Indian Space Program: News & Discussion - Sept 2016

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Re: Indian Space Program: News & Discussion - Sept 2016

Post by Mollick.R »

1m to lift off
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Re: Indian Space Program: News & Discussion - Sept 2016

Post by Mollick.R »

Lift off Narmallll
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Re: Indian Space Program: News & Discussion - Sept 2016

Post by Aditya_V »

One of the fortunes of being in Chennai, you get to see these launches with the naked eye
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Re: Indian Space Program: News & Discussion - Sept 2016

Post by Mollick.R »

Cyro stage parfanmence narmaal
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Re: Indian Space Program: News & Discussion - Sept 2016

Post by Mollick.R »

Hindi announcer "Raakit satelite ki selfie le raha hai" :rotfl: :rotfl: :rotfl:

On video/photo feed of on board camera.
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Re: Indian Space Program: News & Discussion - Sept 2016

Post by Ashokk »

DD plumbing new depths with the hindi commentary today :mrgreen:
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Re: Indian Space Program: News & Discussion - Sept 2016

Post by Mollick.R »

Satellite separated.
Mission successful

Bravoo
Jai Hind
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Re: Indian Space Program: News & Discussion - Sept 2016

Post by AdityaM »

Haridas wrote:
disha wrote:.....China does not have the capability to do a ASAT for GEO. And let us say if it does a ASAT at GEO, then they have screwed up spaces for all of humanity for 1000s of years. Even their GEO Sats will be in danger. And then they will end up taking out all geosats and we will go back to dark ages. Maybe S. Barbaria will be happy.....
IMHO it won't be that bad. ASAT debris will pollute the orbit just above GSO (my guess >98% mass)
Debris remaining on GSO will after few years eventually drift into graveyard longitude. Freeing up usable slots. The problem debris will be those in elliptic orbit that trespasses circular GSO orbit. This largely is debris of interceptor warhead, which will be very small compared to satellite weight.
Debris will be there only if there is an explosion. If there is just a slow kinetic impact enough to dent, disorient and damage the satellite or nudge it off course then it will cause negligible debris.

Again why announce a satellites capabilities. It may be good image building PR, but lays bare the strategic importance of these.
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Re: Indian Space Program: News & Discussion - Sept 2016

Post by JTull »

What are the advantages of a launch into higher apogee supersynchronous orbit instead of GTO? Is this due to a tradeoff between using satellite LAM motors versus using spare launch vehicle thrust to put in higher orbit?
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Re: Indian Space Program: News & Discussion - Sept 2016

Post by Singha »

Space agency ISRO's Christmas present for the IAF also happens to be its 17th mission.For Team ISRO, he had a "big New Year gift -- they will launch 32 missions in 2019," Dr Sivan said.
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Re: Indian Space Program: News & Discussion - Sept 2016

Post by Gagan »

As soon as the first stage was about to be shut off and just before the 2nd stage was ignited, Doordasha, stopped the live video of the rocket, and started showing ISRO chairman's face.
Bleddy DD walas are under ishtrict instructions not to show stage seperation or 2nd stage ignition (with the first stage still being lugged around and burning up due to the fire from the 2nd stage) on GSLV Mk2. That can be the only feasible explanation.
This time around, the DD camera did not do the schizophrenic up and down dance or the focus/unfocus nautanki just at the point of launch. Neither did they keep focusing on the dust cloud at the launch site, showing us nothing, until the rocket had climbed several kilometers in the air.

Sigh! DD will never graduate to show us stuff like, rocket has cleared the launch tower, stage separation.
Even the satellite separation video, was their camera focusing on the satellite feed on the main screen in control center.

Why, oh Why can't ANTRIX broadcast itself hain ji?
Why, oh why, can't they have onscreen telemetery hain ji?
Why can't they have a special hifi software to show us the launch data, have a high quality animation of the rocket hain ji?
Is it totally beyond ISRO and ANTRIX? Do these guys' telecast standards have to be stuck in the 1980s?

Finally why this undue secrecy, where it is not needed hain ji? India has the WORST TELECAST of all the top 5-7 space launching powers. This fact doesn't register with the powers that be at all? This doesn't cause any concern at all? GoI still stands behind the excuse that they invite tenders for broadcasters to come and cover the launch and only DD Chennai shows up - why can't ANTRIX and ISRO spend on high quality transmission, their own telescopes and various feed given to the television broadcast hain ji?

