Author Topic: GSLV-Mk III - General Discussion  (Read 47344 times)

Offline johnxx9

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GSLV-Mk III - General Discussion
« on: 12/20/2014 08:04 PM »
This is the general discussion (not any mission specific) thread for the launcher. Launcher specs, capabilities, upgrades everything goes here.

Let me start with a puzzling spec on ISRO's new webpage for LVM3

Quote
Payload to LEO: 8,000 kg

The powerful cryogenic stage of LVM3 enables it to place heavy payloads into Low Earth Orbits of 600 km altitude.

Seems very less! Even the earlier reports of 10,000 kg to LEO was considered less by some accounts. Or do they mean a sun synchronous 600 km orbit?
« Last Edit: 06/09/2017 08:10 AM by input~2 »

Offline edkyle99

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Re: LVM3 - General Discussion
« Reply #1 on: 12/20/2014 08:28 PM »
This is the general discussion (not any mission specific) thread for the launcher. Launcher specs, capabilities, upgrades everything goes here.

Let me start with a puzzling spec on ISRO's new webpage for LVM3

Quote
Payload to LEO: 8,000 kg

The powerful cryogenic stage of LVM3 enables it to place heavy payloads into Low Earth Orbits of 600 km altitude.

Seems very less! Even the earlier reports of 10,000 kg to LEO was considered less by some accounts. Or do they mean a sun synchronous 600 km orbit?
10 tonnes is to a 200 km x 45 deg orbit. 

Since the rocket (whatever it is really called) is supposed to lift 4 tonnes to GTO using a high-energy upper stage, it seems possible that 10 tonnes is about right for LEO.  Titan 3C, a similarly sized rocket with "zero stage" solid boosters, but with more efficient core stage engines, could only lift about 12 tonnes to LEO.

 - Ed Kyle
« Last Edit: 12/20/2014 08:41 PM by edkyle99 »

Offline vineethgk

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Re: LVM3 - General Discussion
« Reply #2 on: 12/21/2014 07:49 AM »
Seems very less! Even the earlier reports of 10,000 kg to LEO was considered less by some accounts. Or do they mean a sun synchronous 600 km orbit?
10 tonnes is to a 200 km x 45 deg orbit. 

Since the rocket (whatever it is really called) is supposed to lift 4 tonnes to GTO using a high-energy upper stage, it seems possible that 10 tonnes is about right for LEO.  Titan 3C, a similarly sized rocket with "zero stage" solid boosters, but with more efficient core stage engines, could only lift about 12 tonnes to LEO.

 - Ed Kyle

Thanks for that clarification Ed. If I am not wrong, for typical manned missions, the spacecraft would be delivered to a 200km orbit, so a 10 tonnes payload capability to such an orbit should be more than sufficient for the manned spacecraft that ISRO wish to build.

I feel its a good thing that ISRO is not trying to call the new rocket as a GSLV now. I have seen many news reports already where the failures of GSLV-I/II series were being clubbed to the new rocket due to the confusion of similar names.

Online sanman

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Re: LVM3 - General Discussion
« Reply #3 on: 12/22/2014 12:28 AM »
It seems glaringly sloppy of ISRO to not keep absolute clarity on the name. Even on their own website, they refer to the same vehicle as both "GSLV Mark III" and "LVM 3"  :P

The ambiguity on even something as simple and basic as a name doesn't project ISRO in a positive way, and instead makes them look schizophrenic, or even cavalier and ad-hoc in their thinking. No other country's national space agency  exhibits these kinds of eccentricities.

Offline edkyle99

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Re: LVM3 - General Discussion
« Reply #4 on: 12/22/2014 01:46 AM »
It seems glaringly sloppy of ISRO to not keep absolute clarity on the name. Even on their own website, they refer to the same vehicle as both "GSLV Mark III" and "LVM 3"  :P

The ambiguity on even something as simple and basic as a name doesn't project ISRO in a positive way, and instead makes them look schizophrenic, or even cavalier and ad-hoc in their thinking. No other country's national space agency  exhibits these kinds of eccentricities.
During the 1960s, NASA initially identified its Apollo missions as "AS-201", "AS-202", "AS-501", and so on until the news media demanded a switch to "Apollo 1", "Apollo 4", etc.  Saturn C-1 became "Saturn I" ("I", not "1").  A later version was "Uprated Saturn I" for awhile, but was better known as "Saturn IB".  (Saturn C-1 itself was originally "Super Jupiter", then "Juno V".)

