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Indian Space Programme Discussion - Sept 2016

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Re: Indian Space Programme Discussion - Sept 2016

Postby gakakkad » 02 Jun 2017 21:03

Gagan wrote:ISRO was a big customer for Arianespace. ISRO had 1-2 launches every year, for the last 10-15 years.
That will be a fairly big loss for Ariane space.


That in itself would be quite a loss .+ Isro taking away atleast some of the customers of Arianne space.

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Re: Indian Space Programme Discussion - Sept 2016

Postby nirav » 02 Jun 2017 21:12

Indeed.
If however in the next few years, we need to launch heavier sats to GTO and if our launchers are not ready, there's no harm going back to arianespace.

The 10ton to GTO is not an urgent need for the moment.
It will be done however in due course of time.

The discussion in ISP and lugging dead weight keeps coming up regularly in this thread.

I'd just like to say, if ordinary jingoes like us know about the advantages/disadvantages of them,it's beyond doubt that the people@ ISRO who design and build and launch these rockets are aware of them.

That they still choose to stick to a low ISP solid,Vikas engines non clustered by 4 or carry dead weight is a decision taken after extensive deliberations keeping in mind all of ISROs strengths and weaknesses and pros and cons of the approach.

Spreadsheet rocketry is not really a serious thing.

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Re: Indian Space Programme Discussion - Sept 2016

Postby Singha » 02 Jun 2017 21:42

Best of best doing 2% of mass to gto shows how pathetic the current method is. Would anyone accept a power plant or car that bad..

I wonder if the paul allen stratolifter or rockets that use atmospheric o2 as the climb will do better?

Perhaps a massive emals that hurls the 2nd stage and payload some 50 miles up where upper cryo ignites and takes it into gto? Do away with 1st stage circus and hence 80% of the weight. But initial launch acceleration will be frightening. Not human rated for sure.

How about a lego brick type 1st stage that is 10 sub stages? Each 2.5 meter section with composite body burns up and drops off...efficiently shedding weight. We could build a pralay ER missile out of this idea ... 500kg of heat at 500km cheaply

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Re: Indian Space Programme Discussion - Sept 2016

Postby Vivek K » 02 Jun 2017 22:02

Come Singha ji - i wouldn't call it pathetic. ISRO is the only Indian PSU that actually is at the cutting edge of technology by its own initiative. Now that the aerodynamics and baseline efficiencies are established they can incrementally take risks with improving yields/efficiencies.

At the end of the day, they must be doing OK with the commercial aspect (i.e. revenues > cost). So the situation needs improvement but the accomplishments are still path breaking - journey to the Moon, Mars and 30+ flawless launches of the PSLV. Not a mean feat by any standards.

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Re: Indian Space Programme Discussion - Sept 2016

Postby nirav » 02 Jun 2017 22:11

Singha ji,
What you propose is certainly doable in probably the next century. If now, in our sleep.dreams can go anywhere do anything.

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Re: Indian Space Programme Discussion - Sept 2016

Postby gakakkad » 02 Jun 2017 22:12

Singha wrote:Best of best doing 2% of mass to gto shows how pathetic the current method is. Would anyone accept a power plant or car that bad..

I wonder if the paul allen stratolifter or rockets that use atmospheric o2 as the climb will do better?

Perhaps a massive emals that hurls the 2nd stage and payload some 50 miles up where upper cryo ignites and takes it into gto? Do away with 1st stage circus and hence 80% of the weight. But initial launch acceleration will be frightening. Not human rated for sure.

How about a lego brick type 1st stage that is 10 sub stages? Each 2.5 meter section with composite body burns up and drops off...efficiently shedding weight. We could build a pralay ER missile out of this idea ... 500kg of heat at 500km cheaply


That is a physical limitation of the current rocket design....Its a "physical limitation" of rockets ... Ariane 5 weighs 777 tons...they carry a payload of 6 ton to 10 ton to GTO..An "effeciency" of 1% to 1.6 %,,, as they LV gets heavier the effieciecy is bound to go down... a problem caused by the "variable mass problem"..

one of the reason why one needs to alternative systems...

A lego like 10 stage design may increase some efficiency ... but not by much...

