Good FindKakarat wrote:https://twitter.com/kakarat2001/status/ ... 8346207232
The final seeker image of #MicrosatR sent by kill vehicle of PDV MkII seconds before hit
.At 14:50 he says that this interceptor has the capability to intercept at an altitude of more than 1000 km!!Kakarat wrote:https://twitter.com/ShivAroor/status/11 ... 6323593216
Videohttps://www.pscp.tv/ANI_news/1OwGWkaAWmpGQThe @DRDO_India chief’s briefing on India’s #MissionShakti anti-satellite test is live here:
I have a different take on this, if you note, virtually every US govt. entity has a different stand than NASA.Prem Kumar wrote:Even discounting the racism (which certainly exists), U.S is reacting to a change in the equilibrium. MMS was happy with maintaining the equilibrium a.k.a. self-castration. Modi has disrupted it, be it surgical strikes or ASAT.
U.S is going through its 5 stages of grief before they accept the new normal. They will bat for Rahul because it will mean a return to the old equilibrium.
Initial part of video showing quick reaction divergent thrusters test answers one of Indranil's question.prasannasimha wrote:https://youtu.be/KRs79t6z7fc
Full DRDO video
Thanks. I enjoy your posts too.Indranil wrote:Amber G,
Thank you for writing such great posts every now and then. You asked if there is more interest, you will write more. Let me register my interest. Please keep these coming.
Physics and math are so beautiful if taught properly. It is a pity how science is taught in schools. To this day, most of my friends think Newton “discovered” gravity because an apple fell on his head!!!
Please keep these illuminating posts coming. I absolutely love to read them. For example, there was one line in your posts: All these objects will come back to the point of impact if there was no decay. It is obvious, but only after I read it.
It's sort of irrelevant who is moving slower or faster)- it's the relative speed which matters here.a goalkeeper blocking a football shot into the box, the goalie just ensure the ball hits him.
Thanks. Interesting article.Dileep wrote:Here is a realistic article about debris threat
The energy released by a ASAT missile at, say 10 km/sec, is about 45,000 joules per gram. This is about 10-15 times TNT of the same mass. In other words having a warhead with explosives in ASAT will not matter as much as a regular Brahmos hitting an ordinary target where you need explosives.syam wrote:Sir, our ASAT missile is more like Brahmos without the warhead. Collision is not explosion in most cases. It leaves wreckage, not blast.Amber G. wrote:To add - Any explosive added really does not matter as KE per mass from KE is quite larger than, say compared to TNT or other explosives.
. (In other words, in an ordinary car collision, energy spent is MUCH less than a explosive so the "wreckage" does not look as bad as a "blast" but at ASAT speed the "wreckage" will look about 10,000 times "worse" and as bad as a "blast". Actually, by understanding gravity we can precisely calculate orbits. One does require math though. (I have taught that stuff as my day job so I can speak about this rather confidently). So permit me to put orbit-science 101 here.Coming to the new orbits and stuff. I think we are underestimating gravity here. Orbits are not roads where things travel. It's like you attach a string to an object and throw it out. Once it runs out of the steam it swings back into place. Of course the momentum will be preserved. That's why the object swings to other side.
Our satellite is like that object with gravity itself acting as the string. It 'swings' around earth. That's why we see max speed at perigee. What happened here is, the satellite was hit when it is 'swinging'. It won't create new orbit. It might increase the 'swinging' hight.
Any way that's what I understood by going through space science #101. Please correct me if I am wrong.
May be I am missing something but..arun wrote:
So if satellite was travelling at 7.5 mt.sec and closing speed was 10 mt.sec then ASAT missile was travelling at 2.5 mt.sec.
?
The test parameters were chosen with extreme caution to minimize the hazard of debris after the impact. Although the missile can take out a satellite at 1000 km, the satellite was purposely injected into a circular orbit very close to the outer atmosphere. This decreased the time for reentry of the particles into the atmosphere. It is currently estimated that Microsat-R disintegrated into about 270 chunks, with a cross section of 10 cm2 or above. All of these are predicted to re-enter the earth’s atmosphere in less than 45 days.
This signals another aspect of the test: the KKV most probably impacted the satellite on its way down. Most of the debris from such an impact are boosted to a lower atmosphere interesting orbits. Therefore, this test is akin to Operation Burnt Frost, conducted by the United States to shoot-down a defunct satellite at nearly the same altitude as the Mission Shakti test. That satellite was about 3 times larger than Microsat-R and contained a significantly higher volume of unused fuel. The satellite disintegrated into over 360 pieces most of which entered lower atmosphere-intersecting orbits within a couple of months. However, one of the projectiles was reportedly boosted to a 3000 km orbit and is yet to re-enter the atmosphere. In contrast, the Chinese chose to shoot down a weather satellite at an altitude of 865 km. The result was a large debris field, a significant part of which is still circling the earth, unlikely to decay anytime in the next couple of decades.
Hi Dileep, let me take a stab and few comments:Dileep wrote:Amber Ji, was waiting for you to comment. Would you be able to comment on the following notions I figure?
