Indian Space Program: News & Discussion - Sept 2016

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Re: Indian Space Programme Discussion - Sept 2016

Postby geeth » 12 Sep 2016 19:47

SpaceX’s reusable Falcon 9: What are the real cost savings for customers?

Stage after landing
KOUROU, French Guiana — Now that SpaceX appears on the verge of being the first to reuse rocket hardware since NASA with the U.S. space shuttle, investors and competitors are sharpening their pencils to assess the business case.

The prima facie appeal of reusing rockets has always obscured the challenges of refurbishing, at low cost, a rocket stage and engine bloc that has suffered the stresses of hurtling through the atmosphere in advance of landing.

“It’s quite fundamental,” SpaceX founder Elon Musk said April 8 after the Falcon 9 first stage made a clean touchdown on a drone ship located offshore the Cape Canaveral Air Force Station, Florida, as part of a successful mission to deliver supplies to the international space station for NASA. The stage has since been returned to port and will be repeatedly test-fired to determine its fitness for reuse as early as this year.

“It’s just as fundamental in rocketry as it is in other forms of transport – such as cars or planes or bicycles,” Musk said in a post-launch briefing.

NASA engineering veterans of the space shuttle would surely agree about its being fundamental. But after beating their heads against the problem for years, they also would say it’s much more difficult than hopping back into your car.

“The SSMEs were reusable,” Dan Dumbacher, former NASA deputy associated administrator for exploration systems development, said of the space shuttle main engines. “We tried to make them reusable for 55 flights. Look how long and how much money it took for us to do that, and we still weren’t completely successful for all the parts. I want to be realistic: We are not as smart as we think we are and we don’t understand the environment as well as we think we do.”

Dumbacher was speaking in April 2014, before Hawthorne, California-based SpaceX succeeded in landing the Falcon 9 first stage, first in December on a pad near the launch site, and then during the April 8 mission. But his caution related not to the fact of landing safely, but to the economics of refurbishment.

SpaceX is a privately held company that does not publish its financial statements, making a detailed cost analysis difficult. Outsiders are left with piecing together what they can, based on SpaceX’s public statements.

In March, SpaceX President Gwynne Shotwell said the company could expect a 30 percent cost savings from reusing the first stage. If this translated into a 30 percent price reduction to customers, that would drop Falcon 9’s advertised price to $42.8 million from today’s $61.2 million.

When measured by contract volume, SpaceX’s biggest customer is SES of Luxembourg. SES has said repeatedly it is willing to be the inaugural customer for a reused first stage, but would like the price to move closer to $30 million, at least for the first flight.

The interest of SES, a publicly traded company, in rocket reuse has set in motion analyses by investment banks covering the commercial satellite telecommunications industry. The latest is from Jefferies International LLC.

In an April 25 report, Jefferies takes the $61.2 million list price for a Falcon 9 launch and assumes SpaceX makes a gross margin of 40 percent on the launch, leaving a direct per-launch cost to SpaceX of $36.7 million. This includes the costs of the fueled rocket, and of launch campaign.

Confusing and occasionally contradictory statements about the cost savings to SpaceX -- and to its customers -- derived from multiple reuse of the Falcon 9 rocket's first stage has made it difficult to forecast reusability's impact. Investment analysts at Jefferies have made a disinterested attempt to look at what satellite fleet operators might expect in savings. Conclusion: between 21 and 40 percent from current prices. Credit: Jefferies
Confusing and occasionally contradictory statements about the cost savings to SpaceX — and to its customers —derived from multiple reuse of the Falcon 9 rocket’s first stage has made it difficult to forecast reusability’s impact. Investment analysts at Jefferies have made a disinterested attempt to look at what satellite fleet operators might expect in savings. Conclusion: between 21 and 40 percent from current prices. Credit: Jefferies
SpaceX founder Elon Musk has said the first stage accounts for about 75 percent of the total vehicle cost. If the 40 percent gross-margin estimate were correct, that would mean a total first-stage cost of $27.5 million.

Musk has said the first-stage engine could be reused dozens of times. Jefferies assumes it is used 15 times.

If SpaceX passed on to its customers 50 percent of the cost savings, the company could reduce today’s Falcon 9 price by 21 percent, to $48.3 million, Jefferies concludes.

If SpaceX gave customers 100 percent of the savings, the launch price would drop by up to 40 percent, to $37 million.

