Indian Space Programme Discussion

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Prasad
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Re: Indian Space Programme Discussion

Post by Prasad »

Folks, I think this should clear your doubts - http://www.isro.org/GroundFacilities/la ... ility.aspx

To think that I had a guided tour to that place ten years back. Can't remember details for $hit but do remember the launch pad and our guide telling us that after every launch everything in the near vicinity is absolutely incinerated.
First Launch Pad
The individual stages of PSLV or GSLV, their subsystems and the spacecraft are prepared and checked out in separate facilities before they are sent to launch pad for integration A-76-meter tall mobile service tower (MST) facilitates the vertical integration of the vehicle. The foldable working platforms of MST provide access to the vehicle at various elevations. A massive launch pedestal, made up of steel plates, acts as the base on which the vehicle is integrated.

The spacecraft is integrated to the vehicle in a clean room, set up inside the MST. However, in the case of GSLV, the spacecraft is interfaced with the payload adopter and then encapsulated in the heat shield in the preparation facility itself. The encapsulated assembly is moved to the launch pad for integrating with the 3rd stage of GSLV. The umbilical tower houses the feed lines for liquid propellants and high-pressure gases, checkout cables, and chilled air duct for supplying cool air to the satellite and equipment bay.

Second Launch Pad
In order to provide redundant facilities for launching the operational PSLVs and GSLVs and also to have quick turn around time for launch, an additional launch pad with associated facilities was constructed. It was designed to accommodate, both the present PSLVs and GSLVs, and also the future launch vehicle configurations such as GSLV-MkIII.
As per the integrate, transfer and launch (ITL) concept, based on which the new launch pad and the associated facilities are designed, the entire vehicle is assembled and checked-out on a mobile pedestal in the Vehicle Assembly Building (VAB) and then moved in vertical position to the launch pad on a roll track.

Other facilities include, Solid Stage Assembly Building (SSAB) connected to the Vehicle Assembly Building (VAB) by a rail track, Technical Complex-2 (TC2), Spacecraft Preparation Facility, Range Instrumentation facilities comprising tracking, telemetry and tele-command systems.
Last edited by Prasad on 08 Jan 2014 09:18, edited 2 times in total.
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Re: Indian Space Programme Discussion

Post by TSJones »

rahulm wrote:I think Falcon uses LOX/Kerosine and not LOX/LH2. Soyuz and Saturn also used this combination. You don't need LOX/LH2 for medium to heavy lift capability to GTO.

There is a school of thought that says ISRO could have realised the GSLV about a decade or so earlier if it had followed the LOX/Kerosine route but instead choose to single mindedly focus on the LOX/LH2 route. There was discussion on BRF about this and Umrao John had plenty to say. May be archived.
Yes, Space X's merlin engines use lox and kerosene. ULA, United Launch Aliance uses the RL10 engine as upper stage engine and it is LOX and LH2. The Saturn upper stage engine J-2 is also cryogenic. The Space Shuttle Main Engine is also cryogenic. So it is a mix of engine types that are available. But Space x is sticking to a Lox and Kerosene. It is developing a new upper stage engine the ra[tor which will be lox and methane.
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Re: Indian Space Programme Discussion

Post by Bade »

So is the conclusion that there are only 2 launch pads now present ?

The first launch pad for PSLV launches has just one VAB which has a mobile design, so it can be pulled out following stacking of the vehicle.

The second launch pad used exclusively for GSLV launches has two VABs as shown in the picture posted by Sridhar. If this is correct how do they get the GSLV assembled in the second VAB behind the other out to the launch pad ? It has to pass through the first VAB. :-)
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Re: Indian Space Programme Discussion

Post by SSridhar »

Bade, firstly, both assembly buildings can assemble GSLVs.

The GSLV built in the second launch pad, which is dubbed as the universal lunch pad, does not move towards the first launch pad, it moves in the opposite direction away from both buildings to the launch tower which is about a Kilometre away.
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Re: Indian Space Programme Discussion

Post by Bade »

But there is only one launch tower a km away as you said from the nearest VAB. I do not see any tracks from the second VAB going out to its own independent launch pad. So there is only one "Universal launch pad", the question remains how to get there from the second VAB. I am assuming two GSLVs can be stacked simultaneously in the two VABs.