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Re: Indian Space Programme Discussion - Sept 2016

Postby Sridhar » 02 Jun 2017 23:28

ldev wrote:Below is a listing of current and some proposed launch vehicles from around the world. All figures sourced from Wikipedia. Gives some idea about the efficiency of various designs in lofting payloads to GTO:

Ariane 5 esa
Mass at lift off tons 777
Payload to GTO tons 10.5
2 stage
Payload to GTO/Mass at Liftoff 1.35%

Delta 4 heavy
Mass at lift off tons 733
Payload to GTO tons 14.2
2 stage
Payload to GTO/Mass at Liftoff 1.94%

Long March 5
Mass at lift off tons 879
Payload to GTO tons 14.0
2 stage
Payload to GTO/Mass at Liftoff 1.59%

Proton M
Mass at Liftoff tons 705
Payload to GTO tons 6.3
3 stage
Payload to GTO/Mass at Liftoff 0.89%

Falcon 9
Mass at Liftoff tons 549
Payload to GTO tons 8.3
2 stage
Payload to GTO/Mass at Liftoff 1.51%

Falcon heavy - first flight expected July-Sep
Mass at Liftoff tons 1421
Payload to GTO tons 26.7
2 stage
Payload to GTO/Mass at Liftoff 1.88%

GSLV Mk 3
Mass at Liftoff tons 640
Payload to GTO tons 4.0
3 stage
Payload to GTO/Mass at Liftoff 0.63%


This is an interesting comparison, but one has to be cautious since these different vehicles are launched from launch sites that differ in how ideal they are for GTO launches. Sriharikota is not as great as Kourou (Arianespace) but much better than many of the other launch sites. Also, the different launchers are at different stages of evolution.

Another good comparison would be cost per kg for the launch across these launchers. Some designs are heavier but also cheaper - in terms of fuel cost, handling costs etc. Even leaving aside the widely different development costs (and these are very hard to reliably compute in any case), I would think there is a wide range in costs across these launchers.

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Re: Indian Space Programme Discussion - Sept 2016

Postby Gagan » 03 Jun 2017 00:03

Again, cost/kg as rightly pointed out, will depend on the latitude of the launch site

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Re: Indian Space Programme Discussion - Sept 2016

Postby gakakkad » 03 Jun 2017 00:18

Cost/kg would not necessarily be the best comparison due to differences in the economy... Things are always going to be cheaper in India than elsewhere..

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Re: Indian Space Programme Discussion - Sept 2016

Postby Prithwiraj » 03 Jun 2017 00:30

ISRO has amazing stuff with very limited budget compared to other space agencies. However I hope we don't sacrifice innovation and efficiency using low labor cost as an arbitrage like what we have done for IT

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Re: Indian Space Programme Discussion - Sept 2016

Postby Atmavik » 03 Jun 2017 00:33

nirav wrote:Singha ji,
What you propose is certainly doable in probably the next century. If now, in our sleep.dreams can go anywhere do anything.


There is the space elevator or the space gun. I am sure the digagh's of this dhaga know abt Gerald bull.

While we dream ISRO is building rockets step by step. I am a fan of there project management

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Re: Indian Space Programme Discussion - Sept 2016

Postby gakakkad » 03 Jun 2017 01:27

i think we should consider spending more on isro... The budget seems to be capped to 1 billion for quite a few years...its time to at least double it... A space station+ manned space flight mission would have many many off sets...+ the publicity it would bring would help Antrix getting even more commerical contracts....we need many more start ups like team indus..if space station and manned missions go well we ll get more startups and more private money in space business.. If more money is spent we can definitely have the unified launch vehicle and the semi-cryo earlier...

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Re: Indian Space Programme Discussion - Sept 2016

Postby Singha » 03 Jun 2017 01:31

Arthur clarke had space elevator in
One of his books

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Re: Indian Space Programme Discussion - Sept 2016

Postby Bheeshma » 03 Jun 2017 02:01

ISRO's budget is 1.4 billion USD. I hope it will be soon be 2 billion (in 3-4 yrs).

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Re: Indian Space Programme Discussion - Sept 2016

Postby nirav » 03 Jun 2017 03:29

@ The 10 ton to GTO and having capability to launch foreign heavy sats,
it occurred to me .. Americans will launch their heavy satellites with their own launchers.So will Russians,Chinese,Europeans and the Japs(eventually).

