GSLV-Mk III launch program/post-launch analysis

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Re: GSLV-Mk III launch program/post-launch analysis

Postby disha » 09 Jun 2017 12:43

Singha wrote:can upper stage cryo stacking give benefits like a 2nd stage CE20 topped by a 3rd stage CE7.5 ? .... or the game is over and done with in the 1st stage power rating?


You will have to increase the lower stage thrust. You still have to carry the upper stage out of atmosphere. So yes the game is over and done with in the 1st stage power rating.

rahulm wrote:In addition to the CE20/25 gas generator engine and stage respectively, CE 7.5 staged combustion engine we also have mastered liquid engine clustering. These 3 are building blocks.


And monster solid stage boosters. The two S-200 are massive., real thunder thighs of Mk3! Rambha has a competition in Urvashi I think :-D

SpaceX's stage recovery is impressive. Nice shock and awe.

ISRO has sweated blood and guts last 50 odd years. Next ten years and onwards are rewards unless a disruptive tech comes along.


RLV & TSTO in launch., iON thrusters/Solar arrays/foldable antennas/lithium batteries on satellites.

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Re: GSLV-Mk III launch program/post-launch analysis

Postby Singha » 09 Jun 2017 14:26

The paul allen rutan combo thing bears watching esp for polar orbit medium sats. The launch pland has rolled out. It looks like the space tourist mothership concept that rutan already used.

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Re: GSLV-Mk III launch program/post-launch analysis

Postby prasannasimha » 09 Jun 2017 17:31

LOX H2 Density: 0.28 g/cc
HTPB 1-2 g/cc

SRB's have a high propellant density a. no need ofcomplex plumbing etc and earth storable while having a lower specific impulse. For a given volume though they provide a very high thrust which is useful in the dense atmosphere and works out to be cheaper "off the shelf"(storable) and less complex albeit at the cost of less specific impulse. it is all atrade off between one for the other and not so ismple. Ideally a full cryogenic set up would be ideal but will be costly and complex so even the space shuttle sued these boosters to simplify certain things.

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Re: GSLV-Mk III launch program/post-launch analysis

Postby Varoon Shekhar » 09 Jun 2017 18:39

Prasanna, Disha et al, could we please have some analysis of the current perigee-apogee issue with the GSAT-19? There is some concern among space afficionados that there was a 'shortfall with respect to the perigee of the satellite, caused by complications created by a possible over performance of the C-25 stage. On the Nasa Space Flight forum, it is the major subject going on now. What are the worst and best case scenarios here? What would cause the evident anomaly in the first place?

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Re: GSLV-Mk III launch program/post-launch analysis

Postby Neela » 09 Jun 2017 18:53

Talking past each other.
When there was a huge market for satellite launches only US/Europe/Rus had the capability to launch them. They realized that they needed to pack more to GTO to launch multiple satellites and developed the Soyuzes, Deltas and the Arianes. It was a limited launch capacity market and they made full use of it. This in turn funded further development.

But the argument that "competing with established players on payload capacity" is not a right approach/not a differentiating factor does not factor in the growing number of countries getting in the build-satellite-and-outsource-launch model. Indonesia,Egypt,Nigeria,Malaysia,Singapore all of are slowly getting into it.
Throw in political influence,friendly relations and you can corner a piece of the pie. Especially with waning influences by established players.

Thankfully, ISRO is throwing the hat into the ring.

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Re: GSLV-Mk III launch program/post-launch analysis

Postby JTull » 09 Jun 2017 19:13

Apologies, if posted here earlier

ISRO: How calculated risks have translated into more frequent and sophisticated launches

Employees at the Indian Space Research Organisation (Isro) do not open champagne bottles to celebrate success. As soon as a rocket launch is over, they go back to their offices and start working on the next launch. About two years ago, Isro decided that this practice was not good enough. No, they weren’t yearning for the bubbly. Rather, the organisation was keen to begin assembling the next rocket well before a specific launch was over. So, it created teams and processes to that end.

The successful launch of the Geostationary Launch Vehicle (GSLV) Mark III on Monday was a major milestone in Isro’s five-decade history. A similar success would have resulted in celebrations in some space agencies around the world. But, on Tuesday morning, employees at the Satish Dhawan Space Centre (Shar) in Sriharikota were back to working on the half-assembled Polar Satellite Launch Vehicle (PSLV) C-39, which will soon be assembled fully and launched on June 23. used to concentrate on one mission,” says director P Kunhikrishnan. “Now we work in parallel to increase the throughput.”

By the end of this month, Isro would have made four rocket launches this year itself. Two of them were technically challenging, one being GSLV Mark III and the other the launch of 104 satellites on one rocket. By the month-end, Isro would also have built four satellites this year. They include the Gsat-19, a sophisticated satellite with high throughput that is expected to improve communication significantly in the country. It was put into orbit on Monday by the GSLV Mark III.

