Indian Space Program: News & Discussion - Sept 2016

JayS · Post by **JayS** » 15 Nov 2018 16:35

Singha wrote:Gslv mk3 has matched the ariane4 figure to gto and by attaching 4 boosters to first stage will it improve?

Sats are getting bigger for tv and internet but 7t to leo and 4t to gto should cover a lot of the addressable market

Some of the heavy sats are mil payloads and not launched outside of home country

Is there a mk4 being planned to match the arian5 gto?

Isn't ISRO working on ULV/HLV project..? That should replace everything we have today and have a modular LV family for across the spectrum launch weight capability upto 16T I think.

hnair · Post by **hnair** » 15 Nov 2018 17:01

Singha wrote:Gslv mk3 has matched the ariane4 figure to gto and by attaching 4 boosters to first stage will it improve?

Sats are getting bigger for tv and internet but 7t to leo and 4t to gto should cover a lot of the addressable market

Some of the heavy sats are mil payloads and not launched outside of home country

Is there a mk4 being planned to match the arian5 gto?

An oversimplification type answer - with an existing set of engines/motors (developed after lots of years and expenses), it is not by increasing the size of lower stages or adding boosters alone that increase the payload. It is usually done by increasing the upperstage's fuel load. If the fuel load goes up, the upper stage gets more burn time to accelerate a larger payload to orbital velocity. Once that part is settled, you add extra boosters to push up that heavier upperstage through the dense lower atmosphere at a structurally safe speed.

MKIII's CE stage's fuel loading is probably not full tank as of now and the upcoming semi-cryo stage will add more kick during the post-SRB phase, once it punches through the clouds. Stretching the cryo tanks is another option.

This is a young but really energetic puppy. Remember how PSLV evolved its payload to SSO from 900kgs to its current max payload of 1800kg? Good times ahead

SriKumar · Post by **SriKumar** » 15 Nov 2018 18:14

Rishi_Tri wrote:https://www.isro.gov.in/sites/default/f ... 0D2%20.pdf

Details on Launch Vehicle, Satellite, flight path including times, and Very Good Graphics.

The final position of the satellite in GSO will be over Iran roughly; at 55 East.

Vips · Post by **Vips** » 15 Nov 2018 18:51

JTull wrote:There's no mk4. Jut that the core-liquid stage will be replaced by Semi-cryo. But with 4.5 tonnes to GTO already achievable, I wonder what we will use it for.

The present plan is to try out the semi-cryo stage at the core of MkIII in place of its liquid fuel engine, without changing the design. This would raise its muscle power 50% — from four to six tonnes. Gradually it would be enhanced to 10 tonnes and eventually 50 to 60 tonnes, by developing a modular super vehicle with many additions or strap-ons built around the main structure. FH used a similar tactic, according to Dr. Sivan, who oversaw preliminary semi-cryo related works while he was ISRO’s propulsion head until recently.

Gagan · Post by **Gagan** » 15 Nov 2018 19:18

Something like this is possible with the new GeoEye camera

A satellite in geostationary orbit with a very high resolution - billion pixel or gigapixel camera, which can constantly keep taking pictures 24x7, videos 24x7
The resolution is only going to go up.
Now no need to wait for a satellite to pass overhead. The enemy can be watched 24x7.

Or NaMo can see who dropped a banana peel on Assi-Ghat, or how much work has been done on a flyover in Varanasi, 24x7, from the comfort of the PMO

Below is a low res example. The Chinese Gaofen4, focuses on two large swaths in the SCS and off the coast of Shanghai into the pacific
https://www.youtube.com/watch?v=DxbPCV_kbpw

Ashokk · Post by **Ashokk** » 15 Nov 2018 19:48

GSLV Mk III-D2 / GSAT-29 Mission Lift-off and Onboard Camera View

Supratik · Post by **Supratik** » 15 Nov 2018 20:22

More info on the satellite.

https://swarajyamag.com/science/why-isr ... ou-thought

SaiK · Post by **SaiK** » 15 Nov 2018 22:22

Mr Sivan, ISRO wrote:Baahubali or the GSLV Mk-III - 641 tons, 43 meters, heaviest, shortest.

"If this launch succeeds then India's Baahubali or the GSLV Mk-III will be declared operational," Mr Sivan added.

Chandrayan 2 core will be declared operational
---

^^ on the q/v band.. it is a great move for digital India and high speed internet. for ex: at home network AD7200 wifi router uses 60ghz for 10gbps bandwidth for a max of 30 ft.