We will launch our own.

Its mostly a captive and a well controlled market.

Its often said satellite launch business is a multi billion dollar industry. well, where are the big billions ?

This is a report on Arianespace posting a net profit of a paltry 4 million euros on a 1.433 Billion turnover. They've had their big rockets for a while.whats the point of an uber high ISP and launch config if at the end of the day money wise they make pennies on the dollar ?
http://www.arianespace.com/press-releas ... er-family/

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Re: Indian Space Programme Discussion - Sept 2016

Postby gakakkad » 03 Jun 2017 03:40

India will have a massive domestic market ... And Africa is growing..so there will be demand.

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Re: Indian Space Programme Discussion - Sept 2016

Postby Bheeshma » 03 Jun 2017 03:56

South east asia, middle east and Latin america too.

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Re: Indian Space Programme Discussion - Sept 2016

Postby ldev » 03 Jun 2017 06:11

SpaceX, the leader in low cost launches charges $62 million per launch for a full payload on the Falcon 9. If 8.3 tons is launched to GTO as an ultra heavy communications satellite e.g. the cost is $ 7470/kg. This is without passing on any cost savings because of first stage & payload fairing reuse as it's still a work in process.

The GSLV Mk 2 in comparison (figures again from Wiki) can launch 2.5 tons to GTO and costs Rs 220 crores ($ 36 million) per launch. That works out to $14,400/kg. I doubt whether the GLSV Mk 3 cost/kg will be significantly different.

As far as each country being treated as a silo for launch business, because costs were not significantly different across launchers, launch customers gravitated towards a homegrown solution. (Also there is some protection in the business undoubtedly). But if as Musk says that costs can be reduced by as much as 75% with only first stage and payload fairing reuse, then SpaceX has a significant ability to be flexible on pricing and attract customers currently using other launchers.

ISRO should work on the RLV which they have been talking about, it's the only way to reduce launch costs. Space launch EMAL etc. maybe after 50-80 years.
Last edited by ldev on 03 Jun 2017 06:16, edited 1 time in total.

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Re: Indian Space Programme Discussion - Sept 2016

Postby Gagan » 03 Jun 2017 06:16

India's advantage will be cost of launch + the ability to offer a custom built satellite for various nations.
Antrix needs to aggressively market GSATs + Launch from Sriharikota now
For this:
1. Need a runway at sriharikota
2. Commercialize / privatize component manufacture of both sats and launchers
3. Inventory build up of components and satellite bodies and bulk orders being placed

As it is, there is an ever increasing shortfall of transponders in india. It is a bit like the navy's sub force, declining numbers and future obsolence in the face of increased demand.
ISRO has to increase the frequency of its GSLV launches

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Re: Indian Space Programme Discussion - Sept 2016

Postby vina » 03 Jun 2017 07:14

ldev wrote:SpaceX, the leader in low cost launches charges $62 million per launch for a full payload on the Falcon 9. If 8.3 tons is launched to GTO as an ultra heavy communications satellite e.g. the cost is $ 7470/kg. This is without passing on any cost savings because of first stage & payload fairing reuse as it's still a work in process.

The GSLV Mk 2 in comparison (figures again from Wiki) can launch 2.5 tons to GTO and costs Rs 220 crores ($ 36 million) per launch. That works out to $14,400/kg. I doubt whether the GLSV Mk 3 cost/kg will be significantly different.

Yes. FINALLY SOMEONE who actually posts numbers instead of "I think" and "I feel" .

So, why is Space X launches significantly cheaper than the GSLV MK2 , more so when wages and other costs are far higher in the US ? And how is it that in India, despite whipping the ISRO folks hard and feeding them "poo", the GSLV Mk2 ends up being more expensive than the Falcon ?

Answers .
1. Open, any standard book /google and look at "Growth Models" (Solow Growth Model is easy to understand), and you can find out that that in the long run, PRODUCTIVITY alone creates growth. Productivity --> efficiency . So more efficient you are , you create surpluses that can be shared. So that is why, despite whipping the folks in ISRO hard and feeding them "poo" , you will end up with a more expensive machine than a Space X which feeds it it's folks gruel and kicks them hard in the ass ..