Even a casual observer would have noticed that the frequency of Isro’s missions has been increasing in recent times. Isro is also tackling missions of increasing sophistication, and slowly reducing the gap between India and the other space powers. Early next year, Isro will launch its second lunar mission, consisting of an orbiter, lander and rover.

If the government gives its approval, Isro will also begin work on a human mission sometime soon. With two different rockets and a third to be available soon, Isro will have an increasing presence in the global commercial market. When current chairman Kiran Kumar took over two and a half years ago, Isro was in good shape from a technical perspective.

The Mars mission had been accomplished and the GSLV, a thorn in Isro’s flesh for a long time, had been successfully flown. A cryogenic engine had been developed, and a human crew capsule tested by atmospheric re-entry. Through all these, the PSLV had been launching satellites with exquisite precision.

This was not always the case, as Isro went through a difficult phase about seven years ago. A GSLV launch failed and a cryogenic engine shut off prematurely. Another mission was aborted due to a fuel leak. “When you encounter difficulties,” says Kiran Kumar, “the concentration of the people goes towards solving those problems. But, once these problems are solved, the concentration is on how we can make things happen at a faster pace.”

The technical problems had delayed Isro’s programmes significantly. The GSLV should have been ready by 2009, but its first successful flight was only in 2014. The cryogenic engine should have been ready early in the millennium, but it was successfully flown only in 2014. Even the PSLV had a backlog. The government was aware of the problems, but continued to support the organization.

Soon after he took over, Kumar reengineered Isro to work faster. The senior management sat down and identified the bottlenecks. They strengthened the technical review system. They also optimized procurement and methods of testing. Separate divisions were created to deal with operations and R&D.

Projects were done in parallel. “The chairman asked us to push ourselves to the limit,” says S Somanath, director of the Liquid Propulsion Systems Centre (LPSC) in Thiruvananthapuram. The results were evident soon. The launches increased in frequency.

The backlog of satellites and launches has decreased, but national requirements are so large that Isro will be kept busy for a long time. The commercial opportunities are also not insignificant. “There is a shortage of launchers, whether it is higher capacity of lower capacity,” says Kumar. Isro, especially in the current high-speed environment, has the ability to respond quickly to market needs.

With PSLV launches increasing in frequency, satellite builders get opportunities for launch with low turnaround time. Isro’s launch costs also go down. None of these would have been possible if the technical problems had been left unsolved. In its nine-year history, GSLV Mark I and II together had notched five failures till December 2010. After Mark I failed in December 2010, Isro took two years before trying the next launch. In August 2013, GSLV Mark II flight was aborted due to a fuel leak. These failures delayed GSLV Mark III as well, as its facilities were used for Mark II for some time.

Isro subsequently did such thorough analysis of the GSLV that some of its engineers had said that they would not have known what to do if it had failed again in 2014. Its successful flight in January 2014 was a major turnaround for Isro. The preceding years were the period when Isro engineers mastered several technology areas, including the cryogenic engine, and developed confidence to take more risks. It also grabbed world attention through the mars mission. “Two successful GSLV launches showed that whatever we worked out was successful,” says Kumar. “Technology is no longer an issue.” He could look at more challenging problems from 2015 onwards.

Isro now became very serious about adhering to the fixed launch date. Launch dates became sacrosanct. Only a newly-formed project management council had the right to change a launch date, and that too when done well in advance. Once Isro became serious about not changing the launch date, work culture changed for the better. People picked up speed. “In the aerospace sector, there is a belief that we should not hurry,” says Somanath. “But we can do faster. By doing things faster, nothing bad is going to happen.”

Isro then looked at its testing methods and decided to optimise them. Launch vehicle components were being tested in Thiruvanathapuram, transported to the launch centre at Sriharikota and then tested again. Isro decided to test them only at Sriharikota, thereby saving time. “We took a calculated risk,” says K Sivan, director of the Vikram Sarabhai Space Centre in Thiruvananthapuram.

If the components were found to be faulty during tests at Shar, Isro would have lost more time. However, engineers at VSSC by now have the confidence in their skills to take this risk. The biggest changes were reserved for Shar, which got big investments to create new facilities. Shar also started activities in parallel. It had built a solid stage assembly building, exclusively meant for GSLV Mark III.

This rocket had big solid motors – the third largest in the world – that could not be made by industry, and needed these special facilities for assembly. Isro also decided that the assembly building would be used for PSLV assembly as well. When the solid stage assembly building was being used for multiple vehicles, two vehicles could be assembled in parallel. Earlier the practice was to launch a rocket, clean up and repair the launch pad in about three weeks, and then start the new assembly. Now vehicles are assembled in parallel without affecting each other. Shar is building a third vehicle assembly bay that will be ready by the end of the year, and it will increase the efficiency even more.