Cape Canaveral became Cape Kennedy.  Then it was re-renamed Cape Canaveral.  Unless we're talking about the City of Cape Canaveral itself, which was never named Cape Kennedy but was called Artesia before it was Cape Canaveral, but that's another story.

During the 1980s, NASA identified Space Shuttle missions as "STS-1", "STS-2" and so on until they switched to "STS-41B", "STS-41C" and the like.  Then a few years later the Agency switched back to the original numbering system. 

The first U.S. satellite was launched by a "Juno I".  Or was it a "Jupiter C"?  Or was it both?

Atlas III was Atlas IIAR first.  Titan IVA was Titan IV and before that it was Titan 34D-7.  And "Atlas V" is not really an "Atlas", since "Atlas" was a 10 foot wide balloon tank sustainer stage with a half-stage booster attached, both powered by Rocketdyne engines.  Ditto "Delta IV" and its link to the "Delta" name, which was not originally the name of a rocket at all but of a long-retired second stage, as in "Thor-Delta".  The stage was from the Vanguard program, so that the original rocket was called "Thor-Vanguard" for awhile unofficially before it started flying.  "Vanguard" itself was based on "Viking" (sort of a "Viking-Aerobee", really).  (Which means that if "Delta IV" was following the original naming convention it would be "Aerobee IV", or "Viking XX", or something.)

Orbital Sciences has renamed its "Taurus" rocket "Minotaur C", for some reason.  (OK, we know the reason.)

So ISRO isn't alone!

 - Ed Kyle
« Last Edit: 12/22/2014 01:17 PM by edkyle99 »

Offline Indo-guy

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Re: LVM3 - General Discussion
« Reply #5 on: 12/25/2014 02:12 AM »
It seems glaringly sloppy of ISRO to not keep absolute clarity on the name. Even on their own website, they refer to the same vehicle as both "GSLV Mark III" and "LVM 3"  :P

The ambiguity on even something as simple and basic as a name doesn't project ISRO in a positive way, and instead makes them look schizophrenic, or even cavalier and ad-hoc in their thinking. No other country's national space agency  exhibits these kinds of eccentricities.

There is no ambiguity at all .
It is going to be GSLV Mk III. No doubt about that .

The only reason to name this particular launch as LVM 3 is because ...this launch lacks active Cryogenic Upper stage ...so it is going to be sub orbital ...it is not going to reach Geo-synchronous orbit at all ...

so do you expect ISRO to name it GSLV when it is not going to reach geo-synchronous orbit at all ?

ISRO has been prudent in naming this mission as LVM III  ....

Offline Indo-guy

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Re: LVM3 - General Discussion
« Reply #6 on: 12/25/2014 02:15 AM »
It seems glaringly sloppy of ISRO to not keep absolute clarity on the name. Even on their own website, they refer to the same vehicle as both "GSLV Mark III" and "LVM 3"  :P

The ambiguity on even something as simple and basic as a name doesn't project ISRO in a positive way, and instead makes them look schizophrenic, or even cavalier and ad-hoc in their thinking. No other country's national space agency  exhibits these kinds of eccentricities.

It is your own lack of understanding  and not sloppiness on ISRO's part .

You should try to understand reasons first,  than  to come down so heavily and name calling ISRO .

You are really making mountain out of molehills ....

Careful before you heap insult on institute like ISRO out of your own ignorance .

Offline isro-watch

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Re: LVM3 - General Discussion
« Reply #7 on: 12/25/2014 03:01 AM »
Let us not make this personal and let us keep the discussion to technical aspects and facts about the launcher. People have right to criticize a public entity and by the way you are wrong here.

ISRO named the experimental mission as LVM3-X and not just LVM3. If you look better in the news reports, ISRO named their upcoming developmental flight as LVM3-D1

And, as sanman stated, there is ambiguity is the name of the launcher with ISRO naming it GSLM-MKIII in various places including on the launch vehicle (refer the launch blog on this forum), press reports and their website and then interchanging the names to LVM3 in some other reports

Offline abhishek

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Re: LVM3 - General Discussion
« Reply #8 on: 12/25/2014 03:37 AM »
So much fight over a name  :D ?

Didn't someone rightly say that what's there in a name,it's what inside that matters  ;D



10, 9, ignition sequence start 6, 5, 4, 3, 2, 1, 0, all engines running Lift off, we have a lift off, lift off

Offline vineethgk

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Re: LVM3 - General Discussion
« Reply #9 on: 12/25/2014 01:02 PM »
A few pretty basic questions in my mind.  ;D

Considering that the planned Kerolox stage for LVM3 is ground-lit, what was the reason behind ISRO not making the current L-110 ground-lit too? Does the increase in propellant weight and dead stage weight negate any payload advantages of an additional 1600 kN thrust at lift off? Would the rocket be hauling too much of dead weight when S-200s have burned out?