1. The new perigee of any piece cannot be lower than the impact point (because the object returns there.. DUH!
2. If debris is thrown all around (from an almost circular orbit), most of them will end up with a lower perigee than the current orbit. Only a small percentage will end up with a perigee between the current orbit and the impact point altitude.
3. The HTK kinetic impact is no different from an 'explosion'. It is all energy release.
4. The direction of impact doesn't matter much when both objects disintegrate into pieces much smaller than the original ones.
TIA
It helped big time, amber ji. Thanks for the detailed explanation. I know next to nothing about space science few days back. Kinda slogging it to understand wth going on.Amber G. wrote:Syam - Let me put my perspective, hope it helps.
The energy released by a ASAT missile at, say 10 km/sec, is about 45,000 joules per gram.
In other words, in an ordinary car collision, energy spent is MUCH less than a explosive so the "wreckage" does not look as bad as a "blast" but at ASAT speed the "wreckage" will look about 10,000 times "worse" and as bad as a "blast".
My bad. I was going with basic equation. I first read Newton canon ball, adapted it for my 'swing' example. Guess it missed the target big time. Thanks for the equations, sir.~~ orbit-science #101
I hope this is helpful.
DRDO chief explained it. If something gone wrong, things would have gone wrong in last 10 days. Everything is ok so far. That's enough for me. If nasa is still worried, they should try steering wheel and brakes for their iss to dodge the debris.The math becomes quite complex and one depends on computer simulations and statistical analysis to study orbit decay.
). One can see several corrections to KKV course (evident by the movements of the blue 'lock-on box' in the video) in that 1 second (more than 6-8 course corrections). That video will make our red friends think a bit harder. It was released especially for eleven saab's viewing pleasure.That was the most interesting part I have read in this whole tamasha.ramana wrote:I don't get what the bokwas whine is all about using BMD for ASAT?
Which moron will start from scratch when you have a working BMD system? I am sure US also has done that. The mention of SM-3 and GMD with HTK confirms that.
). Because of the extreme speed of the satellite in orbit (~ 7.5 km/s) the "H2K" (a.k.a. "Smart Rock / Brilliant Pebble") killer vehicle does not have to be going fast w.r.t. the ground: it can be reaching the top of its rise and beginning to come slowly straight down (no one does that, sure) and so traveling at 1 cm per second w.r.t. Earth, as long as it is in the right place at the right instant to be in front of the satellite. So it is very different from the case of, say, an ATGM. Also the target will have a tough time maneuvering "out of the way" in time, and even if it does, it will now be in a very different orbit and face rapid decline - like a car dodging a large pakistani beeing in the middle of a mountain pass road. Meanwhile the killer can move a bit in any direction (not cover much distance) because it is at very low kinetic energy, not much thrust needed to change orbit plane. However, India had only tested targets simulating re-entry vehicles of medium range ballistic missiles, that is targets which were moving at a speed of about 2 km/s. Hence the system had to be upgraded to track targets which were moving much faster, at speeds of around 7 km/s.
...
Based on the above analysis, the following characteristics of the missile emerge. It is a three stage missile with a diameter of 1.4 m and a length of nearly 13.2 m. The first two stages cumulatively weigh around 17.2 tonnes (t) carrying 16.7 t of fuel. The PDV-derived third stage which includes the KKV weighs around 1.8 t, bringing the overall weight of the missile to around 18.5 t (slight error here 17.2 +1.8 = 19.0 tons). Such a missile should be able to take out targets up to an altitude of 1000 km.
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Before the missile is launched, the fire control system estimates an approximate impact point based on the projected flight path of the target and the flight characteristics of the missile. This estimated flight path is uploaded onto the flight computer which is also housed in the third stage of the missile before the launch. After launch, the flight computer guided by a highly accurate ring laser gyroscope based inertial navigational system (RLG-INS) provides control commands to the thrust vectoring systems of the first and second stage to guide the rocket along this pre-calculated path.
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The booster stages separate after burn up. The heat shield also separates once the missile has cleared the atmosphere. Once the kill vehicle is in the vicinity of the impact point, it switches on its Imaging Infrared (IIR) seeker.
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Once the target is locked, the kill vehicle homes onto its target for a hit-to-kill (HTK) interception. The accuracy needed to achieve such a kill is, let us say, non-trivial. The two projectiles approach each other at nearly 10 km/s, whereas the accuracy of the hit is measured in centimeters. To achieve such accuracy, four divert thrusters placed at 90 degrees to each other are used. These thrusters create short and precise rocket pulses to modify the attitude of the KKV or create a translation if needed. In addition to these four main-thrusters, 8 more ports are visible along the base of the third stage. It is unclear whether these ports are part of a longitudinal motor placed at the base of the third stage (the guess has been confirmed. Should give SJha his due credit here).