I hope I am making myself clear. I did not say that GSLVs assembled in either of the two "fixed location" VABs are moved to the first launch pad. From google maps, the first launch pad facility is independent of the second launch facility ( 2 VABs and a universal launch tower)
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Re: Indian Space Programme Discussion

Post by Comer »

Prasad wrote:*snip*

To think that I had a guided tour to that place ten years back.
Are the guided tours still in operation. Would love to go. Is it extensive enough?
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Re: Indian Space Programme Discussion

Post by Sridhar »

The first launch pad does not have a VAB. It has what is called a Mobile Service Tower - a metallic structure on wheels with multiple platforms to assemble and service the vehicle prior to launch. Bfire the launch, the MST is moved away from the launch pad

The second launch pad had only one VAB when the launch pad was built. The vehicle is assembled in the VAB and then moved to the launch pad a few days before launch for final checkout and fuel loading operations. This configuration was planned all along with the idea that more than one VAB would be built, expanding the launch pad's capacity. If a vehicle takes 2 months from the start of assembly to launch and it takes only a month from the time the vehicle is moved to the pad until the end of cleanup operations on the pad, one VAB provides for a maximum of 6 launches a year, whereas two VAB's allow for 12 launches, which is the capacity of the pad itself. ISRO got sanction for this second VAB for the second launch pad last year.

The third launch pad project is independent of this.

So Prasad: if I understand you correctly, what you are saying is that the building in the background is the solid stage assembly building and not a VAB at all. That would answer my question.
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Re: Indian Space Programme Discussion

Post by Bade »

Aha..so it is a assembly line of sorts. The bldg in the background does the solid stage assembly and then it is moved to the VAB for the final stage assembly before pushing towards the launch tower. This can increase efficiency as it frees the first bldg facilities to prepare for the next launch.
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Re: Indian Space Programme Discussion

Post by symontk »

As I had mentioned earlier, the one in the photo background is first launch pad and is not at all connected to VAB (second launch pad) where GSLV is shown standing. But of course there are same facilities for Solid stage integration, liquid / cryo fuel storage at the site which is used by both VAB / MST

There is also an unused ASLV VAB. Interestingly here the launch vehicle is integrated and moved out for the launch to the pedestal unlike the first launch pad where the MST rolls back after the integration. ASLV tower is almost close to the SLV-3 launch pad

The second launch pad is now primarily used for GSLV launches and will also be used for GSLV Mk3 too. There can be more VAB's associated with the second launch pad that will be added in due course
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Re: Indian Space Programme Discussion

Post by SSridhar »

Bade wrote:But there is only one launch tower a km away as you said from the nearest VAB. I do not see any tracks from the second VAB going out to its own independent launch pad. So there is only one "Universal launch pad", the question remains how to get there from the second VAB.
Let us distiinguish between vehicle assembly buildings and launch pads. The vehicle is assembled in the former and launched from the latter. The older vehicle assembly building (aka MST) is an integrated assembly cum launcher. That is why it is called Integration on Pad (IOP). The MST is then moved a few hundred metres away and the launch is done. So, one may not find a lengthy track to move the MST.

The second has a VAB and a separate launch pad. Hence the long track from the VAB to the launch pad.

PS: Pictures of a PSLV in the first launch pad and GSLV-D05 on the second launch pad would clearly show the difference between these two launch pad designs.
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Re: Indian Space Programme Discussion

Post by Sridhar »

Symontk: The building in the background is most definitely not the MST of the first launch pad.

Bade: the solid stage is also assembled in the VAB as far as I know. The GSLV has five solid segments which are assembled in the VAB to form the first stage. I am not sure what the solid stage assembly building in Prasad's post is all about.
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Re: Indian Space Programme Discussion

Post by Sridhar »

For reference, this is what the mobile service tower of the first launch pad looks like.