“There are ongoing challenges in translating a reused rocket to tangible capex savings – worries about it failing, insurance implications, retrofitting turnaround, building up a critical mass of reused first stages in the warehouse,” Jefferies said. “But the direction of travel is clear.”

Musk said the fuel used on a Falcon 9 is between $200,000 and $300,000. Reserving fuel in the first stage for landing adds mass to the vehicle and deprives it of performance, effectively carrying fuel instead of extra payload — a penalty that expendable rockets do not need to pay. Musk was addressing not the performance penalty, but the issue of fuel cost, which is a non-issue in the overall economics of reusability.

While focusing on the first stage, SpaceX would like to return the rocket’s fairing as well. “That will certainly help, because each of these costs several million,” Musk said.

SpaceX has not addressed how many launches per year it would need to close the business case for reusability. But this is a key issue.

The economies of scale that SpaceX achieves through Falcon 9’s design of using identical engines throughout the vehicle – nine on the first stage and one on the second – will likely be diluted once reused first stages are added into the mix.

The amount of dilution will depend on how many times the stages are reused, and what SpaceX can reasonably assume as an annual launch rate.

SpaceX has not publicly disclosed what it views as a minimum acceptable launch cadence.

SpaceX’s principal competitor, Arianespace of Europe, sees this issue as a potential death blow for any European attempt to reuse its Ariane rockets. In fact, it’s a double whammy for Europe because the same problem that makes it uneconomic for Arianespace makes it necessary for SpaceX to become even more aggressive in the global commercial launch market.

Arianespace Chief Executive Stephane Israel, in an April 23 briefing at Europe’s Guiana Space Center here on the northeast coast of South America, said Europe’s launch sector can only guess at how much SpaceX will need to spend to refurbish its Falcon 9 first stages.

Israel said European assessments of reusability have concluded that, to reap the full cost benefits, a partially reusable rocket would need to launch 35-40 times per year to maintain a sizable production facility while introducing reused hardware into the manifest.

Arianespace’s Ariane 6 rocket, scheduled to debut in 2020, is forecasted to launch 12 times per year starting in 2023, when the current Ariane 5 vehicle is retired.

This rate may increase depending on developments in the commercial market. Seven of the 12 annual Ariane 6 campaigns will be devoted to commercial launches, each carrying two satellites. The five other launches will be for European government customers.

Israel’s argument, which he has made before, is that even if first stages can be recovered and refurbished in a cost-effective way, the launch rate needed for maximum cost savings – and hence price reductions to customers – is beyond Europe’s reach.

The only nations today whose governments are launching sufficiently often to reach those rates are the United States and China, and even these government markets may be insufficient, in and of themselves, to close the business case.

That means any launch provider introducing reusability will have a maximum incentive to search for commercial business outside its domestic market.

The scenario European launch officials fear is one in which SpaceX succeeds in refurbishing stages at a relatively low cost, and then – to close reusability’s business case — becomes even more aggressive on the international market, which is where Arianespace generates most of its revenue.

http://spacenews.com/spacexs-reusable-f ... customers/



IMO this whole exercise of reuse just shows the desperation of unkeel...they are trying to protect the launch market but are going to miserably fail. Any reuse of moving pars like turbo pumps tc needs thorough testing and even then there is a lot of risk of failure. In this respect the the solid rockets scores better for reuse because they are relatively simpleton. But again, what is the cost of rocket fuel burnt compared to the value of empty motor recovered? What about the electronics most of which are stacked in upper stages...to top it all we have the dead example of space shuttle. Even if we discount the human factor involved, there is no scope for lethargy, because the payload is costly and reliability is paramount to retain a customer.

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Re: Indian Space Programme Discussion - Sept 2016

Postby prashanth » 12 Sep 2016 20:13

From that article,

"The proposal was to develop a 75-tonne thrust semi-cryo engine, similar to the 68.5-tonne Saturn V engine, and we could have easily achieved that :eek: . And by clustering four of these, we would have had an extremely powerful booster by now, equivalent to the most advanced rockets, which could have formed the basis for our main version of the PSLV. And in parallel a 7.5-tonne thrust LOX-LH cryogenic engine could have been developed. We have lost valuable time," he observed.