. I have to find devices to match these/realize... [ha ha ha]

SSridhar · Post by **SSridhar** » 16 Nov 2018 09:17

SriKumar wrote:The final position of the satellite in GSO will be over Iran roughly; at 55 East.

GSAT-16 is also located there.

pankajs · Post by **pankajs** » 16 Nov 2018 12:41

prasannasimha · Post by **prasannasimha** » 16 Nov 2018 13:03

Nov 16, 2018 : GSLV Mk III-D2/GSAT-29 Mission: The second orbit raising operation of GSAT-29 satellite has been successfully carried out today (November 16, 2018) by firing the Liquid Apogee Motor (LAM) engine of the satellite at 1027 Hrs IST for a duration of 4988 sec

prasannasimha · Post by **prasannasimha** » 16 Nov 2018 22:22

Please desist placing other space program related matter. If required link it to international aerospace discussion and give link here

prasannasimha · Post by **prasannasimha** » 17 Nov 2018 20:59

From ISRO twitter feed

Final orbit raising operation of #GSAT29 has been successfully carried out today by firing the Liquid Apogee Motor engine for 207 secs. The satellite is in its final Geo Stationary orbit now. Both solar arrays & reflectors have deployed.

Haridas · Post by **Haridas** » 18 Nov 2018 00:50

JTull wrote:There's no mk4. Jut that the core-liquid stage will be replaced by Semi-cryo. But with 4.5 tonnes to GTO already achievable, I wonder what we will use it for.

resulting lowrr $/kg is more important.
As for what to do with it. Launch two sats in one shot.

Haridas · Post by **Haridas** » 18 Nov 2018 01:14

hnair wrote:
Singha wrote:Gslv mk3 has matched the ariane4 figure to gto and by attaching 4 boosters to first stage will it improve?

Sats are getting bigger for tv and internet but 7t to leo and 4t to gto should cover a lot of the addressable market

Some of the heavy sats are mil payloads and not launched outside of home country

Is there a mk4 being planned to match the arian5 gto?
An oversimplification type answer - with an existing set of engines/motors (developed after lots of years and expenses), it is not by increasing the size of lower stages or adding boosters alone that increase the payload. It is usually done by increasing the upperstage's fuel load. If the fuel load goes up, the upper stage gets more burn time to accelerate a larger payload to orbital velocity. Once that part is settled, you add extra boosters to push up that heavier upperstage through the dense lower atmosphere at a structurally safe speed.

MKIII's CE stage's fuel loading is probably not full tank as of now and the upcoming semi-cryo stage will add more kick during the post-SRB phase, once it punches through the clouds. Stretching the cryo tanks is another option.

This is a young but really energetic puppy. Remember how PSLV evolved its payload to SSO from 900kgs to its current max payload of 1800kg? Good times ahead

Hnair, I owe you the book you lent me.
For a given set of available stage mass-fractions for various stages (where the stage thrust ratio to mass of all that is above the engine is with in certain acceptable range) there is an optimum ratio of stage mass compared to the mass of the stage above it. So up rating one stage on mass fraction or stage mass does not result in best system performance rating.

For best results more engineering effort is spent to fine tune Mass fraction of upper stages, that results in using smaller mass engine (with corresponding smaller thrust). So at maximum payload efficiency confign, the penultimate stage kicks the upper stage at higher elevation (compared to best elevation angle for current velocity), allowing the upper stage to gradually plunge back to earth (in no case reaching below 110 km altitude), the increased available time above atmosphere is used by the small engine thrust to burn enough fuel to impart velocity to the residual craft to reach the point where ISP loss due to gravity becomes zero (cicular orbital speed corresponding to the local altitude) [for this mission this altitude was higher then mission target, and is a measure of the headroom available for future heavier payload]. Beyond this point the engine is configured for best possible ISP only (recall GSLV mk2 CUSP with two thrust modes ! ) and additional thrust beyond this point onwards generally result in elliptic trajectory. For non restartable engine all fuel can't be spent because apogee would be more than targeted circular orbit radius (it will be contraproductive beyond that).

Indranil · Post by **Indranil** » 19 Nov 2018 11:25

Hnair sahab, to bolster Haridasji's points, I must point out that Mk3 flew with the full fuel load of the CUS. So, we can't expect much more from the CUS.

