Indian Space Program: News & Discussion - Sept 2016

[Singha]

More than obese moon missions we need first a reliable workhorse of the ariane5 kind which can put 2x large sats into gto or 1 massive space stn module. Solve the transponder shortage for hdtv once and for all.

Secondly a new simpler cheaper pslv using gslv tech with high launch rates to further build up local satellite industry....esp military payloads in low and medium orbits

[hnair]

A little bit visible here

Wonder why that particular choice, instead of having two doors, one land side and the other sea-facing.

This "4T GTO onlee" is like frail Agni IV lobbing "1.5 tonnes to 3000 kms only" kind of modesty, for the sake of "advanced nations", who will feel suddenly inadequate and not so advanced. IIRC, MKIII can scale up to 2x the current published weight to GTO, with minimal incremental changes in overall design. The upper stage needs to be proofed to high reliability for both orbital insertion and re-lighting in vacuum.

[Varoon Shekhar]

Really nice to hear the official announcement on the ISRO website! On the nasa spaceflight forum, a couple of posters have called the GSLV Mark 3 'odd looking', though they also wish it success! What is odd about it? It is kind of stocky, but so what? Such vehicles have been known to fly before haven't they?

[Singha]

looks like we follow the ariane template of firing only the solid fuel boosters (we cast them in one block and cut them into half to make sure grain sizes match) at launch and the main liquid engine later. the french use a cryogenic liquid hydrogen and oxygen mix for Vulcain core stage and a different mix (not liquid hydro and oxygen) for the Aestus2 upper stage engine. similar height to gslv mk3 but 1 m fatter.

must be using very light materials and some uber t:w ratio engine design too given their tfta reputation and throw weight of a volvo bus.

the american delta4 has a single core liquid engine for all but its heaviest config where two more such liquid engines are added on the side.
and they fire all 3 together. keeps things common. its called common core engine. liquid hydrogen and oxygen for all stages. it replaces their space shuttle main engine as the tip of spear product for the khan. the american rockets tend to be really tall...the delta4 is nearly 30m taller than gslv mk3.

given that both the leading western heavies use liquid hydro + oxy mix , what is the boo boo about liquid oxy + kersonese mix (semi cryo engine) being better and yindu missing the boat on that and having to play catch up? safety and handling or simpler and reliable engines ?

[vina]

looks like we follow the ariane template of firing only the solid fuel boosters (we cast them in one block and cut them into half to make sure grain sizes match) at launch and the main liquid engine later. the french use a cryogenic liquid hydrogen and oxygen mix for Vulcain core stage and a different mix (not liquid hydro and oxygen) for the Aestus2 upper stage engine. similar height to gslv mk3 but 1 m fatter.

must be using very light materials and some uber t:w ratio engine design too given their tfta reputation and throw weight of a volvo bus.

the american delta4 has a single core liquid engine for all but its heaviest config where two more such liquid engines are added on the side.
and they fire all 3 together. keeps things common. its called common core engine. liquid hydrogen and oxygen for all stages. it replaces their space shuttle main engine as the tip of spear product for the khan. the american rockets tend to be really tall...the delta4 is nearly 30m taller than gslv mk3.

given that both the leading western heavies use liquid hydro + oxy mix , what is the boo boo about liquid oxy + kersonese mix (semi cryo engine) being better and yindu missing the boat on that and having to play catch up? safety and handling or simpler and reliable engines ?

1. This goes back to the posts I made long ago about how the GSLV Mk 1/2 are poorly designed (they put the solid rocket in the core and the liquids outside and hence carry some 30tons of spent casing deadweight for around a full minute) and so what is a 4T to GTO class vehicle puts only 2.5 tons.

2. The MKIII too suffers from having the Vikas engines (UDMH + N2O4) and the reliance on solid boosters leaves it with a poor(er) mass fraction compared to it's analogues.

3. The MkIII core stages are not lit on the ground. The Ariane V core stage is lit on the ground. The core in the Ariane V is a full cry stage and hence a far higher specific impulse compared to the Vikas based L110 cluster

4 . The Titan V is the benchmark. The Russian RD-180 stage is an absolute beast. Puts out around 4MN thrust , and can throttle down to nearly 40% thrust. The net result is the Titan V is a 2 stage to orbit vehicle, with probably the highest mass fraction of the vehicles out there.

5. The reason the Titan V is efficient is because the high(er) specific impulse compared to the Vikas engines and in addition it is a staged combustion cycle with ability to throttle. The Vikas is open cycle and cannot be throttled . It is lit and let go. That is probably the reason why the GSLV Mk2 and also the MKIII lug dead weight (the MK1/2 doesnt have a choice thanks to compromised design carried over from PSLV components), while the MkIII carries it for around 15 to 20 secs (it carries around the 75 ton of spent casing in the SRB after the L110 ignites before the SRBs are jettisoned).