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Re: Indian Space Programme Discussion - Sept 2016

Postby kit » 12 Sep 2016 21:16

That was the same thing China did / is doing .. no big tech breakthroughs

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Re: Indian Space Programme Discussion - Sept 2016

Postby kit » 12 Sep 2016 21:23

And if ISRO can get to that heavy lift capability like a Saturn in 5 years ..it may not be such a bad thing

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Re: Indian Space Programme Discussion - Sept 2016

Postby abhik » 13 Sep 2016 00:03

Re returning the whole first stage vs just the engines, Jeff Bezos unveils Blue origin's next launcher:-
Image

https://twitter.com/JeffBezos/status/77 ... 78304?s=09

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Re: Indian Space Programme Discussion

Postby vina » 13 Sep 2016 05:55

dhiraj wrote:Hopefully many may have already read it, still sharing (good read)
http://www.frontline.in/static/html/fl2 ... 404300.htm


Very well written article by somone who knows exactly what they were writing about and extremely well researched as well. It is not without reason that "Commie Central" - Frontline does the best science journalism in India.

However, what they are leaving out unsaid in the article is very simple. India's missile tech R&D program was embedded with space launch program and it was left largely unmentioned. The clean separation between military and civil happened only in the mid 90s, or so and I remember even a visit by Larry Pressler to SrihariKota around that time.

If you keep that in mind, it explains a lot of why the particular tech choices of solids and industrial scale UDMH/N2O4 and WeakAss engines were made over Kerosene/LOX. If given a constraint on manpower and resources , the tech choices ISRO made gave them the option on both space launching and also tech development for strategic missiles. In fact, the SLV 3 first stage is what was used in Agni I as first stage! Kalam himself shifted between DRDO and ISRO.

But all that is history. Now the choices made in clustering two WeakAsses for L110 is inexplicable. They should have bundled 4 and realised the full potential of GSLV MK1/2 and also GSLVMKIII , but now they did 2 and looking at their plans/product strategy, they should replace the 2 WeakAsses in L110 with 2*2MN Kerosene/LOX, but no, they are putting in only one there...

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Re: Indian Space Programme Discussion

Postby hnair » 13 Sep 2016 09:05

vina wrote:
If you keep that in mind, it explains a lot of why the particular tech choices of solids and industrial scale UDMH/N2O4 and WeakAss engines were made over Kerosene/LOX. If given a constraint on manpower and resources , the tech choices ISRO made gave them the option on both space launching and also tech development for strategic missiles. In fact, the SLV 3 first stage is what was used in Agni I as first stage! Kalam himself shifted between DRDO and ISRO.

But all that is history. Now the choices made in clustering two WeakAsses for L110 is inexplicable. They should have bundled 4 and realised the full potential of GSLV MK1/2 and also GSLVMKIII , but now they did 2 and looking at their plans/product strategy, they should replace the 2 WeakAsses in L110 with 2*2MN Kerosene/LOX, but no, they are putting in only one there...


No more of usage of term "WeakAsses" for a rocket engine that was developed painstakingly by really bright bunch of people a few of whom was then tortured as spies. Particularly after reading this article about how they were uprooted to Vernon, leaving behind spouses and kids.

Class of 1974: Rocket science & reminiscences

It was never funny, when you use that ridiculous term for an engine that has growled up faithfully when India needs to put tonnage into space. Expressing your wishes and technical opinion are fine.

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Re: Indian Space Programme Discussion - Sept 2016

Postby prasannasimha » 13 Sep 2016 13:36

So easy to say cluster 4 when we had not yet learnt to cluster two. (Yes we can even cluster 6-8 10 and so on) Once we have learnt clustering with the 2 Vikas engines we are moving to cluster other engines.
Derogatory terms for the efforts have to also keep in mind that not many countries can even launch rockets let alone the needed payloads into space and we were working in a technology denial regime. Let us not forget that both US and Russia were flounering till their "captive" Verner Von Braun gave a kickstart. The same engines ahve allowed us to put an orbiter on Mars and well we have done the best with what technology we have developed at the time.

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Re: Indian Space Programme Discussion - Sept 2016

Postby sooraj » 13 Sep 2016 14:00

Gyan wrote:There is interesting talk by Mr. Somnath of ISRO at https://www.youtube.com/watch?v=iHgn5m139uA

Does someone have access to clear pictures of the slides. There is huge lot of info inthe slides which has been released for the first time by ISRO in public domain. The Camera work in this video seems to be very poor.