Isro has two launch pads. From the first pad, it can launch six PSLVs. When the third assembly bay is ready, the throughput from the second launch pad will increase to ten, or probably 12 when teams are stretched fully. It means that Isro can have 18 launches from next year onwards.

Its launch capacity will remain at this level till it builds a third launch pad. Isro now has an extremely reliable vehicle in PSLV, which is being used by many satellite builders for launch. GSLV Mark II is now operational, and so Isro has a second vehicle for commercial launches. GSLV Mark III will be declared operational after one more flight, scheduled to happen after a year. It can launch satellites of up to 4,000 kg in weight.

As Isro developed more powerful launch vehicles, the weight of communication satellites kept going up. However, electric propulsion in satellites is promising to bring down their weight in the near future. So the GSLV Mark III will enter a lucrative commercial market soon. Big rockets are not optimized to launch 4-5-tonne satellites.

Arianspace, whose Ariane 5 rocket can launch payloads of more than ten tonnes, is now developing Ariane 6 for launching satellites of around five tonnes. So the two GSLV vehicles are addressing a market that may not go away soon. “I am confident that the GSLV Mark III will have a long life,” says K Radhakrishnan, former chairman of Isro.

Over the next few years, Isro is planning to start a joint venture with private industry to launch vehicles and make satellites. Isro itself is going to concentrate on future challenges, leaving the routine jobs to the joint venture. This entity is expected to start work by 2021. Isro’s biggest challenge after that will be to take humans to space.

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Re: GSLV-Mk III launch program/post-launch analysis

Postby disha » 09 Jun 2017 19:24

Varoonji- in quick passing., current perigee & apogee does not matter much. It is the orbit inclination which is important.

First two are development flights for a good reason., they are to coalesce around calculated vs actual performance values

Added later: GSLV-MK III inserted into a near perfect orbital inclination. The goal was 170 x 35,975 km., 21.5 deg inclination., and it was reportedly tracked to 163 x 34,592 km., 21.5 deg inclination.

Remember., changing the orbital inclination is tougher than compensating for any minuscule short fall in perigee. The perigee difference is so small that Maruti 800 traveling at 60 km per hour can tug and drag the satellite into brochure number GTO :-).

Orbital inclination is very precise., actually extremely precise and that is what matters in this particular case.
Last edited by disha on 09 Jun 2017 21:45, edited 2 times in total.

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Re: GSLV-Mk III launch program/post-launch analysis

Postby prasannasimha » 09 Jun 2017 20:07

LAM firing will correct it.
There may hve been subtle changes in flight parametes due to change in the shape of the solid rocket boosters nose cones and also covering the open truss. If you go through the altitude-time flight curve of the first CARE experiment there was a slight issue wrt the trajectorywhich was self corected by the onboard computer. This may have been attributed to these issues and seem to have been corrected so since this is a developmental flight there would be calbration by using the data that has been obtained. The best of simulations will still pale before the actual flight data.
As far as the perigee and apogee difference - not much of an issue because that will be easily corrected . As Disha mentioned the major energy usage in any orbital correction maneuver is in inclination change- that is the one that will use the most fuel.That has been precise

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Re: GSLV-Mk III launch program/post-launch analysis

Postby SSridhar » 09 Jun 2017 20:41

A difference with this flight from the earlier ones is the deployment of the solar panels. They are not deployed immediately after launch. They seem to be deployed only after LAM firings are over. The Li ion battery must be taking care of power until then.

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Re: GSLV-Mk III launch program/post-launch analysis

Postby ArjunPandit » 09 Jun 2017 20:54

SSridhar wrote:A difference with this flight from the earlier ones is the deployment of the solar panels. They are not deployed immediately after launch. They seem to be deployed only after LAM firings are over. The Li ion battery must be taking care of power until then.

Does it make deployment easier?

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Re: GSLV-Mk III launch program/post-launch analysis

Postby Varoon Shekhar » 09 Jun 2017 22:02

Thanks guys, that's good to know. I suppose the concern now, is that the extra LAM firing to correct the perigee, might shorten the lifespan of the satellite. Certainly, that's a concern expressed on the NASA forum.

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Re: GSLV-Mk III launch program/post-launch analysis

Postby prasannasimha » 09 Jun 2017 22:08

Station house keeping will consume propellant. Of course some fuel will be used for LAM firings but this will all be factored in.