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The test parameters were chosen with extreme caution to minimize the hazard of debris after the impact. Although the missile can take out a satellite at 1000 km, the satellite was purposely injected into a circular orbit very close to the outer atmosphere. This decreased the time for reentry of the particles into the atmosphere. It is currently estimated that Microsat-R disintegrated into about 270 chunks, with a cross section of 10 cm2 or above. All of these are predicted to re-enter the earth’s atmosphere in less than 45 days.
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It is very unlikely that India will conduct another ASAT test in the near future, especially against a real satellite. There is simply no need: India has already demonstrated its capability which is verifiable by all the majors power in the world. If any further refinements are required, the tests are likely to be against electronic targets, may be at higher orbits.
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The RLG-INS of the PDV Mk-II is the most advanced of any Indian missile designed till date. This is likely to be adapted to long range ballistic missile to increase their accuracy as well.
---Satellite-killer not a one-off, India working on star wars armoury
India is now also working to develop other counterspace capa ..
Read more at:
http://timesofindia.indiatimes.com/arti ... aign=cppst
https://timesofindia.indiatimes.com/ind ... 758674.cms
NEW DELHI: After successfully testing an anti-satellite (ASat) missile last month, India is now also working to develop other counterspace capabilities like directed energy weapons (DEWs) and co-orbital killers as well as the ability to protect its own satellites from electronic or physical attacks.
“We are working on a number of technologies like DEWs, lasers, electromagnetic pulse (EMP) and co-orbital weapons etc. I can’t divulge the details, but we are taking them forward,” said DRDO chief G Satheesh Reddy on Saturday. The A-Sat missile that destroyed the Microsat-R satellite, at an altitude of 283-km in the low-earth orbit (LEO) on March 27, was a “directascent, kinetic kill” weapon. It’s “feasible” to target multiple satellites with multiple launches of the three-stage interceptor missile, which can go up to 1,000 km into space," said the DRDO chief.
A coorbital weapon, in turn, is basically a satellite equipped with some explosive, weapon or DEW device, which is first put into orbit and then later manoeuvred to target the enemy satellite. Apart from these kinetic kill weapons, other ASAT weapons like lasers jammers, EMP and high-powered microwaves are being rapidly developed by China, which first tested an A-Sat missile against a LEO weather satellite in January 2007.
Trying to play catch-up, sources say India’s long-term aim is to develop A-Sat weapons against satellites in both LEO and GEO-synchronous orbits as a credible deterrence against emerging threats to its growing spacebased assets. “Conversely, EMP hardening of our satellites and sensors, apart from other measures, can be done to protect them from our adversaries,” said a source.
"There is a plan to launch mini-satellites on demand for the armed forces if the main satellites are targeted,” said a source. DRDO for long has also been running programmes on a wide variety of DEWs like high-energy lasers and highpowered microwaves capable of destroying aerial and ground-based targets, but whether they can be successfully developed into A-Sat weapons remains to be seen.
DRDO chief G Satheesh Reddy, on his part, said it was for the government to decide on the issue of weaponisation of A-Sat systems or the creation of a fullfledged Aerospace Military Command. “Space has gained importance in the military domain. The best way to ensure security is to have deterrence,” he said. The DRDO chief made it clear that there was no move to conduct additional tests of the new A-Sat missile as of now.
“Though we tested the interceptor missile for an altitude below 300 km as a responsible nation after multiple simulations, it has the technical capability to go beyond 1,000 km. That will cover most of the orbiting satellites in LEO. For the same purpose, we don’t need more tests,” he said. The target satellite was hit with an accuracy of less than 10 cm, on par with “the best reported performances” of such A-Sat missiles worldwide. “So, it meets all our objectives. The successful demonstration of ‘Mission Shakti’ has placed India in the elite club of three countries (US, Russia and China) possessing the A-Sat capability,” Reddy added.
1.You are right, my bad, Km Sec it is.Amber G. wrote:May be I am missing something but..arun wrote:
So if satellite was travelling at 7.5 mt.sec and closing speed was 10 mt.sec then ASAT missile was travelling at 2.5 mt.sec.
?
1 - The speeds are of the order of 10 Km/sec .. not mt.sec..
2 - The velocities are vectors, so one can not just "add" or "subtract" scaler values. (Of course, one does not have to guess, all the speeds are accurately known)
If any missing something is happening, it is more likely from my end ........SaiK wrote:loads of pics here
https://twitter.com/strategic_front/sta ... 9264355328
..........{Rest Snipped}..........
AFAIK, the Indian ASAT test worked perfect, first time. Nagararajamani Khan BuddharakhitaTero Appukkuttan Makal Parukutti Singh Gangopahdyay probably got 100/100 in SSLC math so she made no mistake in her calculations and had the trajectories calculated down to 2 millimeters Circular Error Probability,When the Paki sees the KI approaching, and death is certain, it triggers a soosai vest and blows itself up. This was how the Sergeant York anti-aircraft gun was tested in demonstration. They used a helicopter to test it (moves slower than an airplane..). Then they got the helicopter to hover. Then they made damn sure by putting an explosive charge on the helicopter, and triggering it a second after the gun "fired". Very spectacular, the Mantris/ Netas went back to COTUS and voted a few $B for the budget to make this.