And, if these are indeed the reasons, would these problems be significantly lesser in the planned SC-160 Kerolox core? Due to higher Isp?

Offline johnxx9

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Re: LVM3 - General Discussion
« Reply #10 on: 12/25/2014 07:26 PM »
A few pretty basic questions in my mind.  ;D

Considering that the planned Kerolox stage for LVM3 is ground-lit, what was the reason behind ISRO not making the current L-110 ground-lit too? Does the increase in propellant weight and dead stage weight negate any payload advantages of an additional 1600 kN thrust at lift off? Would the rocket be hauling too much of dead weight when S-200s have burned out?

And, if these are indeed the reasons, would these problems be significantly lesser in the planned SC-160 Kerolox core? Due to higher Isp?

Costs come to mind as a reason. The earth storable propellants aren't cheap.

And, while design LVM3, ISRO's target was 4 ton GTO payload. Maybe they wanted to achieve with as least the amount earth storable propellant as they could. This configuration does that.

Remember that the L110 will have to burn for 100 seconds more if it were to be ignited on ground. That would need ~50% more propellant than the current config. For all we know, it might be one of the upgrades on LVM3 in the future.

There were 100s of alternatives for ISRO for 4 ton to GTO design.

One straightforward configuration would have been to upgrade the GSLV, by replacing the solid 1st stage with a liquid one. All they would have needed to do is cluster 3/4 Vikas instead of the current 2 on LVM3 and put it on the first stage (not easy as it sounds, but still at first though sounds better than developing a whole new rocket). Seems pretty straightforward considering they had all the other stages as its from the GSLV.

But, they chose this design. It seems like a good trade-off from the cost and complexity perspective.

Offline vineethgk

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Re: LVM3 - General Discussion
« Reply #11 on: 12/26/2014 06:09 AM »
Thanks. I thought it was more due to some design constraints in loading more propellants and making it ground-lit.

One straightforward configuration would have been to upgrade the GSLV, by replacing the solid 1st stage with a liquid one. All they would have needed to do is cluster 3/4 Vikas instead of the current 2 on LVM3 and put it on the first stage (not easy as it sounds, but still at first though sounds better than developing a whole new rocket). Seems pretty straightforward considering they had all the other stages as its from the GSLV.

Interestingly, this option you have mentioned will make the vehicle very similar to CZ-3B, if they were to additionally cluster two CE-7.5 engines in the upper stage. But I guess ISRO would have recognized it to be an evolutionary dead end when compared to the LVM3 design.

Offline vineethgk

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Re: LVM3 - General Discussion
« Reply #12 on: 01/04/2015 02:58 AM »
I'm quite intrigued by the difference in design philosophies of ISRO (and probably many old-school space agencies/enterprises) and SpaceX about what constitutes reliability and cost savings in a rocket design. For LVM3 and its successor ULV designs, ISRO has zeroed on less number of propulsion stages (but of different types - solid, liquid/kerolox, hydrolox) and use of massive solids as the key. While in case of Falcon 9 which has a similar payload capability and objective, SpaceX has chosen a design based on the use of more number of moderately powerful propulsion units of similar types, geared towards lowering costs through mass production and increasing the reliability through redundancy of numbers.

Even considering the fact that ISRO is yet to develop a kerolox engine for its use, I feel the major driver in this difference of approach could be that one is a government agency that relies on public funding and is consequently not too worried about costs (as a private company would), while the other is a start-up private enterprise that *has to* aim for reduction in production costs to ensure its success and long term viability. I admit ISRO isn't alone here, but going by the success that Falcon 9 had so far, has ISRO's design philosophy for LVM3 and ULV already become obsolete? Or is it too early to say?

Any thoughts?
« Last Edit: 01/04/2015 03:21 AM by vineethgk »

Offline edkyle99

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Re: LVM3 - General Discussion
« Reply #13 on: 01/04/2015 03:16 AM »
I admit ISRO isn't alone here, but going by the success that Falcon 9 had so far, has ISRO's design philosophy for LVM3 and ULV already become obsolete? Or is it too early to say?
It is too early to say, in part because LMV3 is still a couple of years away from flying with a live third stage.  It is too early to say because the reliability and true costs of the two systems will only be revealed over time.  Finally, it is too early to say because LMV3 looks to my eyes to have substantial performance growth possibilities that are not apparent for Falcon 9 v1.1.