2. Economies of scale kick in. Just like in a plane, ship , truck etc, the cost per ton kicks in with higher payloads due to economies of scale and the per unit cost comes down. That is why it is cheaper to launch 2 , 5 ton satellites on 1 launcher of 10 tons, instead of 5 ton on a single rocket. (same reason why the cost per seat mile in a A380 is far cheaper than in an A320. It is cheaper to fly one A380 to transport 450 passengers, than fly 4 A320s to fly the same number of people)

In the list of mass fractions posted above, what is missing is Atlas V. With the RD-180 and Centuar upper stage, it will have the highest mass fraction among everything else out there (along with Space X and LM5 ) for like to like config. Reasons are.. 1) Ariane V mass fraction and GSLV MKII & III mass fractions drop because of the use of solids.

Cheaper solids vs liquids engines holds somewhat (does it really ?) only for single use rockets. With reuse like what Space X and others are thinking of , it will tilt tremendously towards liquids, which together with their higher efficiencies will simply crush solids in long run.

Reading on the wall. Solids for space launch business is going the way of the Dodo. Solids are perfect for Missiles. Not so for space launch, particularly so if you factor in reuse, like the industry is going for.

Also, with solids, for a large launch vehicle, you absolutely NEED the vertical assembly and cost infra associated with and transporting a vertically assembled vehicle. Not so for a liquid. The empty rocket is practically weightless ,it is assembled horizontally in an el Chepo building, rolled out horizontally and then jacked up, the fuel and oxidant is pumped in and fired (Soyuz and Space X) . You need to factor those costs in as well.

Russian Engg at it's absolute best here in these two videos.

Soyuz Assembly


Soyuz Rollout


Falcon 9 Rollout

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Re: Indian Space Programme Discussion - Sept 2016

Postby disha » 03 Jun 2017 09:34

ldev wrote:The GSLV Mk 2 in comparison (figures again from Wiki) can launch 2.5 tons to GTO and costs Rs 220 crores ($ 36 million) per launch. That works out to $14,400/kg. I doubt whether the GLSV Mk 3 cost/kg will be significantly different.


Falcon class has a long history of development and further space x leases NASA launch platforms at a very throwaway prices.

More importantly it is a TSTO., and simplification and economies of scale on developing only one kind of engine and a stage using combinations of that leads to significant cost savings.

ISRO should work on the RLV which they have been talking about, it's the only way to reduce launch costs. Space launch EMAL etc. maybe after 50-80 years.


Space launch EMALs were thought off in 80s itself when high temperature superconductivity was discovered. Basically a SSTO's with electro magnets' accelerated to 4-5 Km/s and thrown up into space.

ISRO must double up on RLV., it has to spend some serious rupees there.

Using the weight of the launch assembly and using it as calculations is fraught with risks., for example the solid stage structure uses maraging steel in GSLV while the tankage in falcon is aluminium lithium alloy. A solid booster with a composite structure and with HMX propellant will give you as much or more Isp than NO4/UDMH. And a super mighty thrust. Again this is advanced area of research.

Just taking total weight of the launcher and then dividing up with operational launch cost to arrive at per kilogram cost of launch is childish.
Last edited by disha on 03 Jun 2017 10:03, edited 2 times in total.

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Re: Indian Space Programme Discussion - Sept 2016

Postby disha » 03 Jun 2017 09:49

Posters do on this forum make grand statement like horizontal assembly is "cheaper" than vertical assembly., without any numbers or facts - just to prove their supercillious point.
===
Soviet horizontal integration facilities came for a different reason and definitely not for a cost consideration.

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Re: Indian Space Programme Discussion - Sept 2016

Postby SSridhar » 03 Jun 2017 11:03

ISRO abuzz with Monday’s heavy-lift rocket launch - Madhumathi D.S., The Hindu
An anxious space establishment is keeping its fingers crossed over the launch of its new and most powerful rocket on June 5.

On that evening, the indigenous GSLV-Mark III will make a bid to breach a heavy-lift rocket club that can put four-tonne satellites into space. The U.S., Russia, Europe, China and Japan are already there.

The first development vehicle, called GSLV-MkIII D-1, is slated to fly from the Satish Dhawan Space Centre at Sriharikota at 5.28 p.m., says the Indian Space Research Organisation.