Image


Also, the location of the first launch pad is to the north of the second launch pad, while the VAB (and this other building which I was asking about) lies approximately SW with respect to the second launch pad.

Looking at the google maps satellite view of SHAR, it seems like Prasad's explanation is the correct one. It is not a VAB at all (what threw me off was the facade of the building, which looks very similar to the VAB, with its big sliding doors on the front of the building. But from the satellite image, it seems like a building that services the existing VAB, with tracks running to it. A second VAB would need to have tracks running to the launch pad, not to the first VAB.

The second VAB has just been sanctioned last year, and I am guessing it will take at least a couple of years to be commissioned. Until then, the capacity provided by the first and second launch pads should be sufficient. Both the existing launch vehicles can be launched from either pad. Between them, they provide a theoretical capacity of approx. 12 launches a year (less in practice because of the monsoons), which is sufficient for now. The second VAB will allow ISRO to ramp up capacity, and this will be particularly important once the GSLV MK3 crosses its development phase. That is still several years away. The third launch pad is still in the proposal stage, and will provide necessary launch infrastructure for human spaceflight, as well as the next generation of launchers.
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Re: Indian Space Programme Discussion

Post by Sridhar »

It turns out that this is indeed the solid stage assembly building, which is a new facility built for the GSLV-MK3 program. The PSLV, GSLV-MK1 and MK2 are completely assembled in the VAB. But the MK3 involves assembly of the S-200 solid boosters in the solid stage assembly building.
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Re: Indian Space Programme Discussion

Post by SSridhar »

^ yes, that is what it is. From the SHAR website,
Other facilities include, Solid Stage Assembly Building (SSAB) connected to the Vehicle Assembly Building (VAB) by a rail track . . .
Apparently, the segments of the two solid booster S200 motors and the core liquid L110 stage are integrated here and then sent to VAB for further integration with the upper stage and payload.
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Re: Indian Space Programme Discussion

Post by Sridhar »

Also, Bade, the launch pedestal with two 'holes' in it in the satellite image is likely the launch pedestal for the GSLV-MK3, with its two S-200 solid boosters. The old launch pedestal would likely not work for the MK3, with its exhaust vent designed for the PSLV and GSLV (both have the same S-139 core solid stage, with 4-6 smaller boosters.

Added: The google satellite image also shows the old PSLV/GSLV mobile launch pedestal, with its single exhaust vent. It is parked on tracks perpendicular to the ones leading from the solid stage assembly building to the vehicle assembly building. In fact, it appears that there is a set of tracks to bypass the VAB. Perhaps because the same solid stage assembly building will service the second VAB once it is built.
Last edited by Sridhar on 08 Jan 2014 12:23, edited 1 time in total.
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Re: Indian Space Programme Discussion

Post by vina »

There surely is something to be said for the liquid engine stuff. It is less of a safety hazard than a couple of giant solid stages being put together. You keep the liquid stuff safe in storage and pump it in just before launch. Not possible with solids, where a stray spark, static discharge or some such accident can set off a big disaster (Brazil Alacnatera siteand their VLS accident comes to mind).

The other advantage with an all liquid stuff is that you can integrate the entire rocket horizontally like the Soviets/Russians , roll it on to the launch pad, erect it and launch. Not possible with large solid stages (the SLV3 is about the max you can get with solid stages integrated horizontally and brought vertical and launched).
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Re: Indian Space Programme Discussion

Post by SSridhar »

Sridhar wrote:Also, Bade, the launch pedestal with two 'holes' in it in the satellite image is likely the launch pedestal for the GSLV-MK3
Quite likely. The SHAR annual report for 2011 says that the pedestal for Mk III had been realized.
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Re: Indian Space Programme Discussion

Post by Arunkumar »

Success of GSLV seems have applied mirchi on the backside of someone in langley.

http://timesofindia.indiatimes.com/indi ... 534030.cms

Hit job on Vikram sarabhai by digging out details about his personal life.
I find psychiatrists tend to attribute sexual motives to very action in life!"
Lot of similarity with nambi's case where he was portrayed to be craving for sekz.
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Re: Indian Space Programme Discussion

