GSLV MkII design, development, operations

[Proponent]

According to astronautix.com, the original GSLV featured four UDMH/N2O4 liquid boosters strapped onto a solid-propellant first stage:  http://www.astronautix.com/lvs/gslv.htm.

Why the heck would you want liquid strap-ons, with an Isp of 281 s and a thrust-to-weight ratio of 1.6, on a solid core stage with an Isp of 266 s and a ratio of 3.2?

Another weird thing is that the core stage burns out after 93 s, whereas the LRBs burn for 159 s.  So you have to drag the 28 metric tons of the burned-out core stage along for about a minute.

[johnxx9]

They need LSBs because they can switched off and on and provides more specific impulse as you said.

The perfect example is Ariane-4. The basic Ariane 40 model with 2 solid boosters could launch around 2,500 kilograms into Geostationary transfer orbit . The 44L configuration could launch 4,790 kg to the same orbit with four liquid boosters added.

Yes, the problem with GSLV is that the solis stage burns out more quickly than the LSBs and the weight is dragged until the LSBs burn out. Increasing the solid propellant and by using solid fuels with more specific impulse could solve the problem.

[edkyle99]

According to astronautix.com, the original GSLV featured four UDMH/N2O4 liquid boosters strapped onto a solid-propellant first stage:  http://www.astronautix.com/lvs/gslv.htm.

Why the heck would you want liquid strap-ons, with an Isp of 281 s and a thrust-to-weight ratio of 1.6, on a solid core stage with an Isp of 266 s and a ratio of 3.2?

Another weird thing is that the core stage burns out after 93 s, whereas the LRBs burn for 159 s.  So you have to drag the 28 metric tons of the burned-out core stage along for about a minute.

ISRO developed PSLV first, which used the S125 core solid motor augmented by up to six S9 strap on solid motors, topped by an L40 liquid second stage a solid third stage, and a liquid fourth stage.  The agency's approach to create GSLV was to upgrade PSLV by replacing the solid strap-on boosters with L40 liquid strap-on boosters.  The L40 second stage remained, but the upper stages were replaced by a single liquid hydrogen stage.  It was an expedient, not a clean-sheet-ideal, approach.  The L40 strap-on boosters provide roll control, a bit more thrust, and quite a bit more total impulse, than the PSLV boosters.     

GSLV Mark III will be India's "clean sheet" approach. 

 - Ed Kyle

[William Graham]

"Liquid SRBs" is a contradiction in terms

[Proponent]

"Liquid SRBs" is a contradiction in terms

Not if SRB means strap-on rocket booster! 

[William Barton]

What's TO like with solid core, liquid strap-ons?

[isro-watch]

yes, this is the basic problem with a GSLV... the dragging up of core solid stage curtails its launch capability.... ISRO has talked of it....But says it is a design constraint....

In the years to come....ISRO may leave GSLV (and start using only GSLV MKIII version) just like it left ASLV and SLV after PSLV became operational...


There is also talk of increasing the strapons of MKIII from 2 to 4 in future to launch heavier payloads...

even then...both MKIII and GSLV... are fairly complex vehicles unlike ones like ARAINE...

[isro-watch]

ISRO has infact indicated that all problems associated with GSLV will be solved by MKIII version....

let us hope so... a developmental flight is scheduled in 2010....

[johnxx9]

yes, this is the basic problem with a GSLV... the dragging up of core solid stage curtails its launch capability.... ISRO has talked of it....But says it is a design constraint....

In the years to come....ISRO may leave GSLV (and start using only GSLV MKIII version) just like it left ASLV and SLV after PSLV became operational...


There is also talk of increasing the strapons of MKIII from 2 to 4 in future to launch heavier payloads...

even then...both MKIII and GSLV... are fairly complex vehicles unlike ones like ARAINE...

GSLV-Mk III is not as complex as Ariane-5 or any other vehicle.

If observed closely you will see that ISRO uses the largest amount of earth-storable fuels. That has been the main cause for their cheap launch costs and good launch history.

The fact that GSLVMk III will be more close to Titan-III than Ariane-5 will make it more less complex than Ariane-5 which has 2 Cryogenic stages.

[publiusr]

I wonder if structural concerns were behind having the liquids atatch to a more sturdy solid core stage. With the Mk III they evidently feel this is no longer an issue.

[hop]

GSLV-Mk III is not as complex as Ariane-5 or any other vehicle.