So the MKIII is a classic case of a mountain going into labor and producing a mouse. This is a 8 T to GTO class vehicle which unfortunately carries only 3.2 tons in the first launch in June 5. This desperately needs to cluster 2* 2MN Kerosene Lox instead of the UDMH/N204 engines in the L110 core and you can have a Titan V class vehicle.

The L110 stage is a relic and really a wasted effort that is 20 years too late. They should have clustered the 4 Vikas engines into the core for the GSLV Mk1/2 like in Airane 4 or the LM 3/4 and put solid boosters. The L110 will be discarded within 5 years.

[Singha]

sooner they get the SCE200 1st stage into service the better I think.
https://en.wikipedia.org/wiki/SCE-200

why are we not firing the core stage at t=0 ?

i had missed it in ariane5 pix because the liquid flame gets overshadowed by the solid rockets

[Singha]

delta4 and angara have imo done the right thing by doing away totally with solid boosters and going with a common liquid engine which they cluster as needed like 2 or 4 or none

URM-1: first stage and boosters[edit]
The Universal Rocket Module (URM-1) forms the core of every Angara vehicle. In the Angara A5, four additional URM-1s act as boosters. Each URM-1 is powered by a single NPO Energomash RD-191 burning liquid oxygen and RP-1 (kerosene).[13]

[Gagan]

Vina
A GSLV MK2 with 2 or 4 vikas as the core will be a very interesting vehicle
All liquid
UMDH/N2O4 first and second stages,
Cryo 3rd stage

What if they make the core solid in MK2, burn for longer? No lugging around of deadweight. Does that improve the throw weight of the MK2?

[Neela]

Disha, Vina,prasanna, others

Just 1 question from my side. Keeping in mind consolidation, reduction of complexity, handling costs, competition,scalability and cost/kg, what are the forward looking preferred stages ISRO should opt for , for all types of payload to GTO ( Say from 1Tonne - 15Tonnes) .

[nirav]

Disha, Vina,prasanna, others

Just 1 question from my side. Keeping in mind consolidation, reduction of complexity, handling costs, competition,scalability and cost/kg, what are the forward looking preferred stages ISRO should opt for , for all types of payload to GTO ( Say from 1Tonne - 15Tonnes) .

I believe the best answer to that question is one given by ISRO in the configuration they eventually select.
Simply because we just do NOT have access to all the variable values.

There is too much brochure number quoting and criticism of ISRO on this thread,all based on assumptions and speculation.

[Ashokk]

The presentation by Dr.V.Narayanan from LPSC in AI2017 on "Cryogenic Propulsion Systems for ISRO Launch Vehicles" contained lots of info on the 2000kN semi cryo that ISRO is working on and some possible future GSLV configurations. Luckily someone has posted pictures of the of the slides here.

[Gagan]

Half the thrust as the RD-180 !
SCE 200: 2000kN
RD-180: ~4000kN - but this is a dual exhaust engine which shares pumps and tanks

So a RD-180 like dual exhaust engine is possible, which will make it at par.
This is an amazing development by ISRO !!!!!!!

[VenkataS]

I notice that there is only one road "Sriharikota Road" leading into SDSC and SHAR. For such a high profile installation shouldn't we have an additional road as backup?

[Singha]

its not exactly marketed as a tourist destination (though it could be on the shore side). I am sure marcos and CISF have a say in all such perimeter and security matters and lets leave it there. the bigger parts come by ship from trivandrum right? only satellites get shipped in shock monitoring trucks from isro bangalore (I have seen one such convoy).

Vina is right that the 1st stage with 2 x vikas engine is far behind comparable heavy size launchers and will need replacement as soon as possible to realize the potential of the chassis and upper stage engine. the vikas has half the chamber pressure of vulcain2 on ariane5 and uses dated udmh fuel vs the std lox/loh or lox/kerosene combos seen worldwide. ideally we need 3 liquid engines (1 core and 2 strap one) the same engine for ease of use and do away with the solid boosters which are wasted in the sea - we need to figure out a way to recover the 1st stages for reuse to drive down cost also. kerosene is likely safer & cheaper to use than volatile LOH as everyone from aviation fuel/brahmos use it. so semi cryo LOX/kerosene is right choice.

sooner the new 1st stage comes the better.

SpaceX seems trying to disrupt the field like google/amazon/fbook have turned a lot of fields on their heads. and they seem to have full access to nasa body of knowledge and resources, plus decades of data bank and the vast materials and engine expertise of the khan.