For payloads of 4.5 tons using L110, you will see more refined usage of the S200 and L110 stages. The biggest scope right now is to reduce the interstage burn time between the L110 ignition and S200 separation. A near 30 second overlap is not ideal from the rocket equations. Right now, they are doing this to ensure that the fuel is "settled" in the L110 stage and that both the engines light up etc. As their confidence in the stage grows, you will see this interleave period reduce to between 5 and 10 seconds.

Also, I agree with HAridasji, the today's race today is $/kg. And SC160 (or SC200 whatever it turns out to be is the right step in that direction). Quite frankly, the development of the TSTO with SC500 stage is more interesting to me than the HSP program.

JayS · Post by **JayS** » 19 Nov 2018 15:11

Haridas wrote: For a given set of available stage mass-fractions for various stages (where the stage thrust ratio to mass of all that is above the engine is with in certain acceptable range) there is an optimum ratio of stage mass compared to the mass of the stage above it. So up rating one stage on mass fraction or stage mass does not result in best system performance rating.

For best results more engineering effort is spent to fine tune Mass fraction of upper stages, that results in using smaller mass engine (with corresponding smaller thrust). So at maximum payload efficiency confign, the penultimate stage kicks the upper stage at higher elevation (compared to best elevation angle for current velocity), allowing the upper stage to gradually plunge back to earth (in no case reaching below 110 km altitude), the increased available time above atmosphere is used by the small engine thrust to burn enough fuel to impart velocity to the residual craft to reach the point where ISP loss due to gravity becomes zero (cicular orbital speed corresponding to the local altitude) [for this mission this altitude was higher then mission target, and is a measure of the headroom available for future heavier payload]. Beyond this point the engine is configured for best possible ISP only (recall GSLV mk2 CUSP with two thrust modes ! ) and additional thrust beyond this point onwards generally result in elliptic trajectory. For non restartable engine all fuel can't be spent because apogee would be more than targeted circular orbit radius (it will be contraproductive beyond that).

Thanks saar for the info. That explains the plunge in altitude to 110km, didn't know this one.

Indranil wrote: Also, I agree with HAridasji, the today's race today is $/kg. And SC160 (or SC200 whatever it turns out to be is the right step in that direction). Quite frankly, the development of the TSTO with SC500 stage is more interesting to me than the HSP program.

I remember from Musk's PPT on BFR, ISRO was second to only SpaceX in terms of unit cost of launch. Perhaps ESA will catchup with their Prometheus engine, but it will be a decade before that can happen. ISRO has a good chance to undercut even SpaceX with its reusable LVs. We need to aggressively invest money in this. We can perhaps stop at 10-12T to GTO with conventional rockets. Any future capability can come with reusable LVs only.

prasannasimha · Post by **prasannasimha** » 19 Nov 2018 15:55

In all launches tge l9bbed height by the atmospheric burn is targetted higher. Gravity acts to speed up with loss of height and the next stage can kick off. This coasting time is commonly used by ISRO . PE being replaced by KE to our advantage.

suryag · Post by **suryag** » 19 Nov 2018 18:33

How can spacex be so cost effective ... even better than ISRO

Haridas · Post by **Haridas** » 19 Nov 2018 21:49

prasannasimha wrote:In all launches tge l9bbed height by the atmospheric burn is targetted higher. Gravity acts to speed up with loss of height and the next stage can kick off. This coasting time is commonly used by ISRO . PE being replaced by KE to our advantage.

Coasting is used only if payload need to be inserted in circular orbit, AND coasting always results in lower than maximum payload.

nam · Post by **nam** » 19 Nov 2018 22:47

Musk will obviously show SpaceX is cheaper than Isro. He is also using the larger weight carried on SpaceX vehicle compared to what Isro carries to show SpaceX in good light.

Even with the current vehicle, if the number of launches increases, Isro PSLV will become even cheaper. I so waiting for PSLV launches to be handed over to private sector. They can drive down the cost, real hard.

When ISRO starts getting in reusable vehicles, we will be cheaper than what SpaceX can throw. However the pace is glacial. Unfortunately ISRO being a GoI entity is not really interested in a race. Hopefully with the entry of private sector, this will be given the required push.

I cannot wait for TSTO/RLV/SSTO to kick in. Personally for me Scramjet engine development is more important than human space mission.

jaysimha · Post by **jaysimha** » 20 Nov 2018 11:57

Kumbh Mela in Thiruvanantha Puram.
National Systems Conference 2018 - DEI
http://www.nsc2018.in/
Dec 13 to 15
http://www.nsc2018.in/brochure/Brochure.pdf

disha · Post by **disha** » 21 Nov 2018 04:26

Ashokk wrote:GSLV Mk III-D2 / GSAT-29 Mission Lift-off and Onboard Camera View

The L110 stage separation is not in the video., but overall excellent video. Liked the IR camera.

