Indian Space Programme Discussion

[TSJones]

^^
No no. It cant finance the projects..........so Iam looking for the right word here...........ummmmmm.......yes broke ya that is the word. It is easy to say that it has x billion budget. But NASA pays very high price for goods and service for the projects. Similarlywhen people say that USA spent 20 billions in Afganistan........not impressed. You can lower your TFTness and install simple water purification plant that gives water in cents or theycan import water from california at 10USD/lt. IMONASA achived great things when it was concentrating on science but for last 20 years they are just concentrating on minor side rag tag discoveries which are the result of da or imagery obtained from pasr projects.
Sorry but typing from tablet is really painfull so i stop here.

You couldn't be more wrong. In the last 20 tears we've had 3 rovers on Mars, 2 are still active, with more missions to Saturn and Pluto, an orbiting telescope(s)(Hubble) with one telescope being sent out beyond the moon in a couple of years plus multiple competitions for service contracts to the ISS by private companies with one entry being a lifting body space plane (we have three otherm space planes but they are operated by the DoD so they don't count). Plus we have many other ongoing projects that I simply can't list because it's just too much for this forum. All of this stuff going on plus there are mandated congressional programs for a BEO capsule and the SLS rocket which will be tested in 2017. Plus we recently built a new rocket engine, the first in 10 years. So broke? Nah, not broke. Not when we dwarf everybody else's spending in space.

Oh, also in the last 20 years we've added a space port in Alaska Kodiak Island, another one in Virginia and added facilities to another in New Mexico. Plus there is a launch facility at Mojave, Ca. and SpaceX is building a launch at Vandenberg AFB on the coast of Ca for it's new heavy rocket. True, it's not NASA but it still reflects on America society's efforts in the space arena.

[Sagar G]

^^^ Done showing how big NASA's d*ck is or have more to show ???

[shyamoo]

I think TSJones was just responding to rsingh's comment.

No need to bring out the ruler!!!

Besides, ISRO has shown what it can do with an SDRE sized one

[Raja]

IMONASA achived great things when it was concentrating on science but for last 20 years they are just concentrating on minor side rag tag discoveries which are the result of da or imagery obtained from pasr projects.
Sorry but typing from tablet is really painfull so i stop here.

What is your rather uninformed "opinion" based on? Surely, not on any real facts as NASA is still the main source of discoveries when it comes to humanity's increasing understanding of the universe. Learn to give credit where its due.

However, space projects and discoveries that await us are getting more and more complicated. No single country can ever hope to have sufficient budget. Cooperation will become increasingly important going forward. Neither China nor India are going to be able to replace NASA of the past. Everyone is going to have to learn to work together. Luckily, scientists tend to not be as nonsensical as some of the rhetoric around here.

[Indranil]

It is really funny about how some posters here measure what ISRO can do based on what NASA has done and vice-versa.

[Vipul]

Ministry of Defence tasked to recruit crew for ISRO's 'Man to Moon' mission.

The Ministry of Defence (MoD) has been tasked to recruit crew for ISRO's "ambitious" Man to Moon Mission, Air Marshal A K Behl, Director General, Medical Services (Air) Friday said.

MoD and ISRO have signed an MoU for the project. "We have collaborated with ISRO a couple of years ago," he said.

The Director General for Armed Forces Services (DGAFS), who is looking after the project, is also also supposed to asses whether the crew can maintain the spacecraft well and come back safely.

"Man to Moon is an ambitious project started by the ISRO.

Since the Indian Air Force has domain expertise in aviation and in other aspects related to space, we have collaborated with them. The Institute of Aviation Studies Bangalore is also involved in this project," Behl added.

Rakesh Sharma, a former Indian Air Force pilot who flew aboard Soyuz T-11 as part of the Inter-cosmos programme by the USSR was the first Indian to travel in space.

[venkat_r]

Hmmm - ISRO with its selective projects has shown its innovation and accomplishments.

No comparison with NASA now or even in the next few decades. ISRO can only dream to have budgets or projects like NASA - Space projects are complex and require funding/technology beyond the reach of any one country in the future. Wisely India has chosen the path of co-operation and hopefully as it continues will see some interesting projects in the future. Would be great to galvanize interest in space and universe among the next generation in India.

[member_28108]

It is indeed amusing to see jingoism- I think each country has to march to its own drummer! There have been many wonderful successes by NASA and it has matured into a stable system and is a leader in interplantery exploration etc. India has taken a different path but is getting therewith its own methodology and hopefully with the development of a cryogenic engine will overcome a huge stumbling block.