[disha]

Disha, Vina,prasanna, others

Just 1 question from my side. Keeping in mind consolidation, reduction of complexity, handling costs, competition,scalability and cost/kg, what are the forward looking preferred stages ISRO should opt for , for all types of payload to GTO ( Say from 1Tonne - 15Tonnes) .

You need all., there is no one-size fits all or there is no one propulsion technology to conquer all. Put it this way., China is spending big bucks to catch up on solid motor tech. It has got several on test bed but none operational. NASA is working on a big solid booster that will relegate GLSV-Mk III's booster to 3rd place. Note that: 80% of thrust on space shuttle came from the SSBs.

Are 3 out of 4 major agencies idiots to still stick with solid boosters? That is the question to ask.

Semi-Cryo has a marginal specific impulse advantage over the NO4/MDMH liquid engines., except that they are cleaner and non-carcinogenic. However the NO4/MDMH have a unique property of being hypergolic., that is they burn on coming in contact and have simpler circuits., and they are restartable and reliable in deep space (MOM!). Currently not many have deep space semi-cryo restartable engines. Cryo is already known.

Now if one takes ion-thrust engines., it beats the pants out of cryo! But you cannot use it to launch any meaningful payload from earth.

Hence it is not just looking at a table of specific impulses and putting in your favorite or taking out your most hated engines and launch. That is not how it works.

Further., it is funny that arm-chair "rocket scientists" fall into the trap of "bigger is better" measurements. What will you do with 100 tonnes to LEO if it costs 2000 Cr. Rs. to launch and can be launched only once a year and carries a heavy risk? Cannot 20 x 5 tonnes 100 Cr launches be done to distribute cost and spread risk?

[disha]

given that both the leading western heavies use liquid hydro + oxy mix , what is the boo boo about liquid oxy + kersonese mix (semi cryo engine) being better and yindu missing the boat on that and having to play catch up? safety and handling or simpler and reliable engines ?

How does one do rona-dhona then? Or measurement contests?

[symontk]

its not exactly marketed as a tourist destination (though it could be on the shore side). I am sure marcos and CISF have a say in all such perimeter and security matters and lets leave it there. the bigger parts come by ship from trivandrum right? only satellites get shipped in shock monitoring trucks from isro bangalore (I have seen one such convoy).

Only SDSC employees and tribals need to take that road. No one else is allowed. earlier the SDSC staff used to stay there. But those have been removed long back. Its no entry site

Rocket parts come thru truck only, no ship used

Vina is right that the 1st stage with 2 x vikas engine is far behind comparable heavy size launchers and will need replacement as soon as possible to realize the potential of the chassis and upper stage engine. the vikas has half the chamber pressure of vulcain2 on ariane5 and uses dated udmh fuel vs the std lox/loh or lox/kerosene combos seen worldwide. ideally we need 3 liquid engines (1 core and 2 strap one) the same engine for ease of use and do away with the solid boosters which are wasted in the sea - we need to figure out a way to recover the 1st stages for reuse to drive down cost also. kerosene is likely safer & cheaper to use than volatile LOH as everyone from aviation fuel/brahmos use it. so semi cryo LOX/kerosene is right choice.

sooner the new 1st stage comes the better.

SpaceX seems trying to disrupt the field like google/amazon/fbook have turned a lot of fields on their heads. and they seem to have full access to nasa body of knowledge and resources, plus decades of data bank and the vast materials and engine expertise of the khan.

Nothing is going to replace the power and grandeur of solid motors. For escaping the atmosphere, you need unadulterated energy which only solid can provide at a less expensive rate

[g.sarkar]

GSLV on the tracks looks like a gigantic ash covered lingam for the Puke motorhams to drool at. ISRO ki Jai.
Gautam

[JTull]

Presently, size of various engines are less important than scaling up current capabilities to launch atleast once every month or beyond.

That's where we are furthest behind other 4 players.

[Ashokk]

Half the thrust as the RD-180 !
SCE 200: 2000kN
RD-180: ~4000kN - but this is a dual exhaust engine which shares pumps and tanks

From the slides it seems that there is a SC400 in the works as well.
One of the slides says that we can put 16.3 Ton to GTO with two SC400 in the first stage, one SC400 in the 2nd stage & a C27 as third stage.

[Singha]

16t is there any single sat that large needed in gto?

The kh12 sats of that weight x 20m long orbit in 400km i believe...even gslv mk3 with a huge payload fairing should be able to achieve 8tons..to 400km orbit..