Now we need DookhDarshan and ISRO to collaborate and shoot using very high speed cameras in IMAX. With all surround sound effect and show it in theatres across the globe. ISRO SHAR should have a museum in the SullurPeta town itself with IMAX theatre.

All Journos who visit SHAR need to go through the museum and make sure that they have passed the history of ISRO course.

I think there is a business to be made here to sell a PSLV pack or GSLV pack, with sullurpeta as a base to host all the geek-tourists coming to see the launches. Each pack can include a free pass to IMAX movie and inside pass to the launch.

disha · Post by **disha** » 21 Nov 2018 04:47

On the semi-cryo, it is still in paper stage. I do not think it has been approved yet.

Personally, I think the only reason ISRO should look at Semi-Cryo is to

a. Master the Sabatier process to create and pump rocket fuel for semi-cryo "reuseable stage" (https://en.wikipedia.org/wiki/Sabatier_reaction)
b. Minimize use of HNO4/UDMH propellant.

Otherwise it is unnecessary even for GSLV-MkIII.

Goal should be for ISRO to fast track the RLV project. This coupled with TSTO and GSLV MkII (upgraded)/MkIII will result in a class of reuseable and interchangeable stages lowering overall $/Kg.

Long term, ISRO should aim for permanent moon base with asteroid mining on moon base. If properly focused, all of this is achievable by 2040.

prasannasimha · Post by **prasannasimha** » 21 Nov 2018 09:52

SC200 is not a paper project. Cold flow test has been done. The test bed is under construction for the hot test. The original pkan was to send it for hot testing to either Ukraine or Russia but the plan seems ro have changed and ww seem to be doing testing here.
When reports say that it is not approved what they mean is not approved for integration into a space craft as still work is under progress that has been distorted to project not being approved !

JayS · Post by **JayS** » 21 Nov 2018 11:46

suryag wrote:How can spacex be so cost effective ... even better than ISRO

By comparing Apples vs Oranges. Reusable BFR with ideal planned utilization and cost effectiveness compared with existing expendable rockets. ISRO rockets are not even semi-cryo. And ISRO still comes second.

Hence I said, ISRO can comfortably undercut SpaceX with our own reusable LV. But ISRO doesn't have same priorities nor the same freedom to choose whatever catches their own fancy. Its driven by GOI's goals unlike a private company.

disha · Post by **disha** » 21 Nov 2018 12:12

prasannasimha wrote:SC200 is not a paper project. Cold flow test has been done. The test bed is under construction for the hot test. The original pkan was to send it for hot testing to either Ukraine or Russia but the plan seems ro have changed and ww seem to be doing testing here.
When reports say that it is not approved what they mean is not approved for integration into a space craft as still work is under progress that has been distorted to project not being approved !

Saar, it is still a paper *stage*. The engine is still on test bed and is being qualified. So far only cold flow tests have been done on the engine. Once the hot testing is completed it needs to be integrated into *stage* and the *stage* needs to be hot tested on ground before being integrated into a launch vehicle.

It took 3 years for the CE-20 engine to be hot tested and then cleared for flight test in an integrated test. Assuming hot test happens tomorrow, the SC *stage* (which is still on paper today) will not fly until 2021.

However ISRO is committed to put an Indian in space by 2021/2022. Hence any changes to core of GSLV MkIII will happen only after 2021. To me that is sometime in 2023-2025.

prasannasimha · Post by **prasannasimha** » 21 Nov 2018 12:57

The SC200 is a separate project with separate directors etc. Its not that we will do HDP nrglecting others. The hot test facility is nearly completed and testing should occur independently. HSP has been budgeted separately.

As far as not approved of course the engine is the major portion of the stage .Without it tgere is no stage! That doesnt mean to say ut is "not approved" Thats quibbling 9f words. Once the engine is proved the rest will happen.

Kakarat · Post by **Kakarat** » 21 Nov 2018 15:36

India’s big space leap; ISRO now readying flight to Venus

JTull · Post by **JTull** » 21 Nov 2018 15:56

disha wrote:
prasannasimha wrote:SC200 is not a paper project. Cold flow test has been done. The test bed is under construction for the hot test. The original pkan was to send it for hot testing to either Ukraine or Russia but the plan seems ro have changed and ww seem to be doing testing here.
When reports say that it is not approved what they mean is not approved for integration into a space craft as still work is under progress that has been distorted to project not being approved !
Saar, it is still a paper *stage*. The engine is still on test bed and is being qualified. So far only cold flow tests have been done on the engine. Once the hot testing is completed it needs to be integrated into *stage* and the *stage* needs to be hot tested on ground before being integrated into a launch vehicle.