 - Ed Kyle

Offline antriksh

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Re: LVM3 - General Discussion
« Reply #14 on: 01/05/2015 01:26 PM »
Hangover  ;D
@isro.org
« Last Edit: 01/05/2015 01:30 PM by antriksh »
Nasadiya Sukta:
Srishti se pehle sat nahin thaa, asat bhi nahin | Antariksh bhi nahin, aakaash bhi nahin thaa | chhipaa thaa kyaa, kahaan, kisne dhakaa thaa | us pal to agam, atal jal bhi kahaan thaa ||

From: 1st verse of 129th Hymn of the 10th Book of Rig Veda

Offline johnxx9

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Re: LVM3 - General Discussion
« Reply #15 on: 01/05/2015 01:38 PM »
I'm quite intrigued by the difference in design philosophies of ISRO (and probably many old-school space agencies/enterprises) and SpaceX about what constitutes reliability and cost savings in a rocket design. For LVM3 and its successor ULV designs, ISRO has zeroed on less number of propulsion stages (but of different types - solid, liquid/kerolox, hydrolox) and use of massive solids as the key. While in case of Falcon 9 which has a similar payload capability and objective, SpaceX has chosen a design based on the use of more number of moderately powerful propulsion units of similar types, geared towards lowering costs through mass production and increasing the reliability through redundancy of numbers.

Isn't SpaceX itself moving away from this model? Their next gen methox Raptor engine will generate around 5-6 MN of thrust. I guess they will replace the 9 engine cluster with this single engine.

Offline AChE

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Re: LVM3 - General Discussion
« Reply #16 on: 01/05/2015 04:12 PM »
Isn't SpaceX itself moving away from this model? Their next gen methox Raptor engine will generate around 5-6 MN of thrust. I guess they will replace the 9 engine cluster with this single engine.

No, replacing the 9 Merlins on stage one would eliminate the commonality between the first and second stage engine and make propulsive landing impossible.

Offline AChE

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Re: LVM3 - General Discussion
« Reply #17 on: 01/05/2015 04:40 PM »
I'm quite intrigued by the difference in design philosophies of ISRO (and probably many old-school space agencies/enterprises) and SpaceX about what constitutes reliability and cost savings in a rocket design. For LVM3 and its successor ULV designs, ISRO has zeroed on less number of propulsion stages (but of different types - solid, liquid/kerolox, hydrolox) and use of massive solids as the key. While in case of Falcon 9 which has a similar payload capability and objective, SpaceX has chosen a design based on the use of more number of moderately powerful propulsion units of similar types, geared towards lowering costs through mass production and increasing the reliability through redundancy of numbers.

Even considering the fact that ISRO is yet to develop a kerolox engine for its use, I feel the major driver in this difference of approach could be that one is a government agency that relies on public funding and is consequently not too worried about costs (as a private company would), while the other is a start-up private enterprise that *has to* aim for reduction in production costs to ensure its success and long term viability. I admit ISRO isn't alone here, but going by the success that Falcon 9 had so far, has ISRO's design philosophy for LVM3 and ULV already become obsolete? Or is it too early to say?

Any thoughts?

Too early to say: massive segmented solids have an iffy record wrt cost. Titan IV and H-II, Shuttle to some extent. Europe is moving away from them in favor of monolithic for A6, indicating the segmented solids were a cost driver for A5. Production costs in India might make them a reasonable choice, worked for PSLV.

The only alternative that comes to mind given ISRO experience would be essentially an A4 clone: multi-Vikas stage 1, single Vikas stage 2, cryo stage 3. But hypergols are expensive, and this would require several hundred tonnes more than LVM3. And (haven't done the math) probably 8 Vikas on stage 1 to match LVM3 performance. So given what ISRO has to work with (experience in solids, Vikas, and cryogenics) LVM3 seems like a reasonable design: propellants are burned in order of Isp, only 3 liquid engines per vehicle, and the only liquid engine development required is the CE-20.

Offline TrevorMonty

Re: LVM3 - General Discussion
« Reply #18 on: 01/05/2015 05:39 PM »
They have a RD181/193 class kero engine in development.

Online Lars-J

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Re: LVM3 - General Discussion
« Reply #19 on: 01/06/2015 06:16 AM »
Hangover  ;D
@isro.org

Thanks, it is great to see some higher resolution images!

Tags: GSLV Mk3 LVM3