Being an individual who religiously watches their launches, and then ISRO related launches from Guyana, there is a big difference in the quality of the telecast

FWIW, both commentators are ex ISRO - who retired at fairly senior positions
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Re: Indian Space Program: News & Discussion - Sept 2016

Post by SaiK »

https://youtu.be/3k9yJI1i5UM

What was the error corrections for the drag he was commenting about at 30:*?
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Re: Indian Space Program: News & Discussion - Sept 2016

Post by Rishi_Tri »

Gagan wrote:As soon as the first stage was about to be shut off and just before the 2nd stage was ignited, Doordasha, stopped the live video of the rocket, and started showing ISRO chairman's face.
Bleddy DD walas are under ishtrict instructions not to show stage seperation or 2nd stage ignition (with the first stage still being lugged around and burning up due to the fire from the 2nd stage) on GSLV Mk2. That can be the only feasible explanation.
This time around, the DD camera did not do the schizophrenic up and down dance or the focus/unfocus nautanki just at the point of launch. Neither did they keep focusing on the dust cloud at the launch site, showing us nothing, until the rocket had climbed several kilometers in the air.

Sigh! DD will never graduate to show us stuff like, rocket has cleared the launch tower, stage separation.
Even the satellite separation video, was their camera focusing on the satellite feed on the main screen in control center.

Why, oh Why can't ANTRIX broadcast itself hain ji?
Why, oh why, can't they have onscreen telemetery hain ji?
Why can't they have a special hifi software to show us the launch data, have a high quality animation of the rocket hain ji?
Is it totally beyond ISRO and ANTRIX? Do these guys' telecast standards have to be stuck in the 1980s?

Finally why this undue secrecy, where it is not needed hain ji? India has the WORST TELECAST of all the top 5-7 space launching powers. This fact doesn't register with the powers that be at all? This doesn't cause any concern at all? GoI still stands behind the excuse that they invite tenders for broadcasters to come and cover the launch and only DD Chennai shows up - why can't ANTRIX and ISRO spend on high quality transmission, their own telescopes and various feed given to the television broadcast hain ji?

Being an individual who religiously watches their launches, and then ISRO related launches from Guyana, there is a big difference in the quality of the telecast

FWIW, both commentators are ex ISRO - who retired at fairly senior positions
:rotfl: DD will always remain DD. I am sure the only instruction would have been to show Mission Specialists' faces. Anyone with decent camcorder would have captured the stage separation from shores close to SHAR

But, all the same was perfect day to capture stage separation and falling off, and was waiting for it before the Mission Director's face came to occupy the screen for perpetuity. :rotfl:

Saw IAF folks also seated in audience.
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Re: Indian Space Program: News & Discussion - Sept 2016

Post by Singha »

The performance naarmal person has changed
This one is not so deadpan
I request the old one be brought back
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Re: Indian Space Program: News & Discussion - Sept 2016

Post by sudhan »

Saw my first launch..from Chennai. Was having DD live telecast on one hand and my cam on the other.

Nothing prepared me for what was to come..

Given the distance from Sriharikota, I was thinking it would be a small spot of flame moving leisurely across the sky.. and boy was I wrong!

Was alternating between glancing at the telecast and scanning the northern skies for a flame / smoke.. then I saw it. And for the first time in my life, said "holy sh!t" involuntarily.. The flame, a searing large one and the GSLV's pace was beyond blistering.. the rocket broke the haze cover a few seconds post lift off, and I barely managed 6 or 8 snaps before I lost track of the trail.

Such a majestic sight, and unfortunately most people did not care..

Will post some pics soon..

Sorry, if I sounded like a teen fanboy..
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Re: Indian Space Program: News & Discussion - Sept 2016

Post by SaiK »

thanks for sharing your observations sudhan, so vividly!
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Re: Indian Space Program: News & Discussion - Sept 2016

Post by Vamsi_V »

I live near Cape Canaveral and all the launches can be seen from my backyard. On a clear night stage seperation can be observed clearly. Unfortunately not many care here too.
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Re: Indian Space Program: News & Discussion - Sept 2016

Post by disha »

Vamsi31 wrote:I live near Cape Canaveral and all the launches can be seen from my backyard. On a clear night stage seperation can be observed clearly. Unfortunately not many care here too.
NASA lost space buffs after the space shuttle program ended, no further human flights till recently and nothing exciting other than some rovers on Mars. It is difficult to relate.

True space buffs are born, they are not created. They get a thrill even from a puny RLV launch.

---

Got call from my maternal uncle, asking will this "INSAT" show higher fidelity photos to air force for whooping a$$ of the neighbours? I had to explain to him that it is a comm satellite so that other teams within IAF and IAF/Army can collaborate over "space network", though the goal remains the same. He was pleased. I am sure he will come back with more questions.