Do you have any documentation to support this claim ?

If observed closely you will see that ISRO uses the largest amount of earth-storable fuels. That has been the main cause for their cheap launch costs and good launch history.

Uhm, every one of those statements appears to be incorrect.
- Russia and China use more. Russia launched 10 Protons (all hypergolic with Briz M, or everything but the upper stage with Blok DM) in 2008, plus numerous smaller hypergolic vehicles. All Chinese launchers uses hypergols in the lower stages as well AFAIK.
- Labor costs have more influence than vehicle design, you can see this by looking at Russia.
- What "good launch history" ? ISROs record is not particularly good. See http://www.geocities.com/launchreport/reliability2009.txt
GSLV is 2/5  and PSLV is 12/14

[johnxx9]

GSLV-Mk III is not as complex as Ariane-5 or any other vehicle.

Do you have any documentation to support this claim ?

If observed closely you will see that ISRO uses the largest amount of earth-storable fuels. That has been the main cause for their cheap launch costs and good launch history.

Uhm, every one of those statements appears to be incorrect.
- Russia and China use more. Russia launched 10 Protons (all hypergolic with Briz M, or everything but the upper stage with Blok DM) in 2008, plus numerous smaller hypergolic vehicles. All Chinese launchers uses hypergols in the lower stages as well AFAIK.
- Labor costs have more influence than vehicle design, you can see this by looking at Russia.
- What "good launch history" ? ISROs record is not particularly good. See http://www.geocities.com/launchreport/reliability2009.txt
GSLV is 2/5  and PSLV is 12/14

Ariane-5 uses a cryogenic upper stage and also a cryogenic core stage whereas Mk-III basically has a UDMH/N2O4 core stage. It's common sense that earth storable engines or use of such fuels is comparitively less complex than Cryogenic engines and storage of cryogenic fuels. But the overall design aspects of both the vehicles are same.

Proton uses a Semi-Cryo upper stage and so does many Chinese vehicles. Their CZ-5 is going to be a complete Semi-Cryo vehicle expect for the upper stage which is Cryogenic. I believe even Angara would use Semi-Cryo and Cryo to the max extent.

Anyway Earth storage fuels doesn't only refer to Hydrazine. It also includes solid fuel. We don't see solid boosters on Russian rockets like Proton, Soyuz etc. And also the Chinese, they don't use solid rockets on bigger launchers.

Sorry, but GSLV's launch record is 4 successes and 1 failure. PSLV's record is 12 successes, 1 failure and 1 partial failure. And also we have to take into account that Indian launchers don't fly as often as   
US or Russian launchers.

[Jim]

Anyway Earth storage fuels doesn't only refer to Hydrazine. It also includes solid fuel.

Incorrect, Earth storage fuels DOES only refer to Hydrazine like propellants.  Solids are in a separate category

[Jim]

Proton uses a Semi-Cryo upper stage

He just stated not the Brez version which is the one more in use at this time.  But anyways, the amount of propellant in the first 3 stages is huge compared to the cryogenic Block DM.

You said "ISRO uses the largest amount of earth-storable fuels"   The size of the Proton validates Hop's point that ISRO doesn't use the largest amount

[hesidu]

yes, this is the basic problem with a GSLV... the dragging up of core solid stage curtails its launch capability.... ISRO has talked of it....But says it is a design constraint....

In the years to come....ISRO may leave GSLV (and start using only GSLV MKIII version) just like it left ASLV and SLV after PSLV became operational...


There is also talk of increasing the strapons of MKIII from 2 to 4 in future to launch heavier payloads...

even then...both MKIII and GSLV... are fairly complex vehicles unlike ones like ARAINE...

GSLV-Mk III is not as complex as Ariane-5 or any other vehicle.

If observed closely you will see that ISRO uses the largest amount of earth-storable fuels. That has been the main cause for their cheap launch costs and good launch history.

The fact that GSLVMk III will be more close to Titan-III than Ariane-5 will make it more less complex than Ariane-5 which has 2 Cryogenic stages.

As long as i know, UDMH/N2O4 which used on PSLV and GSLV is more expensive than RP-1/O2, if not more expensive than H2/O2.

[hesidu]

GSLV-Mk III is not as complex as Ariane-5 or any other vehicle.

Do you have any documentation to support this claim ?

If observed closely you will see that ISRO uses the largest amount of earth-storable fuels. That has been the main cause for their cheap launch costs and good launch history.