Post by SSridhar »

vina, another problem with the solid motors is that they may develop minute cracks in the process of moving, lifting etc and these could be disastrous for the flight.
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Re: Indian Space Programme Discussion

Post by Prasad »

saravana wrote:
Prasad wrote:*snip*

To think that I had a guided tour to that place ten years back.
Are the guided tours still in operation. Would love to go. Is it extensive enough?
Visited during yingineering days saar as part of a visit. Don't think they let private citizens in. Did manage to talk about the SLR that a CISF-wala was carrying during lunch :)
Sridhar wrote:So Prasad: if I understand you correctly, what you are saying is that the building in the background is the solid stage assembly building and not a VAB at all. That would answer my question.
Yes. That is, if i'm not wrong, where the solid stages (S200?) are assembled. The separate launch pad that doesn't have a VAB is the older one that was used for SLV3/ASLV launches.
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Re: Indian Space Programme Discussion

Post by Sridhar »

Vina/SSridhar,

The under-development semi-cryo engine will address some of these issues. Unlike the UDMH/N2O4 fueled liquid stages it currently has, with their handling related issues and limits on scaling up, the new 2MN semi-cryo will eliminate ISRO's current dependence on solids for high thrust first stage motors. The ULV family of launchers will likely have a clustered semi-cryo first stage, and cryo upper stage, with solids and hypergolic liquid engines employed only in boosters.

There is a history behind the ISRO investment in solids (simple, easier to master with limited human resources and technical infrastructure) and UDMH/N2O4 liquid engines (technology transfer from the French to overcome human resource and other technical limitations + spillovers for engines for satellites). There was an opportunity to invest in semi-cryos and cryos in the 80s and 90s, but that is the past. Now, ISRO is investing in the full range range of propulsion technologies, and also more a family of launchers with more sensible configurations.
Last edited by Sridhar on 08 Jan 2014 12:51, edited 1 time in total.
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Re: Indian Space Programme Discussion

Post by Sridhar »

Prasad wrote:
Sridhar wrote:So Prasad: if I understand you correctly, what you are saying is that the building in the background is the solid stage assembly building and not a VAB at all. That would answer my question.
Yes. That is, if i'm not wrong, where the solid stages (S200?) are assembled. The separate launch pad that doesn't have a VAB is the older one that was used for SLV3/ASLV launches.
Thanks - that is what I found out as well. BTW, the SLV3/ASLV launch pads are defunct. The first launch pad (the one with the mobile service tower) is mostly used for the PSLV now, though it can support GSLV-MK1/2 launches as well (and the first GSLV-MK1 was indeed launched from that pad).

The nomenclature is confusing, since the first launch pad was not the first one to be built at SHAR. But that is the nomenclature that ISRO uses, hence I am using the same.
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Re: Indian Space Programme Discussion

Post by SSridhar »

I am not saying that we discard solid motors. In fact, we have now developed an enviable mastery in this area and solid motors have their advantages as well. I am simply pointing to the problems in them. After they are cast, cured and inspected, they must be handled with extreme care.
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Re: Indian Space Programme Discussion

Post by venkat_r »

Sridhar sir, I thought that solid motor was simple and easier to maintain than the liquid ones - My knowledge stems from the reusable components of the solid boosters of space shuttle or uncle had probably the technology for making them so. I believe new Indian versions are also being planned to be reused which would mean that they are probably more rugged.

Space shuttle boosters
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Re: Indian Space Programme Discussion

Post by vina »

Sridhar sir, I thought that solid motor was simple and easier to maintain than the liquid ones - My knowledge stems from the reusable components of the solid boosters of space shuttle or uncle had probably the technology for making them so. I believe new Indian versions are also being planned to be reused which would mean that they are probably more rugged.
A solid rocket is exactly like your diwali rocket.And after it is used, all that is left is the shell ! So not much is getting "reused" in the first place, other than the shell and the nozzle (approx some 90 tons of steel in total!) :P . Much of the weight is propellants that went poof!

