ISRO General News and Updates

[Vamsi]

GSLV is the Frankenstein of space launch vehicles.

(RANT INCOMING)



And let's not talk about the COMPLEX non-restartble staged combustion upper(vaccum) stage hydrolox engine (c.e7.5) which is near impossible to be properly tested on a test stand in ground settings. And took us 5 failed/partially launches over a decade to overcome.

(RANT OVER)

They tested both CE-7.5 & CE-20 on ground using their high altitude test facility, but at the time of D3 flight they didn't have HATF, but after that they built one

 

[pipebomb]

Unnecessary rant

ISRO's original plan for GSLV is to have L220 core powered by 4 Vikas engines just like in Ariane-4, but they didn't had the test stand to test clustered engines.

Now why didn't they build test stand to test clustered engines?? Answer is, Nambi Narayanan sir did proposed to build one,but the then ISRO chief Satish Dhawan sir rejected his proposal.

'Unnecessary', that could be said about any or all rants. I am not criticizing ISRO per se here. To me Satish sir is as much ISRO as Nambi sir.

Ofcourse we always had 'plans' (for eg. the high altitude engine test facility for GTRE near Nagarjuna Sagar Dam) but how many of these 'plans' come to fruition. A rant or two wouldn't harm anyone IMHO. But I appreciate your response.

 

[pipebomb]

They tested both CE-7.5 & CE-20 on ground using their high altitude test facility, but at the time of D3 flight they didn't have HATF, but after that they built one

To my lay knowledge one can test different parts/sections of a gas generator engine separately to a satisfactory level of certainty, unlike a stage combustion engine which needs to be tested as a whole. It appears to me as an unnecessary complexity for a upperstage engine and that too a hydrolox.

 

[Vamsi]

To my lay knowledge one can test different parts/sections of a gas generator engine separately to a satisfactory level of certainty, unlike a stage combustion engine which needs to be tested as a whole. It appears to me as an unnecessary complexity for a upperstage engine and that too a hydrolox.

CE-7.5 is reverse engineered version of Russian KVD-1, hence staged combustion, while CE-20 is India' first & only true indigenous engine, upcoming 100ton thrust Methalox engine might be the 2nd true indigenous engine if everything goes as planned

 

[pipebomb]

CE-7.5 is reverse engineered version of Russian KVD-1, hence staged combustion, while CE-20 is India' first & only true indigenous engine, upcoming 100ton thrust Methalox engine might be the 2nd true indigenous engine if everything goes as planned

Is the methalox engine stage combustion ?

 

[AnantS]

Is the methalox engine stage combustion ?

yes because it needs to be throttable

 

[pipebomb]

yes because it needs to be throttable

Merlin 1d is throttable and that's a gg cycle

 

[Vamsi]

Is the methalox engine stage combustion ?

yes because it needs to be throttable

Gas Generator as per the RTI reply

 

[AnantS]

Gas Generator as per the RTI reply

Oh!

 

[pipebomb]

Gas Generator as per the RTI reply

 

[pipebomb]

Gas Generator as per the RTI reply

Still doesn't have the confidence to design their own staged combustion engine after building two soviet designs from blueprint handouts.

 

[Vamsi]

Still doesn't have the confidence to design their own staged combustion engine after building two soviet designs from blueprint handouts.

staged combustion has long development cycle, we started work on SCE-200 in 2007 & the engine will fly NET 2026,its also complex & maintenance heavy, so GG cycle engine is the way to go, when you want to reduce development timeline (especially if you want NGLV before 2035), increase reliability, & maintenance friendly....

side note: French still doesn't have a staged combustion engine, all their engines are GG cycle or Expander cycle, while their upcoming Methalox engine too shall be a GG cycle engine

 

[pipebomb]

staged combustion has long development cycle, we started work on SCE-200 in 2007 & the engine will fly NET 2026,its also complex & maintenance heavy, so GG cycle engine is the way to go, when you want to reduce development timeline (especially if you want NGLV before 2035), increase reliability, & maintenance friendly....

side note: French still doesn't have a staged combustion engine, all their engines are GG cycle or Expander cycle, while their upcoming Methalox engine too shall be a GG cycle engine

Long development cycle is a good enough reason/excuse only if you are attempting it first time which is not the case here. For example look at our missile development a decade ago and compare it today's scenario.

 

[Vamsi]

Long development cycle is a good enough reason/excuse only if you are attempting it first time which is not the case here. For example look at our missile development a decade ago and compare it today's scenario.

They have built more than 130 Vikas engines till date, designed & developed CE-20 on their own without any foreign help, the expertise they have gained from Vikas & CE-20 is more than what they have gained from CE-7.5 & SCE-200, hence it is logical to assume that they have gained more confidence in successfully developing a Methalox engine using GG cycle.

 

[NoobWannaLearn]

Don't know where to post it mods move it if needed to appropriate thread but this is a great achievement

 

[pipebomb]

side note: French still doesn't have a staged combustion engine, all their engines are GG cycle or Expander cycle, while their upcoming Methalox engine too shall be a GG cycle engine

I just found out that even the New Zealand based startup Rocket Lab has changed their Archimedes' engine design from gg cycle to ORSC.

And please don't forget that they build their rockets out of composite unlike ours with steel.

Wonder why they took the 'lengthy' route given their inexperience ?

 

[Vamsi]

I just found out that even the New Zealand based startup Rocket Lab has changed their Archimedes' engine design from gg cycle to ORSC.

And please don't forget that they build their rockets out of composite unlike ours with steel.

Wonder why they took the 'lengthy' route given their inexperience ?

They will be benefitted from the already existing vast test data & expertise from US. Although it's a Newzealand company in name, by soul it's American

For eg: SpaceX's Merlin engine is based on a pre-existing American engine, it's not a completely new development, similarly Americans have built two FFSC engines before the Raptor engine, the test data from those two engine would have definitely played a part in the development of Raptor.

 

[pipebomb]

side note: French still doesn't have a staged combustion engine, all their engines are GG cycle or Expander cycle, while their upcoming Methalox engine too shall be a GG cycle engine

Another thought just occurred to me that French didn't have any experience in developing a stage combustion cycle engine unlike us( CE-7.5 and now SCE200). Nor did they get any blueprints of any sort from Americans or Soviets, atleast to my knowledge.

Apologies for late reply.

 

[Vamsi]

What the F**k??? this will do us no good, it will only stop us

Joining ISS, curtailed Europe's & Japan's own Human Spaceflight programmes, similarly joining Artemis Accords will only slow our Human Space Programme

 

[AnantS]

What the F**k??? this will do us no good, it will only stop us

Joining ISS, curtailed Europe's & Japan's own Human Spaceflight programmes, similarly joining Artemis Accords will only slow our Human Space Programme

So we have agreed to subsidise US moon dream? Are getting any benefit out of it in terms of technologies shared? India though shall get some exposure to process and teknics involved.