Indian Space Program: News & Discussion - Sept 2016

Indranil · Post by **Indranil** » 02 Sep 2016 21:37

It was from a deck of slides I had found early, but can't find them now. I think it came from Dr. B.N. Suresh, and some of the slides are captured here.

Indranil · Post by **Indranil** » 02 Sep 2016 22:15

If you can access it. There is more details here.

Main difference between that image and actual results of flight test of ATV01 are as follows:

Booster burnout: T0 + 24 secs
Ignition of sustainer: T0 + 47 secs
Dwell time attained in the M-q window is 7.4 secs (nominal is 9.2 secs) : from T0 + 64.9 secs to T0 + 72.3 secs
Burnout of sustainer: T0 + 71 secs

Ascent lasted about 63 seconds or so reaching a height of 37 kms. Total flight duration was close to 240 seconds.

I think for ATV02 the duration of burn of the booster and the sustainer and/or the coasting phase after the booster burnout was longer.

darshhan · Post by **darshhan** » 02 Sep 2016 22:40

disha wrote:No Bharath'ji - this is just a start. It has many milestones to go., for example wider dynamic range (from supersonic to hypersonic transitions)

Disha ji, Isn't this the most vexing problem? That scramjets usually light up only above Mach 3.5 and the theoretical limit for supersonic jet engines is only about Mach 3. So there is a gap which is proving to be very hard to bridge. If this gets resolved you will have your own Single stage to orbit(SSTO) vehicle.

Varoon Shekhar · Post by **Varoon Shekhar** » 02 Sep 2016 23:06

KrishG, SSSalvi or anyone, when can there realistically be a 'commercial' launch of the GSLV mark 2, with a non-Indian satellite? I do know that, after 3 successful launches, the PSLV had its first commercial launch with a German and South Korean satellite on board. Will the weight constraints of the GSLV mark 2 discourage such missions, and instead transfer the commercial launches to GSLV mark 3?

disha · Post by **disha** » 03 Sep 2016 00:18

Varoon Shekhar wrote:KrishG, SSSalvi or anyone, when can there realistically be a 'commercial' launch of the GSLV mark 2, with a non-Indian satellite? I do know that, after 3 successful launches, the PSLV had its first commercial launch with a German and South Korean satellite on board. Will the weight constraints of the GSLV mark 2 discourage such missions, and instead transfer the commercial launches to GSLV mark 3?

[since I am anyone

, KrishG is anyway AWOL - hope he is doing fine]

Varoon'ji - the next launch on 8/9/16 is F05 launch. It is no more development vehicle. So yes, Facebook can propose a sat mission to Antrix, pay in dollars and book a ride. Anyway, if they book now - they still will not get a ride till 2018/2019

So anytime soon for commercial launches will be 2020.

Did the weight "constraints" of PSLV discourage commercial missions?

PS: Why do Goras call their small raakits as 'capable' and Desis call their big raakits as 'constrained'?

disha · Post by **disha** » 03 Sep 2016 00:20

Regarding SpaceX accident:

"A small setback for SpaceX, A giant opportunity for ISRO"

dhiraj · Post by **dhiraj** » 03 Sep 2016 00:32

disha wrote:Regarding SpaceX accident:

"A small setback for SpaceX, A giant opportunity for ISRO"

Valid point, but significant capacity constraint. While ISRO focus goes for MK.3/ULV/Planet missions, till now no one to take up the ramp up of PSLV/GSLV . Don't see change till 2020

dhiraj · Post by **dhiraj** » 03 Sep 2016 00:38

So yes, Facebook can propose a sat mission to Antrix, pay in dollars and book a ride.

Amos -6 "was" 5.5 tonne.

SSridhar · Post by **SSridhar** » 03 Sep 2016 09:45

[High] Throughput communication soon for India - Madhumitha D.S., The Hindu

India is on the cusp of a satellite-driven digital or broadband revolution, similar to DTH or direct-to-home broadcasting of the 2000s, with a plan to deploy five high-throughput communication spacecraft starting this year, according to a space scientist heading the project at Indian Space Research Organisation.