In fact, with the shuttle, the main proposals for reuse were the Shuttle Booster Fly Back Proposals, which used an oxygen rich staged combustion cycle (the US by then had got to know what the Russians had accomplished) and the fact that the oxygen rich cycle, since it left no soot and residues, could be reused without too much effort ! The US style fuel rich cycle, left so much gunk and residues and stuff, that removing all of it for reuse was impossible.So really if you have a liquid engine that is re useable, you could just top it back up with fuel and lox and you are good to go!

That brings us to the point of LCH4 cycle. LCH4 , in addition to higher Isp than Kerosene leaves no gunk behind!.
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Re: Indian Space Programme Discussion

Post by putnanja »

What about composite motor casing for solid motors like what they have for Agni missiles? Won't that reduce the weight and increase payload?
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Re: Indian Space Programme Discussion

Post by Sridhar »

Yes, that would increase the payload capacity. That said, given that ISRO is building the MK3 in the near future as well as a new generation of launchers within the next decade or so, anything more than tweaks to the GSLV-MK2 design is unlikely due to cost/benefit calculations. Like in the case of the PSLV, these relatively minor modifications (the biggest one being larger booster motors) will substantially increase the payload - the PSLV started at 900 kg to sun synchronous orbit, and can now place 1.5T in geo transfer orbit. Similarly, the GSLV-D5 has now placed an under 2T payload in GTO (the stated goal of the GSLV program when it was initiated), but can probably go up to 2.5T or beyond. Anything over that will be taken up by the MK3.
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Re: Indian Space Programme Discussion

Post by Sridhar »

Here's a labeled screenshot of the VAB and associated facilities.

Legend:
SSAB = Solid Stage Assembly Building (for GSLV-MK3)
VAB = Vehicle Assembly Building
MLP = Mobile Launch Pedestal (on which the vehicle is assembled, and then moved to the launch pad before launch)

Image

You can clearly see the MLP for GSLV-MK3 with two exhaust vents for the two S-200 solid boosters, and the MLP for the PSLV and GSLV MK1/2, with a single exhaust vent for the S-138 solid core stage.

There is also a location where the tracks end abruptly. It could be the location for the second VAB which has been approved - this is purely an educated guess on my part. It seems to make sense that it would be where the second VAB would be located, since it would justify the new tracks bypassing the existing VAB. The bypass tracks would be used to move the solid stages from the SSAB to the second VAB.

As an interesting aside, it appears that the mobile launch pedestal has two sets of wheels perpendicular to each other, with some mechanism to lift and lower one set of wheels at a time. That must be how they accomplish the 90 degree turns in the tracks. i.e. the MLP is wheeled to the end of the 90 degree turn. Then the perpendicular wheels are lowered and the set of wheels used before are raised. This must be done at every place with a 90 degree turn. Or are there other ways to accomplish the turn?

The satellite image is from Bing, which is clearer than the Google maps image. Also, note that this map is rotated by about 180 degrees, i.e. North is approximately at 6 o'clock in this map rather than the usual 12 o'clock.
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Re: Indian Space Programme Discussion

Post by Vipul »

India's human space flight programme is at the beginning: Radhakrishnan.

Even as the country is rejoicing over the successful launch of the Mars Orbiter Mission in November, 2013, ISRO Chairman K Radhakrishnan said Wednesday that Indian human space flight programme is at the “beginning stage”.

He also said that space scientists were studying the critical technologies required for the project.

“As far as human space flight is concerned, we are just at the beginning- at the moment we are studying the critical technologies required for that like- crew escape system, crew module... These are the things we have not done in the past,” Radhakrishnan said.

“As and when we take up a programme of human space flight- this will help us,” he said while speaking to reporters in the presence of Parliamentary Standing Committee on Science & Technology, Environment and Forest that reviewed ISRO programmes here.

Illustrating the requirements for the human space flight, he said “we need a reliable launch vehicle with a reliability of 0.99, today we can say GSLV has gone well- but we need to improve the reliability of that.”

“We also need to have a capacity for taking crew module with two or three crew members and the required space for them; so we have the choice of GSLV or GSLV Mark III- that is the decision we need to take.”