Uhm, every one of those statements appears to be incorrect.
- Russia and China use more. Russia launched 10 Protons (all hypergolic with Briz M, or everything but the upper stage with Blok DM) in 2008, plus numerous smaller hypergolic vehicles. All Chinese launchers uses hypergols in the lower stages as well AFAIK.
- Labor costs have more influence than vehicle design, you can see this by looking at Russia.
- What "good launch history" ? ISROs record is not particularly good. See http://www.geocities.com/launchreport/reliability2009.txt
GSLV is 2/5  and PSLV is 12/14

Ariane-5 uses a cryogenic upper stage and also a cryogenic core stage whereas Mk-III basically has a UDMH/N2O4 core stage. It's common sense that earth storable engines or use of such fuels is comparitively less complex than Cryogenic engines and storage of cryogenic fuels. But the overall design aspects of both the vehicles are same.

Proton uses a Semi-Cryo upper stage and so does many Chinese vehicles. Their CZ-5 is going to be a complete Semi-Cryo vehicle expect for the upper stage which is Cryogenic. I believe even Angara would use Semi-Cryo and Cryo to the max extent.

Anyway Earth storage fuels doesn't only refer to Hydrazine. It also includes solid fuel. We don't see solid boosters on Russian rockets like Proton, Soyuz etc. And also the Chinese, they don't use solid rockets on bigger launchers.

The third stage of CZ-2E use solid rocket.

[edkyle99]

Sorry, but GSLV's launch record is 4 successes and 1 failure.

There have been three GSLV launch vehicle failures in five attempts. 

On April 18, 2001, the GSLV-D1 third stage shut down 12 seconds early, leaving GSat-1 in a 181 x 32051km x 19.2deg transfer orbit versus the planned 180 x 35975km x 19.2deg orbit.  GSat-1 had insufficient fuel to maneuver to its planned geostationary orbit. 

On July 10, 2006, GSLV-F2  failed to reach orbit after one of its strap-on booster Vikas engines failed two seconds into flight.

On September 2, 2007, GSLV-F4  deposited Insat-4CR into a 168 x 31,786 km x 15.8 deg orbit, well short of its planned 170 x 35,975 km x 21.7 deg orbit.  Insat-4CR was able to reach its planned orbit, but at the cost of life-shortening on-board propellant.   

PSLV's record is 12 successes, 1 failure and 1 partial failure. And also we have to take into account that Indian launchers don't fly as often as   
US or Russian launchers.

The two PSLV failures (in 14 launches) include PSLV-D1, which failed to reach orbit, and PSLV-C1, which left IRS-1D in a 306 x 822km x 98.5deg orbit (versus a planned 817 km circular orbit) after the fourth stage suffered a helium pressurant leak.  IRS-1D could not make up the 130 meter per second delta-v shortfall.  Instead, it used more than 70% of its own propellant to reach a 742 x 822 km "functional" orbit.

In all of the above cases, the launch vehicles suffered some type of hardware or software failure and failed to complete their planned mission assignments, regardless of the final payload disposition.  It is disingenuous, in my opinion, to call these events "successes" or "partial failures".   (Partial failure?  Is that like only having part of my leg cut off?)  A launch vehicle failure is a launch vehicle failure, whether the rocket has flown a thousand times or once.

 - Ed Kyle

[hop]

Ariane-5 uses a cryogenic upper stage and also a cryogenic core stage whereas Mk-III basically has a UDMH/N2O4 core stage. It's common sense that earth storable engines or use of such fuels is comparitively less complex than Cryogenic engines and storage of cryogenic fuels. But the overall design aspects of both the vehicles are same.

Your claim was

GSLV-Mk III is not as complex as Ariane-5 or any other vehicle.

This is a bold claim. For example Atlas V 401 uses only 2 stages with one engine each to get to GTO.

Jim and Ed have addressed the other issues.

I'm not dissing ISRO. They are doing a good job with the resources they have, and historically new organizations have more failures err partial successes.

@ed
I think the "partial failure" terminology makes sense if you are talking about the status of the mission. If your payload gets into orbit, but has reduced service life, then you got part of your mission. If you are talking about the LVs ability to meet it's advertised parameters (as we are here), then it's a failure.

[sanman]

http://timesofindia.indiatimes.com/city/ranchi/Snags-spotted-GSLV-Mark-III-by-mid-2012/articleshow/9396654.cms

[Salo]

Mk III is a mistake in headline.