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mokoman

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looks like rustom wing tip.

i guess rustom is flying over area , live feed is from it
Not likely ,it seems to me something like animation .

But whoa where are these images from @fire starter
looks to me like image taken from underneath a UAV , its the portion of wing . opened in paint.

looks like other screens are playing video files in windows media player .
 

Okabe Rintarou

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Anyone upto the task ? ( As long as it makes sense )
They are different. Two reasons:-
  • Trajectory
  • Materials
First consider the following image. In it each trajectory is at a different altitude:-
Red trajectory peaks at 1000 km altitude or thereabouts (varies widely per range of missile).
Green trajectory (glide phase) is below 100 km altitude (Karman line).
Yellow is less than 1 km above ground.



A1P has a MaRV, not a boost-glide vehicle. Look at the purple part of the trajectory, that is what A1P RV can do. Green is what the American C-HGB does. But your question is WHY THE HECK WHEN THEY LOOK SO SIMILAR!? And I could go on about the percieved size in difference of fins as well as their slant, but forget that. Here comes the second reason: materials.

Hypersonic flight temperatures through atmosphere can lead to air/spacecraft temperature reaching around 2000 degrees C or more.

In the case of most atmospheric re-entries (terminal part of red/purple trajectories), be it of Spacecraft, Crew capsules, Nuclear RVs or MaRVs, the duration of hypersonic flight through the atmosphere is a few minutes because only that last bit of the trajetory is dipped in the atmosphere, rest is outside of it. And the heat shield of choice in this scenario is an Ablative Heat Shield, because that can withstand these temperatures, but that eats up the shield rather quickly. Another way is what ISRO uses in RLV: Carbon-Carbon CMCs in the nose.

But in the case of the HGV/boost-glide vehicle's cruise and terminal stages (flat part of the green trajectory), time spent in atmospheric hypersonic flight is much more than re-entry duration of a spacecraft/MaRV. So now, the materials on the HGV need to withstand that high temperature for much longer. So the usual ablative or C/C CMCs are not enough as these will completely erode in minutes and you need sustained flight. What is likely needed is an even better class of materials: Zirconium diboride or Hafnium diboride based CMCs.

Then there is the entire control problem for something flying the entire way while blanketed in a plasma sheath. There are ways of mitigating the comms. blackout due to the plasma, but not sure how useful it is for HGVs. Not sure how much work DRDO has done there, but its probably a lot considering HSTDV.

There is actually a third reason as well: pointy-ness <insert General Aladeen meme>. High lift-to-drag ratios are important for gliding, meaning they are important for HGVs, not for MaRVs. For high lift-to-drag ratio your nose needs to be pointy. Not blunt like the A1P MaRV or RLV. But pointy nose means the temperature at that tip is much higher (maybe a 1000 degrees higher) than on the blunt nose of a re-entring spacecraft/MaRV. That again leads to requirement of better materials.

Now your assertion is that these two things look so similar so why aren't they the same. I believe the Americans when they say theirs is an HGV (tho weird shape, I know) because they are probably world leaders in materials science right now. Especially when it comes to aerothermodynamic materials. I also believe our scientists when they do NOT call it an HGV because had this been an HGV, we would have seen tons of slides on this by now. But your assertion that it could be a secret NCA and DRDO are keeping from us and maybe its secretly an HGV, not a mere MaRV. To that I say "maybe, but I doubt it. Unless we can be sure that ISRO or DMRL have been working on the materials issue and have made headway."
Another reason is because if A1P RV was an HGV, the Americans who closely watch our tests, would have picked up on it and we might have been reading about it on some RAND Corp report clamouring for a Hypersonics Control Treaty.

Hence I conclude A1P RV is an MaRV, not an HGV. I have just one request. Please be gentle senpai.
 

gslv markIII

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Usual Farts and shits about Indian capabilities .
Leave it, I have even seen some commentators on the same website asking if India even have materials for the HSTDV that can survive aerothermodynamic heating.

No, we don't have any. It's not like we have an effing space program where we work with high temperature materials, right? :laugh:
 

porky_kicker

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They are different. Two reasons:-
  • Trajectory
  • Materials
First explain the above 2 assertions of yours

Trajectory - how did you come to know about the trajectory profile(s) of A1-P

Materials - how did you come to know about the materials used in A1-P RV

Unless you can validate the same your entire discourse fails
 

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