From the slides,

10 ton thrust LOX - Methane in development

ISRO developing 2 stage RLV(2.5 to 3T in LEO)

Development of 300 mN thruster for all electric propulsion spacecraft

Laser Photonic propulsion

Advanced propulsion concepts( plasma propulsion and nuclear propulsion)

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Re: Indian Space Programme Discussion - Sept 2016

Postby dhiraj » 14 Sep 2016 11:49

http://www.isro.gov.in/sites/default/fi ... _video.mp4

Video from onboard camera of GSLV-F05

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Re: Indian Space Programme Discussion - Sept 2016

Postby vina » 14 Sep 2016 12:24

So easy to say cluster 4 when we had not yet learnt to cluster two

Prithvi I

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Re: Indian Space Programme Discussion - Sept 2016

Postby Gyan » 14 Sep 2016 14:51

ISRO Seems to be well set to achieve 25 tons to GTO by 2030 without any major technology challenge with 90%+ indigenisation. Hence our Space Odessy is going well.

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Re: Indian Space Programme Discussion

Postby nirav » 14 Sep 2016 16:04

hnair wrote:
vina wrote:
If you keep that in mind, it explains a lot of why the particular tech choices of solids and industrial scale UDMH/N2O4 and WeakAss engines were made over Kerosene/LOX. If given a constraint on manpower and resources , the tech choices ISRO made gave them the option on both space launching and also tech development for strategic missiles. In fact, the SLV 3 first stage is what was used in Agni I as first stage! Kalam himself shifted between DRDO and ISRO.

But all that is history. Now the choices made in clustering two WeakAsses for L110 is inexplicable. They should have bundled 4 and realised the full potential of GSLV MK1/2 and also GSLVMKIII , but now they did 2 and looking at their plans/product strategy, they should replace the 2 WeakAsses in L110 with 2*2MN Kerosene/LOX, but no, they are putting in only one there...


No more of usage of term "WeakAsses" for a rocket engine that was developed painstakingly by really bright bunch of people a few of whom was then tortured as spies. Particularly after reading this article about how they were uprooted to Vernon, leaving behind spouses and kids.

Class of 1974: Rocket science & reminiscences

It was never funny, when you use that ridiculous term for an engine that has growled up faithfully when India needs to put tonnage into space. Expressing your wishes and technical opinion are fine.


Thank you very much. The term is not funny nor anything closer to the truth.
The engine under the ass of a smart Alec can very much put that Alec and the nonsense into orbit for good.

Hope the term used by just the one person is banned from usage.

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Re: Indian Space Programme Discussion - Sept 2016

Postby Gagan » 14 Sep 2016 16:45

Even the 2 vikas cluster has flown on the Mark 3.
It is surprising, and late, but now ISRO is clustering its engines.
But the strap ons are a form of clustering, alebit not deriving fuel from same tanks
I thnk there is an impetus towards higher volumes & filling the transponder gap for the nation, which btw is expected to grow exponentially now.

Would love to see two heavies launched to GTO simultaneously on a mark-3

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Re: Indian Space Programme Discussion - Sept 2016

Postby dhiraj » 14 Sep 2016 20:57

Thank you very much. The term is not funny nor anything closer to the truth.
The engine under the ass of a smart Alec can very much put that Alec and the nonsense into orbit for good.

Hope the term used by just the one person is banned from usage.


With due respect, it would have been of great help if someone can help clarify for the below :
- Why clustering engine was a super tough act in the first place which prevented ISRO to work on it early
- Why 4 engine in MK.3 core could not be clustered while 2 was done. Please understand why something is being called weak and in what context.
Running a Formula 2 car in Formula 1 race will not be an optimum solution. Vikas engine per se is not weak (and i still don;t understand the sensitivity to the term), rather in what context and configuration it is being used.
Check the Chinese launch vehicles, IIRC multiple decades they have launched vehicles by clustering more and more liquid engines with similar or lower performance compared to Vikas
- Semi - Cryo was planned only after 2005 while MK.3 configuration was done much early.

I believe ISRO two understand these weakness in design and thus the push towards semi-cryo core etc.
Addition point : Please check under whose leadership and later there was real thrust to increase launch vehicle capability.

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Re: Indian Space Programme Discussion - Sept 2016

Postby hnair » 14 Sep 2016 21:19

Please understand why something is being called weak and in what context.


dhiraj, enough. vina certainly does not need your advocacy and rest of his technical posts are usually worth reading. But you on the other hand, 90% of your past posts has been a whinefest about ISRO over matters that, rather suspiciously, you are hardly interested in hearing a straight answer.