[Varoon Shekhar]

"and hopefully with the development of a cryogenic engine will overcome a huge stumbling block."

This will be watched closely and anticipated very eagerly! ISRO needs a major breakthrough in launch vehicle technology. The last one was really with the first successful PSLV launch, back in 1994. Since then, there have been some impressive modifications of the PSLV, which have enhanced its capability. But no fundamental advancement in launch technology as such.

[SSridhar]

Folks, just remember that this forum is about Indian space programme. Do not discuss extraneous matter and incur board warning.

[member_28108]

It is withoput doubt that mastering cryogenic technology is very sorely needed. Verner Von Braun quickly relaized its necessity and a lot of research went to it .Unfortunately we got stalled.Now that we any way have ICBM capability there may not be so much extraneous stumbling blocks(hopefully) but at the end of the day in-house learnt technology if successful is more important. Failure is a stepping stone for success and hopefully we have learnt much from our failures..No country has rung a space program without failures.The important thing is what did we learn from it. Waiting with bated breath for the GSLV launch.It can make a world of a difference to our program.

[rsingh]

IMONASA achived great things when it was concentrating on science but for last 20 years they are just concentrating on minor side rag tag discoveries which are the result of da or imagery obtained from pasr projects.
Sorry but typing from tablet is really painfull so i stop here.

What is your rather uninformed "opinion" based on? Surely, not on any real facts as NASA is still the main source of discoveries when it comes to humanity's increasing understanding of the universe. Learn to give credit where its due.

However, space projects and discoveries that await us are getting more and more complicated. No single country can ever hope to have sufficient budget. Cooperation will become increasingly important going forward. Neither China nor India are going to be able to replace NASA of the past. Everyone is going to have to learn to work together. Luckily, scientists tend to not be as nonsensical as some of the rhetoric around here.

Sir let me to enligten you
Nasa has no rocket capable of sending man in space today.talking of today
Half of the projects given by John Sir are private initiative so budget of XXbillion does notcount here
Even main US media is very clear about NASAs problems. So inform yourself and give due credit
I have happen to have another pair of glasses. I speak Russian. Belive me they have achived much more then they are given credit for. NASAs annoncments about habitable plantes and better huble pictures are big joke among the people who know. These were predicted in 80s
I do not compare ISRO with NASA. I fan of NASA since i saw photo of man on moon on the first page in 1972. ISRO has
done quit well given it small budget and sanctions.
Chinese have done even better.
MODs please have some patience

[SSridhar]

No, MODS do not have patience. Warning issued.

[Gagan]

Re Manned Mission to the Moon
I think this is a great step by ISRO - MOD

The only possible people that India can send will be IAF personnel.
We are looking at a flight somewhere like 5-10 yrs down the line. Preparations have to be made starting today.
The first step will be sending animals into LEO and recovering them
Then human space flight into LEO, space walks etc.
Then the human moonshot.

GSLV-II is the minimum that will be needed for anything which involves a human spaceflight.

The ground facilities for training of astronauts, the Space capsules, the soyuz type modules etc have to be worked on. The chinese used a russian soyuz module for their human space flights so far.

India has a lot of catching up to do - that cryogenic engine delay is to blame for us lagging behind the chinese now.

[Vipul]

Isro clears GSLV D5 launch; countdown from 4 January.

Decks were cleared for the 5 January launch of India’s rejuvenated indigenous cryogenic engine- fitted GSLV-D5 carrying communication satellite GSAT-14 from the spaceport of Sriharikota with Isro’s Launch Authorisation Board (LAB) giving its nod for the key mission on Friday.

A 29-hour countdown for the launch is set to commence on 4 January next, Indian Space Research Organisation (ISRO) sources said.

“The Launch Authorisation Board has cleared the GSLV D5 launch for 5 January. A 29-hour countdown is set to commence on 4 January at around 11 am,” an Isro official told PTI.

GSLV D5 would be launched at 4.18 pm from Satish Dhawan Space Centre (SDSC) at Sriharikota, about 100 km from Chennai.

The Launch Authorisation Board met at the SDSC.Following the clearance, the launch vehicle would be moved to the launch pad tomorrow around 6 am, the sources said.The launch vehicle had already been integrated with the 1,980 kg GSAT 14.

GSLV D5’s mission was aborted at the eleventh hour on 19 August this year due to a fuel leak in its second stage.