The success of the first full flight of Mk III will mean that soon, Indian communication satellites can be lofted into space from within the country. It will also improve ISRO’s ability to reach heavier satellites to both — the higher geostationary transfer orbit or GTO of 36,000 km; and to low-Earth orbit or LEO of up to 800 km. ISRO Chairman and Secretary, Department of Space, A.S. Kiran Kumar, told The Hindu : “MkIII should enable us to launch communication satellites totally in India without going out. That is the primary aim.”

“We are improving our capacity to put higher payloads into GTO and LEO. What we now have with MkII is capability for lifting 2.2 tonnes to GTO. This rocket will give us a higher weight capability than what we now have, for both GTO and LEO. Since 1995, we have launched all Earth observation satellites [which are smaller] ourselves on the [lighter lifting] PSLV rocket. Once we are through with GSLV MkIII, we will be able to launch all communication satellites ourselves.

Independence apart, an indigenous launch vehicle also means lower cost of putting spacecraft to orbit, said K. Sivan, Director of the lead rocket development centre, Vikram Sarabhai Space Centre, Thiruvananthapuram.

Larger payload soon

The first payload, communication satellite GSAT-19, however, has been kept below 4 tonnes — at a safe 3,136 kg. “We will subsequently increase the payload,” Mr. Kiran Kumar said. Communication spacecraft are generally put into GTOs first (the orbit is adjusted over days.)

Although MkIII was approved in 2002 and work on it and its facilities began over the last six to eight years, the most intensive part was during 2014-16. In December 2014, ISRO conducted a partial flight using only MkIII’s solid motor S200 and liquid stage L110, flying it to around 160 km.

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Re: Indian Space Programme Discussion - Sept 2016

Postby vina » 03 Jun 2017 12:44

Using the weight of the launch assembly and using it as calculations is fraught with risks., for example the solid stage structure uses maraging steel in GSLV while the tankage in falcon is aluminium lithium alloy.

That is like arguing that someone is "flabby" and hence will run 100m slower than person who is all muscle. That is exactly the point. You ispeako in Yindi , I isepak in Inglees.

In Inglees, what it means is that solid motors have a lower mass fraction because 1) It's structure is heavier (all the steel casing weight) and 2) The APCP propellants have a lower specific impulse than the typical liquid fuels by quite a margin (around 30s, roughly 10 to 15% less than the Kerosene/LOX)

A solid booster with a composite structure and with HMX propellant will give you as much or more Isp than NO4/UDMH. And a super mighty thrust. Again this is advanced area of research.

Ah, but I thought everyone said, solid -solid rah-rah because it is "cheap" . You start putting in composites and exotic compositions in propellant, then the cost goes sky high, so defeats the entire purpose.

Soviet horizontal integration facilities came for a different reason and definitely not for a cost consideration.

Horizontal integration is far cheaper (doesnt need the mobile assembly tower) and handling is much easier as well, because the empty rocket weighs very little .

Now horizontal installation is possible for a large rocket only if it is liquid fuelled (for a solid ,you can't do beyond an ICBM on with horizontal integration and handling.. the structure starts getting very inefficient.. think of a beam holding up 700 tons horizontally .. the structure and inter-states needs to support that) . If there are solids, you HAVE too stack it vertically. The solid stages are literally "bricks"..

Even the "largest" out there, the Delta IV "Heavy" is integrated horizontally because it is all liquid. Check this video, there is even a "Desi" looking guy doing the integration . The handling is so much easier, no fancy Mobile Assembly tower require. A bog standard hanger and some basic changu mangu tools and equipment.


Delta IV "Heavy" being jacked upright. You CAN't do this if the boosters were solid. The structure would be massively heavy if you wanted to do so.

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Re: Indian Space Programme Discussion - Sept 2016

Postby A_Gupta » 03 Jun 2017 18:07

https://thewire.in/110065/isro-gslv-falcon-ariane/
Apples and Oranges: Why ISRO Rockets Aren’t Comparable to Falcons or Arianes

Variable costs: March 13, 2017 story:
http://www.marketwatch.com/story/faa-re ... 2017-03-13
Before approving earlier this month a license authorizing launch of a Falcon 9 rocket from the Kennedy Space Center to transport an EchoStar Corp. broadcast satellite into orbit, the Federal Aviation Administration mandated at least $63 million liability coverage for government property that could be damaged by prelaunch activities. Until this year, the required coverage for such operations was $13 million.