These HTSs have been game-changers in the West, providing Internet connectivity many times faster, smoother, easier and probably cheaper than now. Two of the Gen-5 spacecraft are approved and getting ready; the others are said to be at various stages of consideration.

The first of them, GSAT-19, is slated for launch from India in December. It will showcase the country’s technology capability in the new area of spectrum efficiency that is trending across the globe, said P.K. Gupta, Project Director for this and GSAT-11.

“We are also considering GSAT-20 besides two next generation spacecraft HTS-1 and HTS-2 of very high capacity of 100 gbps each, which will cover the country’s total land mass,” he said.

ISRO will also test new technologies with its HTSs, such as the new flexible ‘bus’ or satellite assembly platform, electric propulsion, Ka band, lithium ion batteries, among others.

HTS reuses satellite ‘beams’ several times over smaller areas.

It will drive a next generation technology revolution. Individuals, planners in government, businesses like banks, ATMs, reservation systems, cellular and private networks and users in remote areas are expected to benefit from improved connectivity.

The West adopted the technology a few years ago With a large number of users and multiple service providers, the cost of connectivity can become affordable as in the West, he said.

disha · Post by **disha** » 03 Sep 2016 21:18

Right steps., make commercial satellite building private. That way, private companies can cater to fast moving consumer markets on their communication or commercial needs and also drive adaption of their investments. ISRO can then concentrate on building probes like MoM or Chandrayaan., and of course charge consultancy to private entities.

http://swarajyamag.com/technology/isro- ... satellites

Annadurai said ISRO plans to invite interested companies from both public and private sectors to bid for projects. The bids are intended to be appraised and a final consortium to be identified by October to ensure that the spacecraft is ready by March 2017. The second spacecraft is aimed to be ready the subsequent year.

Earlier, on 1 September, ISRO chairman A S Kiran Kumar said after inaugurating the Bangalore Space Expo 2016 (BSX-2016) that the country is “significantly” short of capacity in space and there is a need to double the number of satellites.

vina · Post by **vina** » 03 Sep 2016 21:27

Pah. It is impossible to look at ISRO's GSVL programs both MK1/MkII and also MKIII and not to feel acutely disappointed . Now MK1/2 is an Ariane 4 class rocket (same Vikas /WeakAss engines in both vehicles), but where the Ariane 4 and the Chinese Long March series clustered 4 WeaAsses in the core, and put booster rockets on the side (and hence burning a higher Isp liquid engine for longer and doing efficient staging of the booster stages), and hence putting 5tons to GTO (in the heaviest Ariane 4 ).

Now GSLV Mk1/2 made a fatal flaw of putting 4 WeakAsses as boosters , and the PSLV's solid core as core,net result, the sold core burns out a FULL MINUTE earlier than the 4 WeakAsses , and since it is in the core, the vehicle is unable to drop the spent stage, and the 4 WakAsses huff and puff carrying a deadweight of close to 3 or 4 tons (the core stage casing and motor and nozzle) and net result we have an inefficient launch vehicle overall with a GTO of 2.5 tons , which is HALF of the Ariane 4 which has comparable technology (in fact the cryogenic stage in the GSLV 1/2 has better performance than the Ariane 4's because it is a staged combustion cycle).

Just what were the guys who came up with this GSLV 1/2 configuration and putting the 4 WeakAsses in the core and the board that signed off on this to have the vehcile carry some serious amount of deadweight for a full minute must have their heads examined.

And coming to the GSVL III. It has a take off thrust of close to 10,000 KN (ie 100 ton force / 10 MN), and it clusters TWO WeakAsses in the core, and puts a piddling 4 TON (same as the Ariane 4 to GTO) . In short, what the GSLV MK1/2 should do if designed properly , the MKIII does EVEN MORE INEFFICIENTLY (take off mass of GSLV MKIII is 640 Tons, while the heaviest Ariane 4 is 470 tons) . Frankly the current config of GSLV MKIII is total Kakkoose.