Fuel tank made of aluminium alloy called Afnor 7020 tended to develop crack over a period of time and the leak was blamed on it following which the rocket had been rejuvenated.

The GSLV is designed to inject its passenger spacecraft into the intended Geosynchronous Transfer Orbit (GTO) with a combination of solid, earth-storable liquid and cryogenic propellants in it’s first, second and third stages, respectively.

The lift-off has been further augmented by the four earth- storable liquid strap-on boosters attached to the first stage, they said.

[Anant]

Can someone tell me why the upper stage of the GSLV is cryogenic (CUS)? Other countries have used cryogenic engines on earlier stages in a rocket to lift heavy loads. I would love to know the rationale behind this configuration. Thank you and good luck to ISRO.

[member_25400]

Can someone tell me why the upper stage of the GSLV is cryogenic (CUS)? Other countries have used cryogenic engines on earlier stages in a rocket to lift heavy loads. I would love to know the rationale behind this configuration. Thank you and good luck to ISRO.

Anant, it is incorrect to state that cryogenic engines are used mainly for first stages. There are more cryogenic upper stage rocket engines flown than there are first stages.

Every single cryogenic engine listed here as the first developed by the country (US R-10, and J-2, Japanese LE-5 engine flew in 1977, the French HM-7 in 1979 and the Chinese YF-73 in 1984.) were upper stages. Ref : http://www.thehindu.com/opinion/lead/th ... 397441.ece

In fact, if you look at wikipedia flown rocket engines/motors (at bottom listed against cryogenic engines) https://en.wikipedia.org/wiki/YF-73, then you can see that RL10, RL-60, J-2, LE5 variants, HM-7, YF-73, Yf-75 and RD-0146 (2nd stage) are all upper stages. Only RS68, RS25 (SSME, now retired), RD-120 (retired), Vulcain and YF-77, and LE-7 (some in development) are first stages.

If you refer the hindu article, the indian goal was to provide the simplest way of transforming the PSLV to the GSLV. The study commision (Cryogenic Study Team) that evaluated the alternatives recommended the development of upper cryogenic stage. The russian engine selected and the later indian developments are therefore aimed at this.

The GSLV uses a 139 tonne solid rocket first stage and Vikas engines for second stage, both derived from PSLV (which uses similar . Thus they could re-use some of the technology developed for PSLV, which would have had the goal of reduced development cost, risk, timelines (ha!), etc. Solid rockets cannot be throttled, but have high thrust and hence are more suitable for 1st stage/boosters (or all solid fueled missiles). Vikas engine is a well proven engine derived from the french viking technology (that was already known then).

Liquid fueled engines have ability to be throttled (and in some cases to be re-started). Cryogenic engines have greater mass flow/thrust, but require foam insulation (which brings its own risk,- witness foam breaking off and destroying Columbia) and more importantly make it difficult to store for long periods, and handle.

On the flip side, UDMH/Nitrogen tetroxide based fuels (Viking engine) are toxic, carcinogenic, and can explode in the presence of oxidizers. But they can be stored and have high density.

TLDR: More cryogenic upper stage engines flown than first stage engines. First cryogenic engines of US, France, Japan, China, are all upper stages. Cryogenic upper stage for GSLV picked as simplest way to transform PSLV to GSLV (to re-use PSLV technology)

[member_25400]

that cryogenic engine delay is to blame for us lagging behind the chinese now.

Chinese have much longer history of rocket engine development, (military and civilian,) have more infrastructure/more money in rocket/space program development, with coherent long range programme and have had russian help in far past. India would anyway be catching up, (but agreed cryogenic engine delay puts us further behind. )

[abhishek-nayak]

Can someone tell me why the upper stage of the GSLV is cryogenic (CUS)? Other countries have used cryogenic engines on earlier stages in a rocket to lift heavy loads. I would love to know the rationale behind this configuration. Thank you and good luck to ISRO.

The cryogenic engine of India i.e C 7.5 produces a thrust of only 73 KN which is not enough for the initial lift off.For that we have solid rockets which produces 4000+ KN of thrust.

[Suraj]

The Chinese benefited greatly from the US witchhunt against Qian Xuesen in the early 1950s. As soon as he was released by authorities, China wooed him back and provided him everything he needed to kickstart their rocket and missile program. If we want faster results we have to invest much more money and talent into engineering development.

[PratikDas]

The GSLV D5 brochure has this nugget: "Inclusion of Video Imaging System to monitor lower shroud movement during various phases of flight."

We might get that downward pointed camera view after all!