Informal warning this time. No further warnings in your case.

Everyone else, let us move on

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Re: Indian Space Programme Discussion - Sept 2016

Postby hnair » 14 Sep 2016 21:59

dhiraj, one month off for posting, despite an informal warning

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Re: Indian Space Programme Discussion - Sept 2016

Postby prasannasimha » 15 Sep 2016 00:06

Clustering of solid boosters and liquid engines are two different things. Solid Boosters rate of burn is controlled by their grain configuration and once started cannot be stopped or throttled at will whereas liquid engines can have variable flow and thrust generated and usually the source of fuel and oxidizer are one large tank for each so when you cluster you need to efficiently manage their firing but also distribute the fuel and oxidizer in a proper manner. For eg when there is a pitch, roll or yaw the shape of the ullage space changes and the turbo pumps must account for this and similarly a host of other problems that have to be factored in to allow the controlled explosion to proceed in a controllable manner and not haphazardly. Even the Russians had problems with this just last year even though they have such a reliable Soyuz system. Also thrust vectoring algorithms need to be coordinated when you use it and automatically becomes more complex with multiple engines firing simultaneously. There a host of other issues.
If you ask why SpaceX etc are able to do it so fast - it is because they have NASA engineers as consultants, recieve classified information blue prints etc etc and already have basic supply chains which were historically supplying NASA and with active NASA collaboration.
Just as a reminder of the complexity do not forget that just a few days back a Lng March rocket failed to meet its objective.
Success has many Fathers but failure has none.

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Re: Indian Space Programme Discussion - Sept 2016

Postby disha » 15 Sep 2016 06:40

abhik wrote:Re returning the whole first stage vs just the engines, Jeff Bezos unveils Blue origin's next launcher:

https://twitter.com/JeffBezos/status/77 ... 78304?s=09


Abhik'Ji - that is an impressive rocket., and looks very good and also the booster returns back to earth after its flight.

But.,

1. Does it fly?
2. When will it fly?
3. Will it fly regularly - like some 20+ consecutive launches *without* *any* mishap?
4. Will it be cost effective? And if the answer is yes - How?
5. What market will it serve? Space Cargo (water to ISS for example)? Human Space Exploration? Launching of EO Sats? Comm Sats? All of the above? One of the above? Some of the above?

I think answers to question specific to Blue Origin rockets itself must be taken up in 'International space' thread.

But I do have to point out., for folks going ga-ga over Blue Origin and SpaceX., fact is they are looking over at ISRO and trying to learn how ISRO is doing what it is doing. There is a healthy competition and no serious rocketeer is running down other's program (even Chinese!).

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Re: Indian Space Programme Discussion - Sept 2016

Postby Bheeshma » 15 Sep 2016 12:57

This would be awesome...

http://www.thehindu.com/news/cities/ban ... 055622.ece

ISRO may do a 68-satellite single launch next year

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Re: Indian Space Programme Discussion - Sept 2016

Postby putnanja » 15 Sep 2016 17:03

First images from Insat-3DR available at http://www.isro.gov.in/gslv-f05-insat-3 ... 3dr-imager ...

Image

Image

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Re: Indian Space Programme Discussion - Sept 2016

Postby SSridhar » 15 Sep 2016 18:20

As ISRO has noted, the moon is seen at the bottom of the second image above.

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Re: Indian Space Programme Discussion - Sept 2016

Postby rsingh » 15 Sep 2016 22:42

Apart from moon, nothing new. This could be easily from good old Rohini and Araybhatta times. Worst PR ever. At least they could put coloured pic.

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Re: Indian Space Programme Discussion - Sept 2016

Postby Mollick.R » 15 Sep 2016 23:22

Finally a good quality onboard camera Video of GSLV-F05. :D :D

http://www.isro.gov.in/gslv-f05-insat-3dr/video-onboard-camera-of-gslv-f05

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Re: Indian Space Programme Discussion - Sept 2016

Postby Prem » 15 Sep 2016 23:27

https://www.youtube.com/watch?v=kmLHlbhpzEs
russian media: US congress got affaid of isro

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Re: Indian Space Programme Discussion - Sept 2016

Postby disha » 16 Sep 2016 02:11

prasannasimha wrote:Clustering of solid boosters and liquid engines are two different things. Solid Boosters rate of burn is controlled by their grain configuration and once started cannot be stopped or throttled at will whereas liquid engines can have variable flow and thrust generated and usually the source of fuel and oxidizer are one large tank for each so when you cluster you need to efficiently manage their firing but also distribute the fuel and oxidizer in a proper manner. For eg when there is a pitch, roll or yaw the shape of the ullage space changes and the turbo pumps must account for this and similarly a host of other problems that have to be factored in to allow the controlled explosion to proceed in a controllable manner and not haphazardly.