Compare that to Atlas V. The base version is a 4000 KN (40 Ton force / 4MN) take off thrust, with a 2nd stage of 100 KN cryogenic stage, and a take off weight of 334 TONS , and puts about 5 Tons to GTO! Now consider that the cryogenic stage of the GSLV III is a 200 KN stage!.

All , in all, ISRO desperately needs to get rid of the WeakAss engines and the grossly inefficient solids and put in a 2 MN engine with a long burn time as the core for the GSLV Mk1/2 and get the payload to GTO to 5 Tons for that in the heaviest versions like in Ariane 4 and then put in a clustered 2* 2MN (4 MN) of that as the core in the GSLV MkIII and get the payload to 7.5 to 10 Tons GTO in the heaviest versions.

This is the only hope that ISRO has to have a launch vehicles that can be commercially competitive in the global market. I simply cannot understand why when the put in the effort to cluster 2 WeakAsses for the GSLV MK3, they didnt just cluster 4 of those like Ariane did and make both the GSLV MK1/2 and also GSLV MK3 more efficient by getting rid of the flawed architecture in the GSLV MK1/2 and buring a higher Isp liquid for a longer duration and in that case, they need not have developed the S200 at all, and just have lit the 4 clustered WeaAsses on the ground with two PSLV cores as boosters!.

The sooner they get the Kerosene /LOX (I hope a 2 MN rated engine ) into service ASAP and get rid of the compromised legacy garbage for the lower stages, the better.

disha · Post by **disha** » 03 Sep 2016 22:27

dhiraj wrote:Amos -6 "was" 5.5 tonne.

Exactly., instead of going up in space it went up in smoke. BTW, it was not a 'Facebook' satellite., but Facebook and Eutelsat decided to jointly lease 36 Ka-band spot beams. And the satellite carried other comm payloads as well.

Let us say roughly., that a half capacity satellite weighs 2/3rds that is 3.6 tonnes. That is within GSAT-Mk III capability. Or say Facebook/Eutelsat wanted a dedicated satellite with a smaller capacity (using the original AMOS platform) - the weight would be @2.2 tonnes well within GSLV - Mk II capacity. the original AMOS is a proven platform.

So for the customer, the question does come - do we go for reliability at the cost of capacity or capacity at the cost of reliability? Do we partner with others to reduce cost on a new platform or do we go all alone on a proven platform? With one blow up., face book's plans for internet.org is pretty much in smoke for 2-3 years. This will give companies like google or amazon a break to get into face book's turf of whatever it was planning too. From a business perspective this is important and leads to all sorts of cliches like "a bird in hand is better than two in bush" etc. I am sure that Mian Musk must be getting angry messages on his Facebook page from Eutelsat

Very roughly put: Part of the sat capacity is driven by the power bus and that means a concomitant increase in power generation capabilities (solar panels/power housing etc) which increases weight. For example AMOS original platform produced @1.7 KW of power while AMOS-6 was aiming for 10 KW of power! Also there is the 'commercially useless' weight of orbit raising & maintenance propellants (take it like say 50-60% of the total satellite). Again see the weight gain from 2.2 tonnes to 6 tonnes for Amos-6! Next generation AMOS-E is aiming for ion propulsion for orbit raising and orbit maintenance and bringing back the weight to 2 tonnes!!
http://www.iai.co.il/2013/34941-en/Grou ... lites.aspx

Point is., there is a move towards larger payload capacity rockets to reduce total launch costs and at the same time there is an equal move towards lighter satellites using ion propulsion etc. Further space is still unexploited or being rapidly exploited (some 1500 com/non-com sats will be launched over next 10 years., that is 150 a year or approx. 1 every 2-3 days!). Now fewer of this satellites are very-heavy or extra-heavy GSOs. With ion-propulsion., a similar capacity satellite may end up weighing <2 tonnes!! Now with reduced weight in propellant mass., a more usable mass (say a larger solar panel) can be crammed in to increase the power (why stop at 10 KW, why not go to 20 KW?) for increased capacity (why fight for 36 ka-band when 72 are available?)