Apologies if this was posted earlier. Didn't find it with the search function.

[merlin]

Data point - it appears that GAGAN is operational. Last week I was travelling and used my Garmin GPS and noticed DOP of 2.2m as against the best 7m or so obtained earlier with comparable open view of the sky all around the car. And the GPS said differential mode so although the GPS is designed for augmentation with WAAS only maybe it works with GAGAN signals too. At least I have never seen such low DOP with my GPS.

[member_28348]

i've a doubt about PSLV: since all strap-ons and 1st stage are solid fuel engines, how does PSLV make the "pitch" maneuver? the solid engine nozzles could be gimbled too? it doesnt even have fins to aerodynamically maneuver.

[member_28108]

Quote from wikipedia
Pitch and yaw control of the PSLV during the thrust phase of the solid motor is achieved by injection of an aqueous solution of strontium perchlorate in the nozzle to constitute Secondary Injection Thrust Vector Control System (SITVC). The injection is stored in two cylindrical aluminum tanks strapped to the solid rocket motor and pressurized with nitrogen. There are two additional small liquid engine control power plants in the first stage, the Roll Control Thrusters (RCT), fixed radially opposite one on each side, between the triplet set of strap-on boosters. RCT is used for roll control during the first stage and the SITVC in two strap-on motors is for roll control augmentation.

[SriKumar]

The GSLV D5 brochure has this nugget: "Inclusion of Video Imaging System to monitor lower shroud movement during various phases of flight."
Apologies if this was posted earlier. Didn't find it with the search function.

http://isro.org/gslv-d5/pdf/brochure.pdf]brochure
Well, the shroud was the main cause of the failure of the previous launch as per the failure committee report, so I would assume they would be doubly watchful of the entire shroud this time around. The brochure has a lot of good info. in it. One interesting thing is that the 2nd stage ignition happens before the first stage separation, whereas the CUS ignition takes place after 2nd stage separation.

[member_28348]

Pitch and yaw control of the PSLV during the thrust phase of the solid motor is achieved by injection of an aqueous solution of strontium perchlorate in the nozzle to constitute Secondary Injection Thrust Vector Control System (SITVC). The injection is stored in two cylindrical aluminum tanks strapped to the solid rocket motor and pressurized with nitrogen. There are two additional small liquid engine control power plants in the first stage, the Roll Control Thrusters (RCT), fixed radially opposite one on each side, between the triplet set of strap-on boosters. RCT is used for roll control during the first stage and the SITVC in two strap-on motors is for roll control augmentation.

thank you very much sir.
is this the same with GSLV too? or the four liquid fuel engines could gimble their nozzles for it?

[member_28108]

The s200 sold rocket boosters of GSLV Mk III has flex nozzles.
The GSLV Mk2 shares the same S139 solid fueled stage

[disha]

Can someone tell me why the upper stage of the GSLV is cryogenic (CUS)? Other countries have used cryogenic engines on earlier stages in a rocket to lift heavy loads. I would love to know the rationale behind this configuration. Thank you and good luck to ISRO.

Raw Thrust vs. ISP

Put it this way, a cryo stage is more efficient but less powerful like a desi buffalo or vechur cow gives only 2-4 ltrs of milk per day but can eat dry grass., while the solid stage can provide maximum raw power but least efficient - like an imported holstein cow giving some 20-40 ltrs per day but requires specialized nutrition.

80% of Space shuttle's thrust came from the solid rocket boosters on the side. Put it other way, solid stages are reliable, can be scaled up and provide very large thrusts and innovations like vectoring nozzles and customized grain size it is going to continue far into future. Its demise is premature.

Even GSLV MKIII is configured around 200 ton solid rocket boosters.

[Anant]

Thank you everyone for the primer on the Cryogenic Upper Stage. I always learn something from the experts. I wish ISRO the best of luck on the 5th of January. Good luck!