Very well put. At the same time the definition of 'clustered' itself is loose. Does it mean - a set of engines tied together & fired together or does it mean a set of engines sharing the same tankage?

Why is clustering proposed in the first place? For reliability or for providing 'more oomph to GTO - like 10 Ton to GTO'** -

Clustering was meant for reliability. If one has clustered 4 engines., if one-fails - another can be shutdown and the rocket still achieves its mission objectives. Chances of 1 in four failing in flight are low. 1 in 9 is even lower!

Prasanna'ji and others., please do not forget that by the former definition PSLV, GSLV-MkII and GSLV-MKIII have clustered engine boosters. PSLV has PSOM Clustered with the first stage to make a solid-solid clustered engines with SITVC to provide pitch/yaw control. GSLV-MKII has Solid booster paired with Liquid strap-ons to form a Solid-Liquid clustered engines. Note that it has four liquid strap-ons which are fired simultaneously. On GSLV-MKIII again the liquid is clustered closely to share the same tankage. And paired with the solid boosters.

Sharing the same tankage has its complications. The key question there is: Can one obtain better reliability by clustering small engines to a single tankage or a single large engine? It is a deceptively simple to just say former is better than the later since the failure probability of 2 in say 9 engines (SpaceX/Octaweb configuration) is lower and hence clustering is a good idea. However clustering creates its own complexities which take away from reliability.

However study after study has pointed out that it is not a simple statement to say clustering is better over a single engine. One has to look at technology at hand, development effort, experience, time and mission objectives to arrive at yes - we will do clustering or no - will not do clustering. Now this is the clustering with shared tankage.

**Still have not received a convincing answer on what commercial use does one have with 10 Ton to GTO. Note 'commercial' use. I can understand sending a 4-ton astronomy science mission to L1 point. But 'commercial' use.

Just as a reminder of the complexity do not forget that just a few days back a Lng March rocket failed to meet its objective.
Success has many Fathers but failure has none.


The LM4C most likely suffered a failure in upper stage which is a dual-clustered liquid propellant (UDMH/N2O4) engine. Solution of clustering to overcome reliability issues actually failed here! Leading to overall mission failure. The irony.

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Re: Indian Space Programme Discussion - Sept 2016

Postby prasannasimha » 16 Sep 2016 08:11

^ I hope you realize that this is the fiorst light image of the camera and this camera is not a color camera but uses other paramters(for example IR spectrum watever vapor channel) Or do you want a photo-shopped color image ?

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Re: Indian Space Programme Discussion - Sept 2016

Postby prasannasimha » 16 Sep 2016 08:16

Clustering is not only to reduce failure but also to simplify engine design and output, fuel fraction delivery rate etc. Clustering of multiple but separately fired engines has been done by ISRO for eg the strap on boosters etc but that is not "clustering" that is being referred to. It is the coordinated firing of multiple engines with common fuel oxidizer source where the challenge is which was what was being undertaken by L110. The strap on boosters were liquid engines but not considered truly "clustered"

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Re: Indian Space Programme Discussion - Sept 2016

Postby vina » 16 Sep 2016 11:50

prasannasimha wrote:Clustering is not only to reduce failure but also to simplify engine design and output, fuel fraction delivery rate etc. Clustering of multiple but separately fired engines has been done by ISRO for eg the strap on boosters etc but that is not "clustering" that is being referred to. It is the coordinated firing of multiple engines with common fuel oxidizer source where the challenge is which was what was being undertaken by L110. The strap on boosters were liquid engines but not considered truly "clustered"


This is hair splitting and one can argue what clustering is until the cows come home. Whether individual engines (turbo machinery + nozzle) feeding of common tankage is clustering, or whether individual engines (complete with individual tanks) slapped together is clustering . That is besides the point and is just a matter of detail (the former will have a little bit better mass fraction, nothing earth shattering).