So to take a current generation satellite (like Amos-6 with ion propulsion for orbit maintenance and chemical propulsion for orbit raising) and projecting on a future payload capacity is a complex exercise. In 2-3 years., ion propulsion will enter into mainstream reducing weight of the satellite and at the same time requirement of larger capacity satellites will increase its weight. At the same time, increase in payload capacity means a rocket can launch a smaller satellite directly into GSO (for example PSLV can launch a sat in GTO but GSLV-Mk II can launch the same sat into GSO) or two-three satellites into GTO/GSO (GSLV-Mk III).

If one looks at GSLV-Mk II schedule, it is already booked till 2018. So is Arianne (at the other end of the spectrum as an example). SpaceX is now out of business till 2017 (they lost their launch pad itself!). So how does one project where to put her rupees? On building bigger rockets or building more capacity to launch rockets faster (multiple launch pads and associated infrastructure)? Of course every launch has to be reliable., since one does not want to miss the bus and wait another 1-2 years.

I think the future will be driven by three parameters: Launch Cost, Reliability and Availability. And it is for both Satellite and Rockets.

That is, a very big rocket or a giant satellite is useless if it fails in any of the above parameter. What is the point in launching a big bad ass futuristic GSLV-Mk VI once in 2 years if it is either very costly compared to say GSLV-MK II or is less reliable? If launch costs are cheaper, one can also launch more scientific payloads!

ISRO in my opinion is currently correctly focused. From whatever interviews I could gather, they are focused on launch cost, availability and of course reliability.

disha · Post by **disha** » 03 Sep 2016 22:32

I find it funny when people pull out their tools for comparison and feel acutely disappointed. Again it is not the size that matters but reliability, availability and launch costs!

I am talking about rockets and nothing else. Clarifying in case other gets wrong ideas.

dhiraj · Post by **dhiraj** » 03 Sep 2016 23:49

vina wrote:I simply cannot understand why when the put in the effort to cluster 2 WeakAsses for the GSLV MK3, they didnt just cluster 4 of those like Ariane did and make both the GSLV MK1/2 and also GSLV MK3 more efficient

GSLV cryo program was being discussed starting 1983 when the first ASLV was not launched. GSLV was approved in 1990 when even the first PSLV was not launch.Insat 2A launched in 1992 was ~2 tonne which was fine for GSLV capacity and what better way to quickly develop GTO capactiy by reusing PSLV base and a Soviet Cryo.Now after that whatever mess happened to this understanding is well documented.
Hopefully we have a 65 m, 2*S250 SRBs, 2 MN Semi - cryo core , 2* C-25 vehicle with 10 tonne GTO capacity within next 10 yr feasible...

http://www.business-standard.com/articl ... 575_1.html

disha wrote:I think the future will be driven by three parameters: Launch Cost, Reliability and Availability. And it is for both Satellite and Rockets.

Problem currently is "Availability". While after every recent launch we hear ISRO leader's requesting Industries to increase capacity, while Pvt. Industry
is more focussed on the bottomline. Below two are good read (first one specially)
http://forbesindia.com/printcontent/34145
http://indiatoday.intoday.in/story/mars ... 92958.html

Another interesting read on the initial days about ISRO and Godrej tie-up
http://www.godrejappliances.com/godrej/ ... i_next.htm

disha · Post by **disha** » 04 Sep 2016 01:18

^^ Reliability? Not important?

SpaceX blew up - let us see how many will line up now to launch their precious multi-million dollars sats via them immediately? Heck they even lost the launch pad.

There is a correlation between reliability and availability. In layman terms right now, spacex is unavailable because their pre-launch operations are not reliable. Proof - the poof that just happened.

Coming to launch costs., if the launch costs are low, it broadens the base and widens the application and drives further innovation. Classic example is move from mainframes to laptops to data centers to distributed computing to new innovations like block chain (see the thread on that!)...