It took 3 years for the CE-20 engine to be hot tested and then cleared for flight test in an integrated test. Assuming hot test happens tomorrow, the SC *stage* (which is still on paper today) will not fly until 2021.

However ISRO is committed to put an Indian in space by 2021/2022. Hence any changes to core of GSLV MkIII will happen only after 2021. To me that is sometime in 2023-2025.

To a bystander, either you were too cute in the nuances of your original post, or you are now just scrambling after being caught out spreading disinformation. Why didn't you put it in quotes/asterisk to begin with?

disha · Post by **disha** » 21 Nov 2018 17:09

Here you go without asteriska:

SC200 is still in design stage. It’s engine is in design stage. Its stage is not even in plan stage.

Some semi cryo- engine has been cold flow tested. Idea of hot testing it in Ukraine is a cruel joke. Why should it be hot tested in Russia? That suggestion itself is cruel.

Semi-Cryo will not come around until 2025. Even if it comes around till then.

disha · Post by **disha** » 21 Nov 2018 17:18

JTull wrote:...a bystander, either you were too cute in the nuances of your original post, or you are now just scrambling after being caught out spreading disinformation. Why didn't you put it in quotes/asterix to begin with?

Please do not standby. Please prove me wrong from available materials that SC200 engine is beyond design phase,

Also please prove that design is frozen at cold flow stage!

The entire boondongle of larger capacity is just that. I have been stating about efficient capacity since this thread (forum) started

JTull · Post by **JTull** » 21 Nov 2018 17:47

Ha ha. Talking about cute logic, your argument is akin to Red Bull F1 claiming that 2019 Honda engine is a paper design, and it hasn't even been approved yet! Or that, Kaveri is a paper design and it hasn't been approved yet, because it has not been fitted into LCA yet.

But since you doubt if the *stage* has been approved yet, here's the link

But you couldn't be bothered with a simple search when making conjectures (or deliberate mis-information).

JayS · Post by **JayS** » 21 Nov 2018 20:07

Guys cut the crap and keep it to the point. Where is the need to get personal..? Just say what you want to say. No one here knows everything. And everything said here is FWIW.

disha · Post by **disha** » 21 Nov 2018 21:00

FWIW, nod to go do a design of a stage does not mean a nd to a designed stage. My last on this.

Neela · Post by **Neela** » 22 Nov 2018 01:28

JayS wrote: Thanks saar for the info. That explains the plunge in altitude to 110km, didn't know this one.

Thank you for this. I noticed that dip too in the graph .

symontk · Post by **symontk** » 22 Nov 2018 09:11

Classic confusion for people what ISRO means to be an engine and stage

Engine - its a physics project, but only once this is done, staging design will start
stage - Stage design will be taken up, so that it can be incorporated into a "vehicle" and integrated with other components

Only when staging is successful, its approved for flight means, it will appear in a vehicle for launch

A new engine is always a laborious and costly process

hnair · Post by **hnair** » 22 Nov 2018 09:26

Haridas wrote:
hnair wrote:
An oversimplification type answer
Hnair, I owe you the book you lent me.

That is all yours'. Btw, I no longer do courier-drops outside that Safeway....

Am based at Trivandrum now

About my post - as I said in my first statement (quoted here), it was an oversimplification of why adding on boosters is not the solution, but adding more punch to the upper-stage is a good first place to start.

Haridas · Post by **Haridas** » 23 Nov 2018 04:59

hnair wrote: That is all yours'. Btw, I no longer do courier-drops outside that Safeway.... Am based at Trivandrum now.

I recall your plan, are you close to changing the Kerala political system? Vijayi bhava.

Haridas · Post by **Haridas** » 23 Nov 2018 05:07

Neela wrote:
JayS wrote: Thanks saar for the info. That explains the plunge in altitude to 110km, didn't know this one.
Thank you for this. I noticed that dip too in the graph .

Big rockets exprimentation is expensive, so discrete interval ballistic simulation is the most affordable tool to explore near practical rocket ballistics and orbital mechanics.

Unless of course if one is a maulana in Ulaanbaatar drinking goat milk kahwaa on green savanna pastures, under clear blue sky