What DOES matter is this. If instead of putting the 4 liquid engines as boosters like they have done currently , they had slapped them together in the core as a bundle/cluster (whatever term you want, you can choose) , and put two solids on the side as booster and dropped those when spent, GSLV MK1/2 and also GSLV MK3 will have higher mass fractions to orbit.

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Re: Indian Space Programme Discussion - Sept 2016

Postby rsingh » 16 Sep 2016 21:06

prasannasimha wrote:^ I hope you realize that this is the fiorst light image of the camera and this camera is not a color camera but uses other paramters(for example IR spectrum watever vapor channel) Or do you want a photo-shopped color image ?


I knew somebody is going to write such thing. Do you see (in the pic) what you say. Pour Moi it is simple black-n-white and I can not differentiate if it was taken in 1960 or 2016.

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Re: Indian Space Programme Discussion - Sept 2016

Postby Amber G. » 17 Sep 2016 09:39

Sorry if already posted... This is youtube version which may be easy to distribute.. https://www.youtube.com/watch?v=ez1r2UrGwkA
A few days ago ISRO released Video of GSLV-F05/GSLV F05 Onboard Camera view. Awesome view of GSLV MK II separations of various stages and putting INSAT-3DR into specified Orbit.

Last edited by Amber G. on 17 Sep 2016 10:17, edited 1 time in total.

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Re: Indian Space Programme Discussion - Sept 2016

Postby RoyG » 17 Sep 2016 10:09

Hard to imagine it all started from this. India will forever be indebted to these guys.

Image

Image

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Re: Indian Space Programme Discussion - Sept 2016

Postby vina » 17 Sep 2016 14:21

Amber G. wrote:Sorry if already posted... This is youtube version which may be easy to distribute.. https://www.youtube.com/watch?v=ez1r2UrGwkA
A few days ago ISRO released Video of GSLV-F05/GSLV F05 Onboard Camera view. Awesome view of GSLV MK II separations of various stages and putting INSAT-3DR into specified Orbit.



At 0:53, the second stage ignites, at 0:57, the separation and interstage truss is clearly seen, with the rocket exhaust bouncing off the tank top of the 1st stage and the next frame shows the entire 1st stage with the 4 boosters fall of together as one integral unit (sigh)...(shows how each booster connected to the core by 4 rows of connecting rods) at 1:07, camera blocked by the heat shield falling away, heat shield seen in 1:08, then at 1:30, the view switches the the camera on top of the 2nd stage, and shows the bottom of the cryogenic stage, which starts pulling away at 1:31, at 1:34 the cryogenic stage is clearly seen at a distance. The cryogenic main engine is not lit, the two steering engines are firing , giving the thrust to pull the stage away and also providing the "settling" thrust for the propellants.

The cryogenci engine's nozzle is covered by some sort of cap that is black in color to which some attached cord is seen.At 1:41, an explosive cord /shaped charge goes off (seen starting from the right on the nozze) ,that severs the nozzle cover at 1:43 that blast wave is seen, at 1:44, some cover and a cord that was clearly visible are seen flying past the camera, at 1:45, the blast wave is gone, the nozzle interior is seen as all black, with a white dot in the center (combustion starting?) at 1:46, the entire nozzle is filled with flame (bright dot at center though) , that pulses for a second, the flame stabilizes into a uniformly bright well lit front and the cry stage is off on it's way. At 1:45, the cover/seal seen flying off on the left of the screen, a black, truck tyre like thing.

So, really there is a good 12 second difference between the "Thurd Stage Separatud" call out and "Engine Perfaarmance Naarmal". What ignites first are only the 3 of the 4 hydrogen/oxygen flames that come on (ie, the 2 steering engines and the combustor to drive the turbo pumps) when the stage is separated. The main engine's flame comes on only after a good 12 seconds after a series of complex steps (which I would think would be the fuel and oxygen booster pumps spooling up and building head, the main turbine and pump spooling up) and the drama visible in the camera of the seal /plug ejected out so dramatically .

I wonder how all this will play out in MKIII with the CE20 engine. That engine is different (other than it being open cycle vs staged combustion), it does not have the two steering engines and the engine is mounted on gimbals . I guess when we see the videos of MKIII/CE20, we will see the stage fire through the interstage truss just before the previous stage cuts out and flies out fully lit. We are not going to see the 12 second or so gap like we see in MK2 with the CE 7.5.

Such great engineering . Pah, If only they fix the eyesore and sub optimal nonsense we see at 0:57.