These payloads are likely to be very rare and with long life. We should keep a special version of gslv with 2 extra boosters for such rare cases

[disha]

Technology is fast evolving., on one end satellites are getting miniaturized and a swarm of nano satellites are doing a far better job than a single satellite. On the other hand need for large satellites are also coming through. How do you launch the next gen radar imaging satellite which have large antenna requirements? Or launch a space telescope?

That is why rocket designers are moving towards interchangeable stages and evolving towards ULVs. If one looks at Arianne, it has several variants. Similarly one looks at Delta IV and it can go from medium to heavy. If one looks at GSLV-Mk-X with SC-400 engines., it looks like a Delta!!! In some ways it looks like Arianne and in other ways it can evolve like Delta.

If you are a rocket designer., you want reliable engines and tested stages and combinations thereof. And from there you look at your payload requirements and put together a rocket accordingly. You now have a versatile launch service. Your payload could be a tonne of screws to be delivered to a future mining colony on moon or gently launch humans into space.

[Sridhar]

16t is there any single sat that large needed in gto?

The kh12 sats of that weight x 20m long orbit in 400km i believe...even gslv mk3 with a huge payload fairing should be able to achieve 8tons..to 400km orbit..

These payloads are likely to be very rare and with long life. We should keep a special version of gslv with 2 extra boosters for such rare cases

The main use case for the super heavy lift launchers will be for large interplanetary spacecraft, e.g. crewed missions to Mars. Even in that case, this is not the only way one can execute such a mission (the other possibilities include an assembly in space concept with different smaller components of a large spacecraft being launched separately and put together in orbit). In any case, this is merely being discussed as a theoretical possibility for now, with a several decades long development cycle.

[disha]

From the slides it seems that there is a SC400 in the works as well.
One of the slides says that we can put 16.3 Ton to GTO with two SC400 in the first stage, one SC400 in the 2nd stage & a C27 as third stage.

One has to be careful on extrapolating from a slide., may be a design feasibility was carried out based on existing and near-future capabilities and a presentation made accordingly. It does not mean it is a sanctioned project., it merely means that it is feasible. It will be one among several proposals on what to do with that much of a launch capability. It is almost 100 tonnes to LEO. That is huge!

[prasannasimha]

The cheapest option in the dense atmospheric phase still remains the solid rocket booster.That is why it was used even in the space shuttle. You may pooh pooh it etc but that is the truth whatever the lsp may read out as a number. Also sheer thrust is higher even with a lowIsp
See for example

https://space.stackexchange.com/questio ... irst-stage

[Singha]

my main use case would be IMINT sats of large size resolution 10cm-25cm range for which the current optical tech needs a huge KH12 size chassis including a 2.5m mirror. the KH12 is closely related to the hubble space telescope and infact hubble borrowed most of its tech and allegedly size and look from lockheeds kh11 and kh12 design. that is what the web claims.

being a billion$$ asset it must carry a lot of fuel for orbital corrections and serve a long life, apart from being lofted with a very reliable launcher.

the curve of driving down resolution from our current 50cm to 10cm seems nonlinear in vehicle size and weight.

but perhaps with huge improvements in CPU, GPU, digital imaging sensors and image/video processing techniques , the old behemoths are no longer needed and agile swarms of much cheaper 1-2t satellites are all thats needed now... DSLRS still rule at low light & high zoom w/tripod, but smartphones have caught up big in most areas....for most people needs smartphone looks enough.

[disha]

Will moving this thread from "military" forum to "technology and economic" forum make more sense? Just letting out a trial balloon.

[Gagan]

Just so that people know, the Vikas' on the Mk-3 are uprated engines - similar design, but much bigger.
All vikas' are not the same.

Similarly, the fuel of the Vikas has changed from UDMH/N2O4 to UH-25/N204 in recent engines, UH-25 being a derivative of UDMH

[Singha]

I want a vast sheet of liquid blue sunflame from LOX/kerosene first stage ..... like the SS18 it should not merely be a GSLV but a STATEMENT.

[hnair]

People nowadays want an H&DLV, that can lift a Lal Qila into GTO SLV, then ASLV, PSLV and finally GSLV itself was filled with frugal choices (compromises or "foolishness", if we go full-snooty) taking into account, what was considered as national objectives and that is how it will remain. We really dont have a scientific community, that is already bristling with optical, infra, ultra or radio telescopes, who can define mission objectives which demand huge payloads to be hauled into space. Nor do we have a jernail-community that gets triggered when peering into Kremlin bedrooms or Trump tower hot tubs

(Defining basic objectives before deciding on tech is something India's engineering online community is not serious about. A similar debate on CATOBAR carriers, now hijacked by khan-pasanders, talk about "number of EMALS", when we dont even know which wars or naval action India wants to get into nor what are these far-shores that we have to defend or covet)

I want a vast sheet of liquid blue sunflame from LOX/kerosene first stage ..... like the SS18 it should not merely be a GSLV but a STATEMENT.

er, Satan uses same hypergolics as Vikas engines.