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Re: GSLV-Mk III launch program/post-launch analysis

Postby ramana » 09 Jun 2017 22:20

My comments...
Apologies, if posted here earlier

ISRO: How calculated risks have translated into more frequent and sophisticated launches

Employees at the Indian Space Research Organisation (Isro) do not open champagne bottles to celebrate success. As soon as a rocket launch is over, they go back to their offices and start working on the next launch. About two years ago, Isro decided that this practice was not good enough. No, they weren’t yearning for the bubbly. Rather, the organisation was keen to begin assembling the next rocket well before a specific launch was over. So, it created teams and processes to that end.

The successful launch of the Geostationary Launch Vehicle (GSLV) Mark III on Monday was a major milestone in Isro’s five-decade history. A similar success would have resulted in celebrations in some space agencies around the world. But, on Tuesday morning, employees at the Satish Dhawan Space Centre (Shar) in Sriharikota were back to working on the half-assembled Polar Satellite Launch Vehicle (PSLV) C-39, which will soon be assembled fully and launched on June 23. used to concentrate on one mission,” says director P Kunhikrishnan. “Now we work in parallel to increase the throughput.”

By the end of this month, Isro would have made four rocket launches this year itself. Two of them were technically challenging, one being GSLV Mark III and the other the launch of 104 satellites on one rocket. By the month-end, Isro would also have built four satellites this year. They include the Gsat-19, a sophisticated satellite with high throughput that is expected to improve communication significantly in the country. It was put into orbit on Monday by the GSLV Mark III.

Even a casual observer would have noticed that the frequency of Isro’s missions has been increasing in recent times. Isro is also tackling missions of increasing sophistication, and slowly reducing the gap between India and the other space powers. Early next year, Isro will launch its second lunar mission, consisting of an orbiter, lander and rover.

If the government gives its approval, Isro will also begin work on a human mission sometime soon. With two different rockets and a third to be available soon, Isro will have an increasing presence in the global commercial market. When current chairman Kiran Kumar took over two and a half years ago, Isro was in good shape from a technical perspective.

The Mars mission had been accomplished and the GSLV, a thorn in Isro’s flesh for a long time, had been successfully flown. A cryogenic engine had been developed, and a human crew capsule tested by atmospheric re-entry. Through all these, the PSLV had been launching satellites with exquisite precision.

This was not always the case, as Isro went through a difficult phase about seven years ago. A GSLV launch failed and a cryogenic engine shut off prematurely. Another mission was aborted due to a fuel leak. “When you encounter difficulties,” says Kiran Kumar, “the concentration of the people goes towards solving those problems. But, once these problems are solved, the concentration is on how we can make things happen at a faster pace.”

The technical problems had delayed Isro’s programmes significantly. The GSLV should have been ready by 2009, but its first successful flight was only in 2014. The cryogenic engine should have been ready early in the millennium, but it was successfully flown only in 2014. Even the PSLV had a backlog. The government was aware of the problems, but continued to support the organization.

Soon after he took over, Kumar reengineered Isro to work faster. The senior management sat down and identified the bottlenecks. They strengthened the technical review system. They also optimized procurement and methods of testing. Separate divisions were created to deal with operations and R&D.



{Business process re-engineering.OFB has no such leeway nor inclination. IISB and IIMs should invite him and do case study to improve public sector enterprises.}

Projects were done in parallel. “The chairman asked us to push ourselves to the limit,” says S Somanath, director of the Liquid Propulsion Systems Centre (LPSC) in Thiruvananthapuram. The results were evident soon. The launches increased in frequency.

The backlog of satellites and launches has decreased, but national requirements are so large that Isro will be kept busy for a long time. The commercial opportunities are also not insignificant. “There is a shortage of launchers, whether it is higher capacity of lower capacity,” says Kumar. Isro, especially in the current high-speed environment, has the ability to respond quickly to market needs.

With PSLV launches increasing in frequency, satellite builders get opportunities for launch with low turnaround time. Isro’s launch costs also go down. None of these would have been possible if the technical problems had been left unsolved. In its nine-year history, GSLV Mark I and II together had notched five failures till December 2010. After Mark I failed in December 2010, Isro took two years before trying the next launch. In August 2013, GSLV Mark II flight was aborted due to a fuel leak. These failures delayed GSLV Mark III as well, as its facilities were used for Mark II for some time.

Isro subsequently did such thorough analysis of the GSLV that some of its engineers had said that they would not have known what to do if it had failed again in 2014. Its successful flight in January 2014 was a major turnaround for Isro. The preceding years were the period when Isro engineers mastered several technology areas, including the cryogenic engine, and developed confidence to take more risks. It also grabbed world attention through the Mars mission. “Two successful GSLV launches showed that whatever we worked out was successful,” says Kumar. “Technology is no longer an issue.” He could look at more challenging problems from 2015 onwards.