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Re: Indian Space Programme Discussion - Sept 2016

Postby Indranil » 03 Jun 2017 19:04

Aren't we rehashing the same discussion again and again. In my opinion, both the accusations and the defense have not raised their level one bit. Fraankly, it is a bit tiring. Sorry.

Of course, lugging deadweight for any amount of time is not optimal. Don't try to defend that. Look at how ISRO has tried to optimize the GSLV Mk2. Over the years, they have progressively reduced the time for which they lug that deadweight. Of course, using liquids gives higher efficiency. Don't try to defend that! Otherwise, ISRO would have made bigger solid boosters instead of replacing L110 with the SCE200. Their TSTO would have a solid first stage. Have you see the boosters on the mega launcher? Are they solids?

On the other hand, whatever back-of-the-envelop calculations the detractors are throwing are so elementary, it took me (with any background knowledge at all) a grand total of 10 hours of reading to understand most, if not all of it. I am sure ISRO folks know this. So, a much better discussion would be why ISRO went the way they did. There will be lot more to learn about actual rocket building with actual budget and launch constraints.

ISRO learnt to crawl with PSLV/GSLV, and then walk with LVM/ULV, before running with the TSTO. If we get to a TSTO in 10 years, it would have taken us 45 years to go from sounding rockets to a TSTO. Without acquiring scientist and technology, stealing, or collaborating, it is not bad at all. Let's save these comparison of cost, mass ratio etc. with the best of the west till then.

Today, we should celebrate that we are going from crawling to walking. Go GSLV MkIII. Go!

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Re: Indian Space Programme Discussion - Sept 2016

Postby ldev » 03 Jun 2017 21:06

vina wrote:In the list of mass fractions posted above, what is missing is Atlas V. With the RD-180 and Centuar upper stage, it will have the highest mass fraction among everything else out there (along with Space X and LM5 ) for like to like config.


You are correct. The RD-180 is used as first stage of the Atlas V. And it's interesting that inspite of the ever worsening US-Russia relationship, stopping the imports of the RD-180 from Russia was the last thing the US wanted. Beats me why ISRO did not get the RD-180 from the Russkies in addition to the technology for the C25 upper stage? By now India could have developed it's own version of the RD-180 and been King of the Hill. And the RD-180 does give the Atlas V launcher the highest mass fraction of all launchers. No wonder the US does not want to give up those imports.

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Re: Indian Space Programme Discussion - Sept 2016

Postby Kakarat » 03 Jun 2017 21:50

ldev wrote:
vina wrote:In the list of mass fractions posted above, what is missing is Atlas V. With the RD-180 and Centuar upper stage, it will have the highest mass fraction among everything else out there (along with Space X and LM5 ) for like to like config.


You are correct. The RD-180 is used as first stage of the Atlas V. And it's interesting that inspite of the ever worsening US-Russia relationship, stopping the imports of the RD-180 from Russia was the last thing the US wanted. Beats me why ISRO did not get the RD-180 from the Russkies in addition to the technology for the C25 upper stage? By now India could have developed it's own version of the RD-180 and been King of the Hill. And the RD-180 does give the Atlas V launcher the highest mass fraction of all launchers. No wonder the US does not want to give up those imports.


The CE20 (C25) technology was not from the Russians its a in house development of ISRO, what we got from russians was only 7 KVD-1 technology of which was to be transferred but was denied due to USA. May be we got a few drawings under the table and developed CE7.5. But still CE7.5 is Staged combustion and CE20 Gas Generator cycle and both are different technologies. Likewise ISRO is developing its own Semi-cryo SCE-200. Not every technology/product developed by India is from Russia or others

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Re: Indian Space Programme Discussion - Sept 2016

Postby Gyan » 03 Jun 2017 22:24

Launch weight per kg is relevant but launch cost per kg is way more important.

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Re: Indian Space Programme Discussion - Sept 2016

Postby jamwal » 03 Jun 2017 23:21

Vina, can you stop using silly expressions like feeding poo ?

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Re: Indian Space Programme Discussion - Sept 2016

Postby disha » 04 Jun 2017 00:21

RD-180 was offered to US just after the immediate breakup of Soviet union., Indians did not even know that the theoretical staged combustion was actually implemented by soviets and several of such engines were stored around and not destroyed. Hence the question of RD-180 for ISRO does not even arise*.