[member_28108]

Clearly explained in Wikipedia-
During World War II, when powerful rocket engines were first considered by the German, American and Soviet engineers independently, all discovered that rocket engines need high mass flow rate of both oxidizer and fuel to generate a sufficient thrust. At that time oxygen and low molecular weight hydrocarbons were used as oxidizer and fuel pair. At room temperature and pressure, both are in gaseous state. Hypothetically, if propellants had been stored as pressurized gases, the size and mass of fuel tanks themselves would severely decrease rocket efficiency. Therefore, to get the required mass flow rate, the only option was to cool the propellants down to cryogenic temperatures (below −150 °C, −238 °F), converting them to liquid form. Hence, all cryogenic rocket engines are also, by definition, either liquid-propellant rocket engines or hybrid rocket engines.[2]

[member_24146]

ISRO's Press Release: No Man to Moon Mission

December 31, 2013

Media reports on "Manned Mission to Moon"

Indian Space Research Organisation (ISRO) has entered into a Memorandum of Understanding (MOU) with Institute of Aerospace Medicine (IAM), Indian Air force, Bangalore in March 2009 to carry out i) Basic research/studies on Human Physiological and Psychological requirements for Human Space Flight crew and ii) For augmenting/updating existing facilities at IAM to cater to ISRO's Human Space Flight Programme as a pre project Research & Development activity.

ISRO currently does not have any project on "Man to Moon". The scope of the MOU between ISRO and IAM does not envisage recruitment of crew for ISRO.

[vishvak]

Funny how ISRO has to explicitly state what is not on its plate currently in its exact final form or details of what's not therein as well ie not envisaging something within its scope. Thanks to naysayers who may see mission to mars as one saperate project with scope not envisaging something, and manned space flight not envisaging something, and then.. and then whatever.

[venkat_r]

Done right to stomp such news in its bud. IMHO, man to moon is nowhere in sight for ISRO. Chandrayaan1 in 2008 and nothing till 2016+. That in itself is a pity and a dream killer - should have gotten one or two more missions by now, atleast an orbiter as the Russian lander for Chandrayaan II failed. But lack of proper launchers (GSLV) is also an issue to launch moon landers and rovers. Need coherent strategy and serious launch power - Cannot be a single trick pony for long. So lot rides on this GSLV mission.

[Prasad]

Some info from the ISRO facebook page -

Mission Status: GSLV-D5/GSAT-14
We are all set for the launch, the launch rehearsal has been successfully completed a few hours back, all results are apparently normal...

[ravar]

The s200 sold rocket boosters of GSLV Mk III has flex nozzles.
The GSLV Mk2 shares the same S139 solid fueled stage

Not sure whether GSLV Mk1 and 2 share the SITVC. Remember that its core shuts down earlier at 100s but the liquid-strap-ons shut down only at 148s. So, 48s of unguided flight seems improbable. The core (lit/shut down phases) may be actually 'piggy-backing' on the gimbal control of the strap-ons?

Moeover, when the four strap-ons are anyway designed to be gimballed, by virtue of those being liquid engines, it doesn't make sense for SITVC which would be redundant?

Some gurus may enlighten.TIA

[nachiket]

A couple of questions for the Gurus here:

1. Can the S200 boosters be fitted to the GSLV MKII to convert it into a sort of MK2.5 with a lifting ability in between that of the MkII and III? The MKIII will take quite some time to come online yet and this could offer an interim heavier option, if it is indeed possible.

2. Why is the MKIII 2 stage instead of 3 like the MKII? I realize that its first stage consists of two Vikas engines so it is like having 2 MKII second stages. But wouldn't having the S139 or another stage before that be even better, to provide and even greater lifting ability?

[SaiK]

Will 2014 see a 20-year-old Indian space dream come true? January 5 should tell whether years of ISRO’s toil and tears will fructify and usher India into a select club of countries — those with their own cryogenic rocket engine technology, which can launch their communication satellites from their soil.

Space agency ISRO, flush from launching its Mars Orbiter Mission, will face its acid test on Sunday when it flies the GSLV-D5 launch vehicle with the indigenously built cryogenic upper third stage. To succeed, the launcher must place GSAT-14, a two-tonne-class satellite, in the planned orbit.

ISRO Chairman K. Radhakrishnan told The Hindu that the GSLV flight with an indigenous cryogenic stage would be a priority mission for 2014.

The upcoming launch is said to be extremely vital for the organisation morally and operationally. The first such bid failed in April 2010. A second attempt was called off in August 2013, an hour before the launch, after a fuel leak was detected. In the last four or so months, the organisation had done everything to ready a “refurbished” vehicle, Dr. Radhakrishnan said. Significant changes were made, including new fuel tanks, systems and material, based on the recommendations of the K. Narayana committee that went into the August leak episode.

The teams started re-assembling the current vehicle on October 18, 2013. The three-stage GSLV rocket has a first stage (S139) propelled by solid fuel; its four strap-on (L40) boosters use liquid fuel. The second stage GS2 uses liquid propellants. The third cryo stage uses liquid hydrogen and liquid oxygen. While D5’s cryo stage was found healthy after August, ISRO had to work anew on the other two.