While space robotics and human presence in space together are certainly going to be the requirements for the future, he also said “at a right moment -that decision- the country will have to take.”

“What we are doing at the moment is getting ready for critical technology and government has given us funds nearly Rs 145 crore.”

He said “in the GSLV Mark III- the experimental mission is going to happen in April 2014....”

Parliamentary Standing Committee Chairman T Subbarami Reddy while talking to reporters after the review praised the recent achievements of ISRO for the successful launch of Mars Orbit Mission and GSLV-D5 with indigenous cryogenic engine.

Stating that adequate funds are being allocated for the scientific sector in the country, he said “we must focus more towards developing good scientists.”

He said young people should be encouraged towards science and scientists should be given special salaries, special incentives, and special encouragements. His committee is recommending the same, Reddy added.
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Re: Indian Space Programme Discussion

Post by Sridhar »

A followup to my previous post. It turns out that the location of the second VAB is not where I guessed it would be (based on track layout and configuration). The site plan is in the annual report of the Satish Dhawan Space Center, though the quality of the image is quite poor.

Image

In this schematic, the second launch pad is at the bottom right (with the four purple colored lightning towers clearly indicating the launch pad). The current VAB and SSAB are on straight tracks leading approx NW from the second launch pad.

The second VAB is approx near the center of the image, with the proposed third launch pad at about the center left of the image. This second vehicle assembly building will have tracks leading to both the second and third launch pads. Also, with the track configuration, a vehicle assembled in the existing VAB can be transported to the third launch pad as well. It seems like the first launch pad, with its mobile service tower will be a standalone one.

Here's a link to the SDSC annual report.

http://www.shar.gov.in/sdsc/sites/defau ... t_2013.pdf
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Re: Indian Space Programme Discussion

Post by Bade »

Sridhar, thanks for all the links and imagery. It all makes perfect sense now.

As for human space flight, I do not think it will happen before at least 10 successful consecutive launches of GSLV. If we have enough transponder requirements and an assembly like of GSATs we could get there fast enough.
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Re: Indian Space Programme Discussion

Post by PratikDas »

Confirming the above, from the tender for Technical Services For Second Vehicle Assembly Building (SVAB) And Associated Systems (lots of great technical drawings in this)

Image
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Re: Indian Space Programme Discussion

Post by SSridhar »

How ISRO developed the indigenous cryogenic engine - Economic Times
The year was 1987. V Gnanagandhi, head of the cryogenic engine project at the Indian Space Research Organisation (ISRO), wanted to set up a high-pressure hydrogen plant in Mahendragiri near Thiruvanathapuram. But an official from the supplier of the machinery, a German company called Messers Grieshem, suddenly threw a spanner in the works. "There are snakes and elephants on the roads in India," he told them. "How can I come there?"
When it flew, the GSLV put the satellite into orbit with a precision never possible with the Russian engines
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Re: Indian Space Programme Discussion

Post by Varoon Shekhar »

^
My cousin in India runs a small scale unit which exports a consignment to Germany. When there were floods in India, the production and export were affected, but the Germans were upset about the delays. Then, Germany itself experienced major flooding, causing all kinds of delays of production and export. So the German party finally understood.

Germans and Swedes are generally not sophisticated and empathetic when it comes to India. They will play up the negative- disasters, diseases, violence, social conditions like child labour, women's rights et al. And snakes and elephants. Subtlety and nuance are not their cup of tea! I'm sure there are exceptions.

Edited: There was actually a German official who spoke very highly about India's space programme several years ago. And the audio feature appeared on BBC's website. It is no longer there. Did anyone retrieve it?
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Re: Indian Space Programme Discussion

Post by Sagar G »

putnanja wrote:What about composite motor casing for solid motors like what they have for Agni missiles? Won't that reduce the weight and increase payload?
Making a composite structure that large isn't easy and add to that the tolerances expected, the mold making will be a pain in the musharraf. We are yet to make Agni 5 an all composite missile lest people have forgotten.
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Re: Indian Space Programme Discussion

Post by Sridhar »