Isro now became very serious about adhering to the fixed launch date. Launch dates became sacrosanct. Only a newly-formed project management council had the right to change a launch date, and that too when done well in advance. Once Isro became serious about not changing the launch date, work culture changed for the better. People picked up speed. “In the aerospace sector, there is a belief that we should not hurry,” says Somanath. “But we can do faster. By doing things faster, nothing bad is going to happen.”

Isro then looked at its testing methods and decided to optimise them. Launch vehicle components were being tested in Thiruvanathapuram, transported to the launch centre at Sriharikota and then tested again. Isro decided to test them only at Sriharikota, thereby saving time. “We took a calculated risk,” says K Sivan, director of the Vikram Sarabhai Space Centre in Thiruvananthapuram.

{Mfg quality has improved that means for testing at component level is dispensed with and assembly level at Sriharikota is sufficient. Also reduces overstress of the packages by eliminating the component level testing. More reliable especially for electronic packages.}

If the components were found to be faulty during tests at Shar, Isro would have lost more time. However, engineers at VSSC by now have the confidence in their skills to take this risk. The biggest changes were reserved for Shar, which got big investments to create new facilities. Shar also started activities in parallel. It had built a solid stage assembly building, exclusively meant for GSLV Mark III.

This rocket had big solid motors – the third largest in the world – that could not be made by industry, and needed these special facilities for assembly. Isro also decided that the assembly building would be used for PSLV assembly as well. When the solid stage assembly building was being used for multiple vehicles, two vehicles could be assembled in parallel. Earlier the practice was to launch a rocket, clean up and repair the launch pad in about three weeks, and then start the new assembly. Now vehicles are assembled in parallel without affecting each other. Shar is building a third vehicle assembly bay that will be ready by the end of the year, and it will increase the efficiency even more.

Isro has two launch pads. From the first pad, it can launch six PSLVs. When the third assembly bay is ready, the throughput from the second launch pad will increase to ten, or probably 12 when teams are stretched fully. It means that Isro can have 18 launches from next year onwards.

Its launch capacity will remain at this level till it builds a third launch pad. Isro now has an extremely reliable vehicle in PSLV, which is being used by many satellite builders for launch. GSLV Mark II is now operational, and so Isro has a second vehicle for commercial launches. GSLV Mark III will be declared operational after one more flight, scheduled to happen after a year. It can launch satellites of up to 4,000 kg in weight.

As Isro developed more powerful launch vehicles, the weight of communication satellites kept going up. However, electric propulsion in satellites is promising to bring down their weight in the near future. So the GSLV Mark III will enter a lucrative commercial market soon. Big rockets are not optimized to launch 4-5-tonne satellites.

Arianspace, whose Ariane 5 rocket can launch payloads of more than ten tonnes, is now developing Ariane 6 for launching satellites of around five tonnes. So the two GSLV vehicles are addressing a market that may not go away soon. “I am confident that the GSLV Mark III will have a long life,” says K Radhakrishnan, former chairman of Isro.

Over the next few years, Isro is planning to start a joint venture with private industry to launch vehicles and make satellites. Isro itself is going to concentrate on future challenges, leaving the routine jobs to the joint venture. This entity is expected to start work by 2021. Isro’s biggest challenge after that will be to take humans to space.

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Re: GSLV-Mk III launch program/post-launch analysis

Postby disha » 09 Jun 2017 23:56

Varoon Shekhar wrote:Thanks guys, that's good to know. I suppose the concern now, is that the extra LAM firing to correct the perigee, might shorten the lifespan of the satellite. Certainly, that's a concern expressed on the NASA forum.


"NASA forum" are populated by multi-spectral multi-colored bakis. It is the space version of bakdef forum.

Having said that., the counter to it is very simple. And I updated that in the post., giving the Maruti 800 analogy. Yes the GTO shortfall is so so so minuscule that in its 3652.5 * 24 * 60 * 60 seconds of operation., 10 additional seconds of 440 N LAM firing will not impact its mission life in any way!

My thumb rule calculations (always wrong, always rounded off)., the shortfall in GTO velocity was some 15 m/sec. Firing 440 N LAM engine for 10 seconds should give it that requisite velocity.

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Re: GSLV-Mk III launch program/post-launch analysis

Postby Gagan » 10 Jun 2017 01:13

Singha wrote:can upper stage cryo stacking give benefits like a 2nd stage CE20 topped by a 3rd stage CE7.5 ? .... or the game is over and done with in the 1st stage power rating?

ISRO is developing a CE-60 engine for the first stage.
CE-20 is already the world's most powerful upper stage cryo!

Imagine a clustered CE-60 first stage with a CE-20 upper stage vehicle!!!

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Re: GSLV-Mk III launch program/post-launch analysis

Postby Kakarat » 10 Jun 2017 01:22

Gagan wrote:
Singha wrote:can upper stage cryo stacking give benefits like a 2nd stage CE20 topped by a 3rd stage CE7.5 ? .... or the game is over and done with in the 1st stage power rating?

