
13 Jun 2017 22:45
Forum: Trash Can Archive
Topic: GSLV-Mk III launch program/post-launch analysis
Replies: 424
Views: 65258

Re: GSLV-Mk III launch program/post-launch analysis

I agree. It seemed ridiculous to me that we couldn't refine kerosene to the level required or not be able to modify or create new test facilities to test the semi-cryo engine after we had mastered handling liquid hydrogen.
by RonyKJ
06 Jun 2017 19:17
Forum: Trash Can Archive
Topic: GSLV-Mk III launch program/post-launch analysis
Replies: 424
Views: 65258

Re: GSLV-Mk III launch program/post-launch analysis

I wonder whether ISRO thought about doing an experiment with restarting the cryo stage in space after its job was done. We do need to develop restart capability for the future.
by RonyKJ
12 May 2017 06:17
Forum: Military Issues & History Forum
Topic: Indian Space Program: News & Discussion - Sept 2016
Replies: 4200
Views: 930232

Re: Indian Space Programme Discussion - Sept 2016

I agree with you Jagan. As an outward looking nation seeking to become a global power and engage the world, we need to look inward and project a more polished, marketable image of ourselves and our capabilities. Every single detail, from the camera work to the countdown counts towards creating this ...
by RonyKJ
04 May 2017 08:18
Forum: Military Issues & History Forum
Topic: Indian Space Program: News & Discussion - Sept 2016
Replies: 4200
Views: 930232

Re: Indian Space Programme Discussion - Sept 2016

What is the advantage of liquid engine in 3rd stage vs a solid motor? Does lack of O2 up there means only liquid is possible? How then do icbm use solid motor in 3rd stage? If you are referring to GSLV Mark 2, the third stage is the 7.5 ton cryo engine which uses liquid oxygen and liquid hydrogen. ...
by RonyKJ
03 May 2017 21:50
Forum: Military Issues & History Forum
Topic: Indian Space Program: News & Discussion - Sept 2016
Replies: 4200
Views: 930232

Re: Indian Space Programme Discussion - Sept 2016

There is an advantage in specific impulse, but more in vacuum than sea level,
so the penalty of using it in lower stages is not as much.
LOX-Kerosene Isp is 300 at sea level and 353 in vacuum
UDMH-N2O4 Isp is 285 at sea level and 333 in vacuum
by RonyKJ
16 Apr 2017 02:43
Forum: Military Issues & History Forum
Topic: Indian Space Program: News & Discussion - Sept 2016
Replies: 4200
Views: 930232

Re: Indian Space Programme Discussion - Sept 2016

It is high time that either ISRO or the state builds an airport at Sullurpeta, the small town near SHAR. It would save a lot of time in transporting satellite payloads from Bangalore. I would think that a convoy travelling at 10mph is going to create congestion on the roadways during its 34 hour tri...
by RonyKJ
01 Jun 2016 07:02
Forum: Trash Can Archive
Topic: Indian Space Programme Discussion
Replies: 3934
Views: 270244

Re: Indian Space Programme Discussion

Is there any room for improving upon the PSLV design to increase payload? PSLV started out with design payload of 1 ton. First launch was only about 600 kg and it kept on increasing once confidence was gained. Components that were over designed were trimmed to lower factors of safety. Propellant lo...
by RonyKJ
29 May 2016 20:28
Forum: Trash Can Archive
Topic: Indian Space Programme Discussion
Replies: 3934
Views: 270244

Re: Indian Space Programme Discussion

RLV-TD is becoming X-37B equivalent! Not so fast! RLV-TD is still sub-orbital while X-37B is orbital. The task of returning to land on a runway from orbit will be a lot more challenging, but agreed that this is very exciting. In my opinion the RLV-TD should continue as its own programme toward beco...
by RonyKJ
24 May 2016 03:02
Forum: Trash Can Archive
Topic: Indian Space Programme Discussion
Replies: 3934
Views: 270244

Re: Indian Space Programme Discussion

Read in a news report on Dawn, from AFP, quoting Dr Sivan as saying that they have located the spot
at which the RLV-TD is floating on the sea and that it had a soft landing and did not break
into pieces.
Wonder if this is true and if so, why none of the Indian news media didn't report it.
by RonyKJ
23 Feb 2016 22:37
Forum: Trash Can Archive
Topic: LCA Tejas: News and Discussions
Replies: 4036
Views: 329308

Re: LCA Tejas: News and Discussions

[quote="shiv"] Team HAL upbeat over Tejas’ stupendous success in Bahrain 'Mathrubhumi' visited HAL’s state-of-the-art LCA Tejas Division recently for an interaction with the successful Bahrain team # Dr Anantha Krishnan M http://english.mathrubhumi.com/polopoly_fs/1.884448.1456225792!/imag...
by RonyKJ
27 Aug 2015 21:20
Forum: Trash Can Archive
Topic: Indian Space Programme Discussion
Replies: 3934
Views: 270244

Re: Indian Space Programme Discussion

ISRO needs to develop satellites which can be refuelled.
Then we can use the proven PSLV or even a resuable vehicle
to go refuel the sats. For this we need to develop docking technology
which will be needed anyway for manned flights, space station and so on.
by RonyKJ
02 Aug 2015 20:46
Forum: Trash Can Archive
Topic: Abdul Kalam passes away Oct 15, 1931 - July 27, 2015
Replies: 222
Views: 12624

Re: Abdul Kalam passes away Oct 15, 1931 - July 27, 2015

If anyone is interested in planting trees in honor of Dr APJ Abdul Kalam please visit https://www.grow-trees.com/grove/dr-apj-abdul-kalam-memorial Thank you Kakarat for posting this link. It is a great idea. I have started a corporate account on behalf of my company Zojila to plant trees as carbon ...
by RonyKJ
23 Nov 2014 00:28
Forum: Trash Can Archive
Topic: Indian Space Programme Discussion
Replies: 3934
Views: 270244

Re: Indian Space Programme Discussion

I am Indian and can manage seven languages including Spanish, French and Chinese but I post here only in English because that is the language used by 99.99 percent of the users of the forum. Since this is apparent to anyone visiting this forum, a person posting in a language other than English is th...
by RonyKJ
22 Nov 2014 19:30
Forum: Trash Can Archive
Topic: Indian Space Programme Discussion
Replies: 3934
Views: 270244

Re: Indian Space Programme Discussion

Admins: I think the above post in Hindi should not be allowed unless accompanied by an English translation.
If everyone started posting in regional languages, there would be no more discussion possible on this forum.
by RonyKJ
15 Nov 2014 17:43
Forum: Military Issues & History Forum
Topic: Mangalyaan : ISRO's Mars Orbiter Mission
Replies: 2752
Views: 140673

Re: Mangalyaan : ISRO's Mars Orbiter Mission

Recently the red rain in Kerala has attrated a lot of attention and research and Wickramsingha was there to look
at studies conducted by a local researcher.

Btw, does water have to be delivered by another body? Couldn't it form by itself on a plnaet given the existence
of its constituent elements?

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