The tracks around the VAB also make sense now since I remembered that the doors on the other side of the VAB (the one facing the SSAB) are not high enough for the assembled S200 boosters to pass through. Hence the assembled S200 boosters on the MLP will be wheeled around the VAB and brought inside through the doors that the finally assembled launcher is wheeled out on.
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Re: Indian Space Programme Discussion

Post by member_28041 »

Sridhar wrote:Vina/SSridhar,

The under-development semi-cryo engine will address some of these issues. Unlike the UDMH/N2O4 fueled liquid stages it currently has, with their handling related issues and limits on scaling up, the new 2MN semi-cryo will eliminate ISRO's current dependence on solids for high thrust first stage motors. The ULV family of launchers will likely have a clustered semi-cryo first stage, and cryo upper stage, with solids and hypergolic liquid engines employed only in boosters.

There is a history behind the ISRO investment in solids (simple, easier to master with limited human resources and technical infrastructure) and UDMH/N2O4 liquid engines (technology transfer from the French to overcome human resource and other technical limitations + spillovers for engines for satellites). There was an opportunity to invest in semi-cryos and cryos in the 80s and 90s, but that is the past. Now, ISRO is investing in the full range range of propulsion technologies, and also more a family of launchers with more sensible configurations.

Not able to get the payload advantage of ULV(with 2MN semi-cryo) over the MK3.

The first stage specs of MK3 is as follows :
2 Solid boosters, 5MN each. Total : 10MN
Twin vikas engine liquid stage : 1.6MN
Total Thrust: 11.6 MN

Now the planned ULV:

Single 2MN core stage : 2MN
4*2MN boosters : 8MN
Total Thrust : 10MN(I am not sure if this is the planned configuration of ULV)

Hence is it not the case that the planned ULV will have lesser thrust from the booster and first stage compared to the MK3?
Please correct me if i am wrong here.
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Re: Indian Space Programme Discussion

Post by member_28348 »

Image
:eek: a beautiful launch sequence...love those "arms" set off the rocket like a person. 8)
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Re: Indian Space Programme Discussion

Post by member_23694 »

nitinraj wrote:Now the planned ULV:

Single 2MN core stage : 2MN
4*2MN boosters : 8MN
Total Thrust : 10MN(I am not sure if this is the planned configuration of ULV)
slight modification

basic configuration could be
1 -SC core
2 S-200 Strap-on
1 -C-25 and probably future higher thrust cryos

other combinations could also be possible
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Re: Indian Space Programme Discussion

Post by disha »

unable to reproduce the full article from ET, see the following snippet:

If flying the Russian engines was hard, copying the engine design was harder. The Russians had designed these engines in the 1960s but not flown them, probably because they were still not flight ready. Moreover, they used a technology— called stage combustion—that was efficient but difficult. It made the engine a bit heavy but gave the highest efficiencies for a specific amount of propellant. The indigenous engines had to be exactly like the Russian engines: the GSLV has already been planned based on them.

...

"We became failure-hardened," says Mohammed Mulsim, head of the cryogenic project at that time. "After each failure we went back not to the Russian engines but to the drawing board." They succeeded finally in 2002. The indigenous cryogenic engine was qualified in 2003. It took another four years to integrate it with the GSLV. But the first flight failed in 2010, as the engine shut down three seconds after ignition.

...

When it flew, the GSLV put the satellite into orbit with a precision never possible with the Russian engines.


Read more at:
http://economictimes.indiatimes.com/art ... aign=cppst
Note with GSLV-D5, the cryostage gave 7.5KN to 8.2KN and back to 7.5KN. Basically it throttled up by some 10% and throttled back down. It effortlessly put the sat in orbit.

So what are the implications?

1. India is the second country to have its *own* working Staged-combustion technology. If at all we have to measure in terms of gens, particularly if efficiency is next-gen, then India has mastered a next-gen technology.

2. US in its Atlas series uses RD-180 Russian engines., and is able to replace 5 of its engines with 1 of RD-180.

I think India should work on the staged-combustion technology further and scale it up. If CE 7.5 morphs into CE 75, that will be great!
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