It is not like ISRO has unlimited budget and its chief walks into the erstwhile soviet space program office and says "Kitne RD-180 hain"!

I do not understand why we are doing the rona-dhona by leaning over to the other side and asking oneself - wow they have got hold of RD-180 and if-only we had that we would have a bigger ....!

ISRO's staged-combustion CUS is completely indigenously developed. What ISRO got from Russia was 7 stages and one ground mock-up and NO TECHNOLOGY ., ISRO used the ground mockup and the 7 stages to design its own upper stage meeting the specifications of the russian stages! Interestingly ISRO's CUS is one powerful engine and can be throttled from nominal 7.5 kN to 9.3 kN. That is @20% thrust increase! Hence a larger propellant loading and a longer burn time will incrementally increase the GSLV Mk II payload.

Now coming to the design of GSLV Mk-II itself., what did ISRO have? Here is what the proven stages ISRO had (*numbers rounded off/approximated) :

1. Solid stage from PSLV - S138/S139 - Burn time @100 seconds.,
2. Liquid engines (800 kN) - Burn time @160 seconds.,

And a mandate to deliver a GTO capability of 1.5 to 2 tonnes.

How would one go about it?

Now here is an interesting nugget., the word "proven" on liquid engines is slightly shaky. If one looks at the failures of GSLV Mk-1/II., two of the failures came *directly* from its liquid engines. Of course before launch on paper., the designer had even less trust on the liquid engines.

Using items #1 and #2 above only., what would you have done?

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Re: Indian Space Programme Discussion - Sept 2016

Postby nirav » 04 Jun 2017 03:52

ldev wrote:SpaceX, the leader in low cost launches charges $62 million per launch for a full payload on the Falcon 9. If 8.3 tons is launched to GTO as an ultra heavy communications satellite e.g. the cost is $ 7470/kg. This is without passing on any cost savings because of first stage & payload fairing reuse as it's still a work in process.

The GSLV Mk 2 in comparison (figures again from Wiki) can launch 2.5 tons to GTO and costs Rs 220 crores ($ 36 million) per launch. That works out to $14,400/kg. I doubt whether the GLSV Mk 3 cost/kg will be significantly different.

As far as each country being treated as a silo for launch business, because costs were not significantly different across launchers, launch customers gravitated towards a homegrown solution. (Also there is some protection in the business undoubtedly). But if as Musk says that costs can be reduced by as much as 75% with only first stage and payload fairing reuse, then SpaceX has a significant ability to be flexible on pricing and attract customers currently using other launchers.

ISRO should work on the RLV which they have been talking about, it's the only way to reduce launch costs. Space launch EMAL etc. maybe after 50-80 years.


Idev ji,
Please go through this article.

https://www.theverge.com/2017/1/13/1426 ... -financial


https://www.fool.com/investing/general/ ... table.aspx

Gist of it almost looks like musk wanting to do a Jio on the space launch business.

One kaboom they had in 2015 on the launchpad had their year go a quarter billion dollars in the negative.

For me, whenever I visit this thread and see the 'discussion' on mass fraction and clustering,all Cryo, competition is doing this and that, ISRO underperforming and customary bah and pah being thrown at ISRO.. I think of it as a newbie coming and saying, Lockheed Martin flew Raptor in the 90s is now on the F35, stealth is uber, therefore ADA/DRDO/HAL/LCA hai hai.

June 5th is a very important date when the GSLV mk3 will be proving it's operational capability.
It's the first flight of this specific Cryo engine.

Before people throw brochure numbers, it's important to look at the time taken to realise both the cryos for the GSLV series.all these years of hard work and toil have given us this technology which will need a few more years and flights to declare reliably operational.


We still have a way to go in mass production of these launch vehicles to realise economies of scale.

@the spacex figure of 7,000 odd per kg for falcon 9 and GSLV mk2 figure of 14,000 odd per kg - an important thing to note is, GSLV cost figures are in line with ULA vehicles which don't use solids or 'lug' dead weight. Please reference the article above for spacex vs ULA costs..

I'm quoting from the article, they had a projection of 55 million operating profit on 1.8 billion revenue based on 20 launches for the year.They managed all of 8 launches.
Either ways it's just 3% operating profit on revenues.