Just to point out- in a complex scenario - we do not have the luxury to pick a point say "availability" and debate over it while ignoring costs and reliability which are all correlated with each other.

There is an entire body of work that derives mathematical equations for reliability and availability. For example: http://www.eventhelix.com/RealtimeMantr ... 8sn6ldl2lI

Of course inputs for space vehicles is going to be different and more complex than reliability/availability calculations for transducers.

disha · Post by **disha** » 04 Sep 2016 01:38

dhiraj wrote:Hopefully we have a 65 m, 2*S250 SRBs, 2 MN Semi - cryo core , 2* C-25 vehicle with 10 tonne GTO capacity within next 10 yr feasible...

http://www.business-standard.com/articl ... 575_1.html

And what will we do with such a monstrosity for commercial applications? Just curious.

--

I think ISRO is investigating Semi-Cryo for the reason to get out of the extremely toxic UDMH/HNO4 for lower stages. And that is a good reason., but by itself there is no need to cutover to semi-cryo.

As for Solid boosters, they are not going to go away. In fact, newer solid rocket boosters (based on HMX/CL20) are bringing ISPs closer to semi-cry based motors at fraction of the cost and high reliability and at the same time providing gigantic thrust capabilities!

So just do not count solid boosters out. Just ~~google~~ altavista on solid rocket booster programs of NASA/ESA/China

dhiraj · Post by **dhiraj** » 04 Sep 2016 11:34

https://www.youtube.com/watch?v=iHgn5m139uA

"Launch Vehicles and Space Propulsion - Perspective and Trends" by S. Somanath (Director, LPSC)

https://www.youtube.com/watch?v=VJwKpYc4bpI
Dr.S V Sharma(Deputy Director, ISAC) : overview of future satellite programmes of ISAC and schedules

Neshant · Post by **Neshant** » 04 Sep 2016 13:08

vina · Post by **vina** » 05 Sep 2016 16:56

dhiraj wrote:GSLV cryo program was being discussed starting 1983 when the first ASLV was not launched. GSLV was approved in 1990 when even the first PSLV was not launch.Insat 2A launched in 1992 was ~2 tonne which was fine for GSLV capacity and what better way to quickly develop GTO capactiy by reusing PSLV base and a Soviet Cryo.Now after that whatever mess happened to this understanding is well documented.

Yes, I understand History and all that. But the point is, WHEN ISRO made the effort to cluster the WeakAsses for GSLV MKIII, they clustered 2 of those, when they could have put the same effort and clustered FOUR and in the process fixed the terrible design flaw in MK1/2 as well as made MKIII/LVM3 more efficient. It is inexplicable, they put in the effort and engineered a half assed solution and in the process, got a GSLV MKIII/LVM3 that is EVEN MORE inefficient thanks to burning vast amounts of low Isp solid.

dhiraj wrote:https://www.youtube.com/watch?v=iHgn5m139uA
"Launch Vehicles and Space Propulsion - Perspective and Trends" by S. Somanath (Director, LPSC)

Thanks for posting this. And , it is gratifying to note that ISRO has plans to put the Kerosene-LOX engine into the LVM3 and also cluster the Kerosene/LOX. Also, note the part of the speech where he talks about liquid fuels bringing down take off mass significantly , and how they are going for modular vehicles and they will have a range of vehicle configs from 1T to 10T by mixing and matching components.

And more gratifying is the fact that they are pushing for a LCH4/LOX stage and are putting up a 10ton test engine. Yup. Gradually move from Kerosene to LCH4 once you have played around with the test engine and got enough practical experience to push it.

However, I think rather than building and proving a stage with just a single Kerosene/LOX engine of 2MN, ISRO would be better off not putting effort into that and put the effort into realizing a 2* 2MN, is a 4MN clustered stage for the LVM3. That would give it a Atlas V class and highly competitive vehicle right away!