ISRO is developing a CE-60 engine for the first stage.
CE-20 is already the world's most powerful upper stage cryo!

Imagine a clustered CE-60 first stage with a CE-20 upper stage vehicle!!!


Actually CE-60 is for RLV upper stage, SCE-200 is for the first stage and there seems to be a plan for SCE-400 for first stage

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Re: GSLV-Mk III launch program/post-launch analysis

Postby Gagan » 10 Jun 2017 01:27

CE-60 is bigger than the biggest Chinese 1st stage cryo!
Allah raham kare!!!
What is ISRO trying to do here, launch the entire ISS in one go? :eek:

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Re: GSLV-Mk III launch program/post-launch analysis

Postby Kakarat » 10 Jun 2017 01:37

Image

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Re: GSLV-Mk III launch program/post-launch analysis

Postby gakakkad » 10 Jun 2017 02:16

are there more details of the nuclear propulsion available ?...is the screenshot from any ISRO brochure?

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Re: GSLV-Mk III launch program/post-launch analysis

Postby ramana » 10 Jun 2017 04:27

See the ref to BARC for the nuke engine.

Look at the Isp. And LH2 fuel.

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Re: GSLV-Mk III launch program/post-launch analysis

Postby SSSalvi » 10 Jun 2017 05:29

Launch inclination is determined by the flight path .. 21.7 deg and 21.5( design value ) deg is not a big difference at all.
This could have resulted due to the lower launch velocity ( about 9.8 kms/sec against 10.2 kms/sec ) attained in this flight.

Orbit inclination change is inevitable in GEO launch from SHAR unless the last stage continues flight to align with equator in E-W direction so EVERY launch is followed by inclination change from 21 to 7 to 0 deg during maneuvers ( IRNSS excuse me please. ).

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Re: GSLV-Mk III launch program/post-launch analysis

Postby ramana » 10 Jun 2017 05:51

What about a new launch pad closer to Equator like in Lakshadweep?

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Re: GSLV-Mk III launch program/post-launch analysis

Postby Gagan » 10 Jun 2017 06:29

There is a launch site proposed (I think for polar launches, up north from Sriharikota) near Ganapavaram

They do have Thumba which is good for polar launches as well

If they launch geosats from Laccadive islands, I will recommend that people sell their houses in kerela and TN as these will be downrange, and the stages will fall down here
:mrgreen:

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Re: GSLV-Mk III launch program/post-launch analysis

Postby disha » 10 Jun 2017 07:21

Gagan wrote:CE-20 is already the world's most powerful upper stage cryo!


I thought NASA's RL-10 series (100-400 kN) are the most powerful upper stage cryo.

NASA also has 2000-3000 kN (10-15x times powerful than CE-20) RS-25.

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Re: GSLV-Mk III launch program/post-launch analysis

Postby ldev » 10 Jun 2017 08:05

Other than ISRO's PSLV and GSLV and the Ariane 5, all other heavy launchers are all stage liquid. Proton is hypergolic in all stages I think, Long March 5, Delta 4 heavy, Falcon 9 and Falcon 9 heavy are all RP-1/L0X in lower stages and some LH2/LOX in upper stages. Bezos' Blue Origin BE-4 will be methane/liquid oxygen. Long March 5, Falcon 9 and Delta heavy have no boosters and first stage is RP-1/LOX, high in specific impulse but a lower t/w ratio compared to solid boosters. Hence the initial lift-off and acceleration is very slow. SpaceX has gone liquid primarily for recovery/re-use, secondarily because it's a much smoother ride for astronauts if used for manned flights vs solid boosters.

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Re: GSLV-Mk III launch program/post-launch analysis

Postby Atmavik » 10 Jun 2017 08:39

disha wrote:
Gagan wrote:CE-20 is already the world's most powerful upper stage cryo!


I thought NASA's RL-10 series (100-400 kN) are the most powerful upper stage cryo.

NASA also has 2000-3000 kN (10-15x times powerful than CE-20) RS-25.


Disha Ji,

if one believes this wiki page we have the most powerfull CUS at 200 kN.

https://en.wikipedia.org/wiki/Cryogenic_rocket_engine

The RS25 is a first stage.

one possible path for ISRO to 10Tonne is as follows. is this accurate? or what could it be?