Dr. Radhakrishnan said: “We got a new S139 solid first stage. Its four liquid strap-on stages have a lot of avionics, so we refurbished them at Mahendragiri and Hindustan Aeronautics Ltd. We also made a new second stage. When the launch was called off in August, the liquid stage had to be drained of fuel and washed with much water. This might have affected the electronics systems, so we replaced them, too.”

More importantly, the fuel tank material has been changed, fully phasing out the traditional but corrosion-prone aluminium-zinc combine, called AFNOR 7020. The new alternative, aluminium-copper alloy called AA2219, is now the material for all PSLV and GSLV tanks.

http://www.thehindu.com/news/national/w ... 527391.ece

[member_28108]

The s200 sold rocket boosters of GSLV Mk III has flex nozzles.
The GSLV Mk2 shares the same S139 solid fueled stage

Not sure whether GSLV Mk1 and 2 share the SITVC

What are you exactly referring to as "SITVC" Acronymns are better expanded to avoid congusion !!

It does share the same Ist stage (except for the initial launches).One of the things was the GSLV reuses those components of the PSLV that it can use.


Version Strap-On Stage 1 Stage 2 Stage 3 Stage 4
PSLV (1) 6 × PS0M / S-9 PS1 / S-125 PS2 (L-37.5) / Vikas PS3 / S-7 PS4 (L-2) / 2 ?
PSLV (2) 6 × PS0M / S-9 PS1 / S-138 PS2 (L-40) / Vikas PS3 / S-7 PS4 (L-2) / 2 ?
PSLV (3) 6 × PS0M / S-9 PS1 / S-138 PS2 (L-40) / Vikas PS3 / S-7 PS4 (L-2.5) / 2 ?
PSLV-CA - PS1 / S-138 PS2 (L-40) / Vikas PS3 / S-7 PS4 (L-2.5) / 2 ?
PSLV-XL 6 × PS0M-XL / S-12 PS1 / S-138 PS2 (L-40) / Vikas PS3 / S-7 PS4 (L-2.5) / 2 ?
PSLV-HP 6 × PS0M-XL / S-12 PS1 / S-139 PS2 (L-42.5) / Vikas HPS3 / S-? HPS4 (L-?) / 2 ?
PSLV-3S - PS1 / S-139 HPS3 / S-? HPS4 (L-?) / 2 ? -
GSLV Mk.1 4 × L-40 / Vikas GS-1 / S-125 GS-2 (L-37.5) / Vikas GS3 (C-12) / KVD-1M -
GSLV Mk.1 (2) 4 × L-40H / Vikas GS-1 / S-139 GS-2 (L-37.5H) / Vikas GS3 (C-12) / KVD-1M -
GSLV Mk.1 (3) 4 × L-40H / Vikas GS-1 / S-139 GS-2 (L-37.5H) / Vikas GS3 (C-15) / KVD-1M -
GSLV Mk.2 4 × L-40H / Vikas GS-1 / S-139 GS-2 (L-37.5H) / Vikas GS3 (CUS-12) / CS -
GSLV Mk.2A 4 × L-40H / Vikas GS-1 / S-139 GS-2 (L-37.5H) / Vikas GS3 (CUS-15) / CS -
GSLV Mk.2C 4 × L-40H / Vikas GS-1 / S-139 GS-2 (L-40H) / Vikas GS3 (CUS-15) / CS PAM-G

[symontk]

The s200 sold rocket boosters of GSLV Mk III has flex nozzles.
The GSLV Mk2 shares the same S139 solid fueled stage

Not sure whether GSLV Mk1 and 2 share the SITVC. Remember that its core shuts down earlier at 100s but the liquid-strap-ons shut down only at 148s. So, 48s of unguided flight seems improbable. The core (lit/shut down phases) may be actually 'piggy-backing' on the gimbal control of the strap-ons?

Moeover, when the four strap-ons are anyway designed to be gimballed, by virtue of those being liquid engines, it doesn't make sense for SITVC which would be redundant?

Some gurus may enlighten.TIA

there are no sitvc's in GSLV. Liquid strapons does the job

[symontk]

What are you exactly referring to as "SITVC" Acronymns are better expanded to avoid congusion !!

It does share the same Ist stage (except for the initial launches).One of the things was the GSLV reuses those components of the PSLV that it can use.

SITVC is Secondary Injection Thrust Vector Control. In PSLV, it injects some chemicals which changes the burn flow direction