"Zimble only" like they would say at VSSC with all the Mallus around. Take the basic architecture of the L110 stage , lengthen it to put in more Kerosene and LOX ,and replace the WeakAsses in the L110 with the semi cryogenic one. You can get Atlas V like 2 stage to orbit, highly efficient vehicle, in less than 3 years.

Prem · Post by **Prem** » 06 Sep 2016 08:27

India's @isro #GSLVF5 carrying the #Insat3DR comsat is now on the pad awaiting its Sep. 8 launch

prasannasimha · Post by **prasannasimha** » 06 Sep 2016 09:35

L110 cannot just be "converted " into a semicryogenic stage. If it was that simple all countries would have such rockets. East to say but since some people have all solutions they should join ISRO and solve all their problems isn't it

JayS · Post by **JayS** » 06 Sep 2016 12:23

@Vina

I am wondering, all this solid vs liquid propulsion thing is such no brainer, even a jingo with some reading on propulsion could get this idea easily, one doesn't need to be rocket scientist. Then why ISRO with all those smart brains didn't see this thing?? They must have had a good reason why they did what they did, I presume. So what's the reason they went for solid propulsion?? I don't think the reason is they were too stupid to see this obvious thing.

adityadange · Post by **adityadange** » 06 Sep 2016 15:58

Prem wrote:India's @isro #GSLVF5 carrying the #Insat3DR comsat is now on the pad awaiting its Sep. 8 launch

Looks mighty

dhiraj · Post by **dhiraj** » 06 Sep 2016 20:28

my understanding is that if ISRO had figured out that the first local cryo would fly only by 2010 then probably they would have had a different GSLV config.in the first place. L 110 is again a stop gap approach.
Further please check the kind of focus launch vehicle's / propulsion's received in the 90's vis-a-vis last 10 years.
In the presentation by S. Somanath in the link shared earlier, he talked about semi-cryo, semi-cryo cluster, CH4-LOX engines all within next 10 year time frame.

vina · Post by **vina** » 06 Sep 2016 21:20

prasannasimha wrote:L110 cannot just be "converted " into a semicryogenic stage.

Look at the figure below and I will bet Rs 100 that they designed the L110 for just that. The total thrust that stage can bear (including the S200 is around 22MN) and it is a 4M dia stage. The kerosene/LOX will of course need insulation for the LOX tank and it's plumbing and will require that tankage stuff to be redesigned etc, but the architecture otherwise will be similar, that is two separate engines with their own pumps and turbines (unlike common pump and turbine, with two nozzles like the RD180, hence a little bit less efficient and more points of failure than the RD180, but acceptable I guess, and you can also realise a single 2M stage without clustering for PSLV)

This link has details of the config along with this diagram.

The only beef I have with this is, they should just replace the 2 WeakAsses by 2 SCE 200 and not by ONE as they seem to be planning to do. In that case, they probably will not need the S200 except for the heaviest 10 ton lift vehicle and will not need to develop the SC250 and the entire launcher series will be more efficient.

vina · Post by **vina** » 06 Sep 2016 21:25

JayS wrote:@Vina
They must have had a good reason why they did what they did, I presume.

I think Dhiraj viewtopic.php?f=3&t=6652&p=2041825#p2041812 has the answer. Launchers were pretty low down the list of priorities and they really never thought of this as a globally competitive export oriented industry until very recently.

Indranil · Post by **Indranil** » 06 Sep 2016 22:16

The antariksh-space blog has a new post (after two years).

As regards heavy-lift vehicles, we are in the process of discussion. It will be a TSTO vehicle whose first stage, like SpaceX’s, will be a five-engine semi-cryo cluster. This will have a modular structure. With one core semi-cryo stage, we can simply go on adding any number of strap-ons, and different payload requirements can be met. The second stage will be a cryo-stage. After the first stage is separated, it can be recovered in sea, like SpaceX has done.