A larger dual S-250 solid strap-on boosters as compared to the S-200 boosters used in LVM3;
A semi-cryogenic core stage similar to LVM3 with SCE-200 engine;
A cryogenic third stage with a new CE-60 engine;

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Re: GSLV-Mk III launch program/post-launch analysis

Postby geeth » 10 Jun 2017 14:28

ldev wrote:Other than ISRO's PSLV and GSLV and the Ariane 5, all other heavy launchers are all stage liquid. Proton is hypergolic in all stages I think, Long March 5, Delta 4 heavy, Falcon 9 and Falcon 9 heavy are all RP-1/L0X in lower stages and some LH2/LOX in upper stages. Bezos' Blue Origin BE-4 will be methane/liquid oxygen. Long March 5, Falcon 9 and Delta heavy have no boosters and first stage is RP-1/LOX, high in specific impulse but a lower t/w ratio compared to solid boosters. Hence the initial lift-off and acceleration is very slow. SpaceX has gone liquid primarily for recovery/re-use, secondarily because it's a much smoother ride for astronauts if used for manned flights vs solid boosters.


I haven't understood the bolded part...higher ISP itself means lower weight, isn't it?

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Re: GSLV-Mk III launch program/post-launch analysis

Postby hnair » 10 Jun 2017 14:42

Gagan wrote:There is a launch site proposed (I think for polar launches, up north from Sriharikota) near Ganapavaram

They do have Thumba which is good for polar launches as well

If they launch geosats from Laccadive islands, I will recommend that people sell their houses in kerela and TN as these will be downrange, and the stages will fall down here
:mrgreen:



Thumba is out. Earlier days, it was considered remote, but now, there is Trivandrum city encircling it and it is already packed with many buildings that house vital R&D groups and test facilities like wind tunnels etc. Plus a southward trajectory will take it straight over the airport, core city areas etc

A better option would be a permanently anchored heavy oil rig kind of setup or a partially reclaimed outpost at some sand/rock/reef bank, some 50 km off-shore of Thumba. As per multi-year studies for the upcoming Vizhinjam port, the sea is rough (at sea-state 5 or rarely 6), for only 5% of time off Arabian Sea coast, unlike Bay of Bengal and its cyclone seasons. The costs of land acquisition would be far less and would not need dog-leg maneuvers, since Maldives archipelago is a bit off to the west

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Re: GSLV-Mk III launch program/post-launch analysis

Postby ldev » 10 Jun 2017 17:02

geeth wrote:I haven't understood the bolded part...higher ISP itself means lower weight, isn't it?


Sorry, what I meant is that because of it's lower density vs solids, propellant used per/sec is lower and hence it's acceleration is slower. So, that is why while LH2 has the highest ISP even in the atmosphere, because of it's low density, a huge volume tank will be needed if it's used as a first stage and it will need enormous pumps to inject adequate volumes for combustion to provide the minimum thrust needed at takeoff. That is why LH2/LOX is typically used in the upper most stage, although most two stage to orbit launchers for reasons of simplicity and mass production stick to the same propellant for both stages, typically RP-1/LOX.

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Re: GSLV-Mk III launch program/post-launch analysis

Postby nirav » 10 Jun 2017 17:59

Came across an important piece of information on the space 'bakdef'.
Apologies if it's been posted earlier.

X post. By 'vineethgk'
Below is a relevant quote from the chapter on GSLV-III development by S. Ramakrishnan from the book 'From fishing hamlet to the Red planet'.
Quote
In fact, with theBelow is a relevant quote from the chapter on GSLV-III development by S. Ramakrishnan from the book 'From fishing hamlet to the Red planet'.
Quote
In fact, with the launch corridor available from our spaceport at Satish Dhawan Space Centre (SDSC), Sriharikota, and the first and second stages impact zone constraints, the launch trajectory to GTO demands about 50 per cent of the total injection velocity to come from the cryogenic third stage.


It's one of the most basic but important factor in determining the configuration of Rockets selected by ISRO.
None of the spreadsheet configurations take this vital event into account, of where the first and second stages would eventually land.

This is just one of the factors that go into deciding a configuration for a launch vehicle.
It's easy to bah and pah at our configuration call it inefficient and quote brochure numbers from elsewhere and solve for 6 tons to GTO for mk2.
But where do the stages land ?
Bah and pah , Can't be the answer.


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Re: GSLV-Mk III launch program/post-launch analysis

Postby prasannasimha » 10 Jun 2017 20:11

RL 10 is 66.7 kN CE20 is 200 kN

(CE20 is indeed the biggest upper stage cryogenic engine in the world today.)

All the other ones are lower stage engines. The closest is the 132 kN Japanese LE5B engine.
For those cribbing about our strategy we have been able to build at least the most powerful upper stage fully cryogenic engine and that should be acknowledged.
We will obviously organically grow to the heavy lift launcher when we master semicryogenic technology which will be simpler to do since we have already mastered the staged combustion cycle engine.