My point is having uber mass fraction or technology isn't a guarantee of success or profitability.Also their business and what ISRO does are fundamentally different things.

One is for profit and the other is for realising technologies indigenously and achieving strategic autonomy in the space business.Antrix and its profits are a by product.

The constant Rona dhona on the thread and spread sheet rocketry solutions of 10 ton to GTO become tiresome.

It's easy to compare ISP values of solids vs cryos.
Or which configuration has best "mass fraction".
The person making the comparison and pooh pooing ISRO should make the effort to list the R&D costs involved behind those uber rockets and the paltry budgets ISRO works with.
Suddenly it'll start making sense, how ridiculous the mass fraction and isp number crunching is.

Anyway, I look forward to 'raakit ki garajna' on the 5th of June.Its going to be a historic day for ISRO and Desh !
(Shoddy camera work expected as usual and a couple of articles on India's sanitation and poverty too,briturds aid discussion etc.im ready for all of it :mrgreen: )
I wish I could be at Pulicat lake for the launch,will have to miss this golden opportunity though.

Vivek K
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Re: Indian Space Programme Discussion - Sept 2016

Postby Vivek K » 04 Jun 2017 06:56

ISRO has made Indians proud by their successes. They now have the opportunity to look at other fuels and aerodynamic configurations.

But right now is not the time for Rona dhona. Let us wish ISRO a successful first flight of the GSLV MK3.

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Re: Indian Space Programme Discussion - Sept 2016

Postby sanjaykumar » 04 Jun 2017 07:47

(Shoddy camera work expected as usual and a couple of articles on India's sanitation and poverty too,briturds aid discussion etc.im ready for all of it :mrgreen: )

That's the spirit!

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Re: Indian Space Programme Discussion - Sept 2016

Postby Prithwiraj » 04 Jun 2017 08:28

Why historically we never relied on Russian launcher for GSAT launch and gravitated towards Ariane launchers?

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Re: Indian Space Programme Discussion - Sept 2016

Postby Varoon Shekhar » 04 Jun 2017 08:38

Probably because they didn't want to become overly dependent on the Russians. There were already major Russian interests in the Indian economy. Also, there has always been an affinity and soft corner for the French in India, the relationship has been largely trouble free. So when the French offer to launch satellites into GTO, at competitive rates, India was very agreeable. Actually, it shows Indian maturity and independence of spirit, not to go to the Russians on this matter.

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Re: Indian Space Programme Discussion - Sept 2016

Postby SSSalvi » 04 Jun 2017 10:30

ISRO has published details of Launch of GSLV MkIII D1 / GSAT-19 mission scheduled for Monday, June 05, 2017 at 17:28 ht IST.

Flight profile and path is condensed here from the Mission Brochure.

Image



Notice that the path is totally passing over the populated landmass indicating the confidence that ISRO has in its maiden launch of GSLV MkIII,

Also note that the Core motor of 1st stage is ignited AFTER the initial liftoff by strap-ons upto an altitude of 41 kms !

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Re: Indian Space Programme Discussion - Sept 2016

Postby A Nandy » 04 Jun 2017 11:25

The 25 and a half hours countdown for the first developmental flight of Isro's GSLV Mk III, carrying communication satellite GSAT-19, will begin at 3.58pm on Sunday. GSLV Mk III is scheduled to lift off from Satish Dhawan Space Centre in Sriharikota at 5.28pm on Monday.


http://timesofindia.indiatimes.com/indi ... 977396.cms

There seems to be a lot demand for launching swarms of nano satellites. Many companies are getting into space based mapping and navigation. Maybe GSLV can launch a massive number of such satellites in 1 shot(400+?)

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Re: Indian Space Programme Discussion - Sept 2016

Postby Singha » 04 Jun 2017 14:13

I am curious why the payload fairing separation is at 3:45 rather than just before 16:05 when the C25 stage will shut down. it might save a ton or two i suppose ?

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Re: Indian Space Programme Discussion - Sept 2016

Postby prasannasimha » 04 Jun 2017 14:20

^^^SSSalvi o don't think that it is over significant land mass . If the flight footprint is taken it is all over the ocean just like previous GTO launches. The 3D rendering is just giving that impression.


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