Dr. Sivan, Director, VSSC

JayS · Post by **JayS** » 06 Sep 2016 23:33

vina wrote: I think Dhiraj viewtopic.php?f=3&t=6652&p=2041825#p2041812 has the answer. Launchers were pretty low down the list of priorities and they really never thought of this as a globally competitive export oriented industry until very recently.

dhiraj wrote:my understanding is that if ISRO had figured out that the first local cryo would fly only by 2010 then probably they would have had a different GSLV config.in the first place. L 110 is again a stop gap approach.
Further please check the kind of focus launch vehicle's / propulsion's received in the 90's vis-a-vis last 10 years.
In the presentation by S. Somanath in the link shared earlier, he talked about semi-cryo, semi-cryo cluster, CH4-LOX engines all within next 10 year time frame.

Hmm. That seems like a reasonable explanation. But is that the whole story?? What about other factors such as lack of funds, technical challenges etc??

Indranil · Post by **Indranil** » 07 Sep 2016 03:41

ISRO has its eyes firmly set on a core stage powered by multiple SCE-200 engines. Many of their speakers have expressed this by now. However, their hands are tied with shoestring budgets.

As new technologies become available, they are incorporating them into their launch vehicles. First, they build up confidence of building a stage powered by a single Vikas engine. Once they got that, they put together a stage with multiple Vikas engines.

In parallel, they are designing the SCE-200. Once the SCE-200s comes onboard, I can't imagine the Vikas engines being used again. I had read somewhere that they build the engine, but did not have the budget for necessary test facilities. They had to go through the Ukrainians to get the Russian test stands. Once they build up confidence in designing a stage with a single SCE-200 engine, they will surely look at building a stage with multiple SCE-200s.

I wonder, if it will also be useful to design a reusable booster powered with a SCE-200.

prasannasimha · Post by **prasannasimha** » 07 Sep 2016 07:53

Every stage of development was done with existing facilities and shoe string budget. Easy to decry them but just imagine the amount of effort they had to put and even direct sabotage that was done to their plans. Actually each modification has been well thought and with a reason given the circumstances they were dealing with.

prasannasimha · Post by **prasannasimha** » 07 Sep 2016 07:58

http://www.isro.gov.in/update/05-sep-20 ... d-lab-have

Sep 05, 2016
Mission Readiness Review (MRR) committee and Launch Authorization Board (LAB) have cleared the 29 hr countdown starting at 11.10 hr IST on Wednsday, September 7, 2016 and the launch of GSLV-F05/INSAT-3DR Mission for Thursday, September 8, 2016 at 16.10 hr

vina · Post by **vina** » 07 Sep 2016 08:21

indranilroy wrote:They had to go through the Ukrainians to get the Russian test stands. Once they build up confidence in designing a stage with a single SCE-200 engine, they will surely look at building a stage with multiple SCE-200s. .

ISRO signed an agreement with the Russians to use their Kerosene /LOX test stands until ISRO's own facilities come up at Mahendragiri.
They already have experience in clustering from L110. There is no need to to build a single engine stage and then cluster it. They are not going to share turbo machinery like the Russian engines, but rather individual whole engines that share common propellant and oxidiser tanks!

symontk · Post by **symontk** » 07 Sep 2016 09:52

ISRO doesnt have experience in clustering of engines (in a signle frame) at ground level although PSLV's PS4 is there, it is for high altitude. L110 is to experiment there, once done, they will move with more clusters. 30 years back they were looking at 4 engine cluster of Vikas, must have changed with priorities

juvva · Post by **juvva** » 07 Sep 2016 11:40

vina wrote:
JayS wrote:@Vina
They must have had a good reason why they did what they did, I presume.
I think Dhiraj viewtopic.php?f=3&t=6652&p=2041825#p2041812 has the answer. Launchers were pretty low down the list of priorities and they really never thought of this as a globally competitive export oriented industry until very recently.