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Re: GSLV-Mk III launch program/post-launch analysis

Postby prasannasimha » 10 Jun 2017 20:15

Orbit Determination results from this LAM firing are:

apogee X perigee height was changed to 35869 km X 35470 km.
Inclination is 0.101 deg.
Orbital period is 23 hr 50 min 10 sec

vis

Re: GSLV-Mk III launch program/post-launch analysis

Postby vis » 10 Jun 2017 20:21

prasannasimha wrote:RL 10 is 66.7 kN CE20 is 200 kN

(CE20 is indeed the biggest upper stage cryogenic engine in the world today.)

All the other ones are lower stage engines. The closest is the 132 kN Japanese LE5B engine.
For those cribbing about our strategy we have been able to build at least the most powerful upper stage fully cryogenic engine and that should be acknowledged.
We will obviously organically grow to the heavy lift launcher when we master semicryogenic technology which will be simpler to do since we have already mastered the staged combustion cycle engine.


There is a reason for ISRO having large upper stages that burn for far too long with far higher thrust.

ISRO has to avoid stages falling in the malaysia-indonesia region. Due to this constraint ISRO's all lower stages should either stage before reaching MY or burn all the way till they cross Papua. Building lower stages that burn all the way(Burn time grater than 800 sec) is not feasible and not economical.

For this reason ISRO burns high efficiency LH2 engines in the upper stages far too longer than any other rocket. This can be seen in the GSLV Mk2 where the CUS has the responsibility to give more than 60 % of the required Delta velocity. In foreign rockets lower stages provide most of the Delta velocity and hence their upper stages can be small.
Last edited by vis on 10 Jun 2017 20:23, edited 1 time in total.

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Re: GSLV-Mk III launch program/post-launch analysis

Postby disha » 10 Jun 2017 20:23

Atmavik wrote:if one believes this wiki page we have the most powerfull CUS at 200 kN.
https://en.wikipedia.org/wiki/Cryogenic_rocket_engine


Atmavik'ji., thanks for the link. RL10 is 110 kN* and CE-20 at 200 kN is twice as powerful. I did not realize it.

All ISRO needs is a Cryo-Engine of RS-25 class producing 2000-3000 kN and we are all set!

So ISRO can go either the route of Semi-Cryo producing eventually 2000 kN- and above or a Cryo route to the same. Either way it is a "scale up" and "budget" problem and not a technological challenge.

*RL10 was designed in late 50s and has evolved considerably. It is designed for 110 kN and clustered for upper stage of SLS.
Last edited by disha on 10 Jun 2017 20:36, edited 1 time in total.

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Re: GSLV-Mk III launch program/post-launch analysis

Postby disha » 10 Jun 2017 20:31

geeth wrote:I haven't understood the bolded part...higher ISP itself means lower weight, isn't it?


Specific impulse measures efficiency. While thrust is a brute strength.

It is like comparing fuel consumption of a maruti swift with an arjun tank., for the first "vehicle" it is measured in "Km per Litre" and for other it is measured in "Litres per Km".

You do not take a maruti swift to a battle and you do not drive around in city in an arjun tank even though one would like to.

[Sorry I had to sneak in some smarties :-D]

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Re: GSLV-Mk III launch program/post-launch analysis

Postby geeth » 10 Jun 2017 22:12

Specific impulse measures efficiency. While thrust is a brute strength.


But my query is about t/w ratio.

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Re: GSLV-Mk III launch program/post-launch analysis

Postby disha » 10 Jun 2017 23:59

I think it was meant to thrust per unit volume & not the thrust per weight.

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Re: GSLV-Mk III launch program/post-launch analysis

Postby disha » 11 Jun 2017 01:52

hnair wrote:Thumba is out. Earlier days, it was considered remote, but now, there is Trivandrum city encircling it and it is already packed with many buildings that house vital R&D groups and test facilities like wind tunnels etc. Plus a southward trajectory will take it straight over the airport, core city areas etc


I thought it was due to the strikes that ISRO decided to move launch activities to SHAR which resulted in more strike. BTW, when Morarji Desai as PM visited Thumba., the workers went on strike and the PM personally intervened to get the striking workers call off their strike!

SHAR is a great range now., further up for Polar launches ideal launch site will be around Dwarka. In fact., when RLV can have a second landing strip in rann of kutch.

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Re: GSLV-Mk III launch program/post-launch analysis

Postby Gagan » 11 Jun 2017 02:59

China's Long March 5, their most powerful rocket, which has had one flight so far, and with its 2nd flight coming up next month (July 1)

This rocket looks like the GSLV MK4 (With 4 boosters instead of 2 boosters as in Mk3)
First stage: 2xYF-77 (700kN Cryo). 4 boosters of 2xYF-100 (1200kN Semi cryo each)
Second stage: YF-75 (88 kN Cryo)

I'm like Meh! This is easily in ISRO's reach !


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