For me, it is fascinating to watch is the test of a C25 at Mahedragiri or SSME (RS36) test firings. Flame drops like The Partysquad video

[Singha]

I call my proposed first stage as 'Bheesma'
people should tremble...
concrete huts miles away should start shedding fragments...
the roar of the first climb should scatter all animals like sparrows in a wide swathe...
a unheard of cone of clear blue flames from 3 mighty engines...
the heavens must part to allow passage to the undefeatable flame of dharma...and devas pay homage to its majestic passing

let the drums be beaten and the Conch shells be blown...
so it is written in the ancient prophesies and so shall it be done.

[sudhan]

^Add to it a night time launch, with airborne coverage showing the rocket breaking through clouds, lighting up the skies like a miniature Sun..

The launch should shake and light up the area miles around the launch pad..

[Ashokk]

GSLV-Mark III set for June 5 launch: Isro

The Liquid Propulsion Systems Centre (LPSC) director S Somnath also told TOI that "GSLV-MK III is a possible human-rated launch vehicle by virtue of its design features including its simple module, its technology for lesser propulsion system, lesser accelerator levels, lesser dynamic pressure load and lesser noise or benign acoustic levels" Further, it has more redundancy which means that if an electronic part fails other part will take over the task to propel the vehicle forward, he said.

It may be noted that the term `human-rated' certifies a spacecraft, launch vehicle or airplane as worthy of transporting humans.

GSLV project director G Ayyappan also indicated that it is for the first time that a launch vehicle is designed with Ogive shaped curvature to able to control the air pressure and to check noise with its acoustic suppression system.

Conceived in 2002 at a total project cost of Rs 2900 crore, the GSLV-MK III will be fitted with a fully indigenous cryogenic engine of 20 ton thrust with 28 ton propellant loading, LPSC scientists said.

This cryogenic engine has 2.5 times more thrust than the previous cryogenic engine with 12 ton thrust. Similarly, this launch will have 2.46 times more thrust with two solid motors and 2.1 times more thrust of liquid boosters with 116 tons of liquid propellants loaded as against the earlier 40 tons, VSSC scientists said.

[Singha]

delta4 heavy. in typical khan style, its more of a engine with a small payload & pax strapped to it. 3 immense liquid engines bolted together . so heavy it almost seems to hang in the air and speed up like a turtle.

https://www.youtube.com/watch?v=wCy401hkXuk

[rsingh]

I call my proposed first stage as 'Bheesma'
people should tremble...
concrete huts miles away should start shedding fragments...
the roar of the first climb should scatter all animals like sparrows in a wide swathe...
a unheard of cone of clear blue flames from 3 mighty engines...
the heavens must part to allow passage to the undefeatable flame of dharma...and devas pay homage to its majestic passing

let the drums be beaten and the Conch shells be blown...
so it is written in the ancient prophesies and so shall it be done.

+ And what about green back turtels?

[ldev]

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%

[Gagan]

Idev ji
Those guys are using cryos or semi cryos from the first stage itself, where as (with due reverence to Vina ji), MK-3 has the twin UH-25/N2O4 Vikas.

If we did a cost analysis, the list would perhaps be exactly upside down

I wonder, what would the Mk-3 be like, if they had clustered 4 Vikas' instead of 2 in the first stage?

[ldev]

^^
I wonder how much of the difference is attributable to the lower isp of the fuel and how much is because of the late stage separation (courtesy Vina )

PS: By the way I think ISRO did the right thing by initially going for UH-25/N2O4 , easier to handle/store and more stable. Better to get the rocket launches going rather than wait for perfection aka LCA.

[nirav]

It's important to ascertain cost/kg to GTO for all the launchers listed above.

Also what's the timeline for ISROs heavy satellites.
For the moment and the near future the MK3 with its current configuration will serve us well and possibly be an end to arianespace launching our sats.

While discussing foreign launchers it's important to remember our space program is for our needs keeping in mind various constraints that we face.

ISROs approach in being incremental is quite risk averse and bold where it's needed.

Once the MK3 is reliably operational (it's still a very new rocket) it will evolve further. ISRO has a well planned growth path for its later rockets.

Making money for GoI by launching foreign heavy sats is a byproduct of what ISRO does.
It's not the prime goal.

[Gagan]

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.