My "feeling" is that India, decided to develop the solids first for strategic reasons. This seems to have worked well, as DRDO did leverage the technology in the initial stages of IGMDP.

juvva · Post by **juvva** » 07 Sep 2016 12:07

Countdown started (ISRO website):

Sep 07, 2016 The 29 hr countdown operation of GSLV-F05/INSAT-3DR Mission has started at 11:10 hr IST on Wednesday, September 7, 2016

update:

Sep 07, 2016 Second stage (GS2) N2O4 filling under progress
Sep 07, 2016 Preparations for Second stage (GS2) propellant filling operation are under progress

SSridhar · Post by **SSridhar** » 07 Sep 2016 14:33

juvva wrote:My "feeling" is that India, decided to develop the solids first for strategic reasons. This seems to have worked well, as DRDO did leverage the technology in the initial stages of IGMDP.

juvva, from the beginning, GoI has been very clear about keeping the space & missile/military projects separate. Besides, the very first IGMDP missile was the single stage, twin engined and liquid-propelled Prithvi-1. Even the naval-variant Dhanush were liquid-engined.

IMO, the partiality to solid propellants was because of historical reasons. We can get a fair idea from Gopal Raj's book, "Reaching for Stars". We started with NASA-supplied Nike-Apache from Thumba. These were all solid-propelled. These were followed by the French Centaure which were also solid propelled. The French seem to have helped in setting up the fabrication facilities for Centaure including a solid propellant plant. In some indigenous Rohini sounding rockets, even cordite sourced from the Cordite Factory at Ooty was used. When SLV-3 was designed, no facility existed for making liquid propellants.

To quote from Gopal Raj, "An additional factor for using solid engines may have been Prof. Hideo Itokawa of the Institute of Space & aeronautical Sciences in Japan, whom Sarabhai had appointed as a consultant. The Japanese had orbited their first satellite, the 23 Kg Osumi in early 1970 using the Lambda-4s Launcher which had four solid stages as well as two solid strap-on motors. Since the technologically more advanced Japanese had opted for the solid route, it would have reinforced opinion in India that was the way to go

More importantly, the Indians had in mind a launcher on which they could model their own launch vehicle - the Scout developed by the US. An acronym for Solid Controlled Orbital Utility system, the Scout was an all-solid 4-stage vehicle intended as a low-cost launcher. . .Since the Scout had successfully flown, the Indian scientists could be confident that a four-stage wholly solid launch vehicle of this sort was definitely feasible. . . By the end of the SLV-3 programme, ISRO had first-rate capability in all aspects of solid propulsion."

rsingh · Post by **rsingh** » 07 Sep 2016 19:45

I think India has most wheather satellites. Why we need those. Sidha-sidha qyon nahi bolte that these sats are to count numbers pf noddles in chinese fauji's bowl.

Bheeshma · Post by **Bheeshma** » 07 Sep 2016 22:09

You mean the IRS series? INSAT-3DR from 36000 km can't see the bowl let alone the noodles.

shravanp · Post by **shravanp** » 07 Sep 2016 22:30

I hope the launch video cameras have evolved and do good job tomorrow. It's utterly disappointing to see smoke shadows whereas rocket as zoomed way past.

Indranil · Post by **Indranil** » 07 Sep 2016 23:56

vina wrote:
indranilroy wrote:They had to go through the Ukrainians to get the Russian test stands. Once they build up confidence in designing a stage with a single SCE-200 engine, they will surely look at building a stage with multiple SCE-200s. .
ISRO signed an agreement with the Russians to use their Kerosene /LOX test stands until ISRO's own facilities come up at Mahendragiri.
They already have experience in clustering from L110. There is no need to to build a single engine stage and then cluster it. They are not going to share turbo machinery like the Russian engines, but rather individual whole engines that share common propellant and oxidiser tanks!

To a layman, I can think of three main changes between the SCE200 cluster and the Vikas cluster on the L110.
1. Rate of consumption of propellant/oxidizer by the SCE200 will be significantly higher than that of the Vikas engine.
2. The tanks themselves will have different dimensions. One of them will be further.
3. The fuel/oxidizer themselves are different.

In lieu of the above, and others that I don't know of, can the L110 clustering system be adopted as is or with minor changes to cluster two SCE2000s?