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Re: Indian Space Programme Discussion - Sept 2016

Postby Neela » 17 Sep 2016 15:05

vina wrote:
What DOES matter is this. If instead of putting the 4 liquid engines as boosters like they have done currently , they had slapped them together in the core as a bundle/cluster (whatever term you want, you can choose) , and put two solids on the side as booster and dropped those when spent, GSLV MK1/2 and also GSLV MK3 will have higher mass fractions to orbit.


You made this comment earlier and I am trying to understand your point of view.
- Missile & space program intertwined until year 2000 leading to relying on solid fuel stage.

Also the frontline article mentions about the "Solid" team nixing the development of SemiCryo and Liquid progrms.

"People connected with Vikas and the proponents of solid propellants pulled it down, in particular one man who was interested in pushing the imported Vikas," adds Sadashiva. Although he refrained from naming the person, it is amply clear that he was referring to Dr. A.E. Muthunayagam, who led the Vikas programme at ISRO's Liquid Propellants Systems Centre (LPSC).


Are you saying arguments of consolidation, optimal use of funds and reliability would have been used in favor of solids. And that this has shaped the program as we see it now?

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Re: Indian Space Programme Discussion - Sept 2016

Postby Neela » 17 Sep 2016 15:07

General question
If ISRO had pursued its SCE engine ( which the Frontline article says was nixed ) , how would the stages look like today and what payloads could have been achieved to GTO?

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Re: Indian Space Programme Discussion - Sept 2016

Postby prasannasimha » 17 Sep 2016 15:27

^ It is not a payload fairing or heat shield it is an interstage truss which is open lattice to allow hot firing.

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Re: Indian Space Programme Discussion - Sept 2016

Postby prasannasimha » 17 Sep 2016 15:27

We hadn't got the SCE working and who knows ?

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Re: Indian Space Programme Discussion - Sept 2016

Postby Gagan » 17 Sep 2016 16:34

About clustering.
I thought the reason engines are being clustered is because these engines don't have enough thrust by themslves. Once you cluster, you get that total thrust that can overcome the rocket's weight and then give you the required velocity.
Rockets thrust are so tneuously designed that if even one component fails, that will end the mission. There is no such thing as one of the 9 engines failing and the mission will still be successful, it will likely result in a series of compounding boost defecits stage after stage, that will lead to a failure of the launch mission.

This a quick and dirty way of launching heavier satellites even if the engine thrust is inadequate. Due modelling can easily resolve any problems wrt fuel distribution during flight. ISRO wind tunnel tests all its rockets, surely if they can build cryo engines, they can easily master clustering and its relatively simpler challanges.

The usefulness of a 10 ton GTO is being able to launch multiple satellites. Ariane 5 does 2 heavies to GTO regularly. India has a growing transponder gap, that is growing inspite of ISRO's efforts. With the tech & economic boom going on, and digitalizationof everything, things like reliance Jio or the GST tax system will demand HUGE transponder volumes in themselves. Imagine a billion people paying taxes electronically!
ISRO sorely needs higher volumes for the next decade or so, like a Geo sat every other month or so, 2 GSLVs a year is too little.
And ISRO has to start selling satellites to asian, african & south american customers. None of these nations have space launchers,and the cheenis are making inroads!

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Re: Indian Space Programme Discussion - Sept 2016

Postby Gagan » 17 Sep 2016 16:46

In 5 years half of the geo sats will need to be replaced, in 8-9 yrs the IRNSS sats will need to be replaced, and we are talking about further augmenting all these systems.
Every time at an ISRO Ariane launch, our people are saying that this will probably our last mission with arianespace, because we have an expanding domestic launch program of our own.

India should not be a cuddly elephant, it should be an angry, rampaging, mammoth, please!

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Re: Indian Space Programme Discussion - Sept 2016

Postby geeth » 17 Sep 2016 17:37

I am looking at the "suboptimal nonsense" of first stage like this:

Instead of arguing that the four strap ons are carring the dead weight of the core for few more deconds, I feel the rocket is not allowed to accelerate beyond certain limits. This could be to limit the aerodynamic force or something else or a combination of all. Adding few more tons of solid fuel to the core is within the reach of ISRO (the rocket is lifting off at almost 2g). It must have been done to serve a certain purpose. No point in trying to be smarter than the designers and try to teach them a point or two. It is always better to try and find out why certain things are like that, istead of saying "I know better than them". Also, making announcements in american accent is not likely to boost the thrust at any stage.


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