On the telecast, looks like the Hindi commentator was from Hyderabad. The language appeared to be Hyderabadi Hindi. The comment "raakit taking selfie with sat" - yuck. Such commentators need to be fired.

DookhDarshan (DD) has one of the most shoddy coverage. Antrix should take over coverage and provide the feed to DD and other channels. Antrix is the commercial arm of ISRO and yes their brochure on ISRO.in was awesome with the panoramic photos. They need to spend and move into their own coverage.

Also the feed should be in Indian languages. I want a kid in Mizoram see this rocket launch and dream of contributing to the nation. Same from Jammu and same from a tribal hamlet in Orissa.
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Re: Indian Space Program: News & Discussion - Sept 2016

Post by Vamsi_V »

Yes inspiring people and creating a dream and hope for them is one of the most important outcomes of space exploration. ISRO should improve their coverage a lot in that regard.
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Re: Indian Space Program: News & Discussion - Sept 2016

Post by disha »

The post launch updates is a gold mine.

Here are the salient points:

Mission

1. 6th consecutive launch of GSLV.
Will stay longer in fleet and with improved capabilities., next GSLV MkII missions will have bigger payload volume

2. Mission handled during severe cyclone threat, lots of congrats to the ISRO MET dept.

3. Second (2nd) GSLV mission in same calendar year (2018) (first time and a long overdue goal)

4. Launched 25 th comm sat, life expectancy > 8 years

GSLV

1. 1.8 mtr longer.

2. Increased propellant loading in 2nd stage -> 37.5 to 40 tonnes

3. Increased propellant loading in Cryo -> 12 tonne to 15 tonne

4. Enhanced thrust value for cus, burnt to depletion to achieve super-synchronous orbit for GSAT 7A

Higher thrust - 13%
Longer burn duration
Indigenous material for thrust chamber.

5. Payload capacity increased from 1526 Kgs GTO to 2250 Kgs to Super-synch orbit (my take: GSLV Mk II can do 2500 Kgs to GTO)

6. Very precise injection. 2000 km more than expected apogee. Will help in longer life expectancy for Sat.

Satellite

1. Full steerable for regional coverage and spot beam for India - Gregorian antenna for 10 transponders and two services can be switched with each other seamlessly., solar panels successfully deployed within 100 s of injection.

Future: New challenge thrown by the chairman. -> 32 missions for next year.

====

My personal takes,

0. GSLV Mk II currently can easily do 2.5 to 3.0 tonnes to GTO (now).

1. GSLV Mk II is evolving as a work horse like PSLV. Also for specialized comm sats in 2000-3000 Kg range for dedicated customers - GSLV Mk III is an overkill and PSLV is not of much use. GSLV Mk II is the right launch vehicle.

2. SRB from GSLV Mk III should be put as first stage to GSLV Mk II. S139 should be retired and S200 should be put in its place. Strap-ons should be retained as it is. This will increase the diameter and the second stage can either be clustered or larger propellant loading. Same goes for CUS stage.

Currently the booster is 2.8 m dia with 3.4 m fairing. With a larger diameter 3.2 m booster diameter, the fairing can be increased to say 4.0 - 4.2 mtrs.

3. This will increase the payload capacity to 3.0 to 3.5 tonnes to GTO.
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Re: Indian Space Program: News & Discussion - Sept 2016

Post by Indranil »

I agree with you on several things here:

1. GSLV Mk2 as it was launched today could probably lift close to 2.35 tons to GTO. Also, going to super-synchronous orbit to save on fuel for subsequent orbit raising and inclination correction shows ISROs growing mastery on optimization. This technique will increase mission life of all future geostationary satellites launched from India soil.
2. Replacing the Vikas engines with HTVE on the L40 strapons and increasing fuel loading slightly would most certainly take launch capability to 2.7 tons to GTO.
3. You might remember, a year back, I had argued/agreed with you that a GSLV Mk2++ version with a 3.2 mtr core. It was pretty much on the lines of the LV you described above.

However, it would be much more easier to have a ULV based on GSLV Mk3 core:

Code: Select all

1. GSLV Mk3 core + 6 PSOM = LO mass (~230 tons) : payload (~1.3 tons to GTO)
2. GSLV Mk3 core + 2 S85  = LO mass (~350 tons) : payload (~2.25 tons to GTO)
3. GSLV Mk3 core + 2 S139 = LO mass (~510 tons) : payload (~3 tons to GTO) | Equivalent to the 3.2 mtr GSLV MK2++ config we both suggested.
4. GSLV Mk3 core + 2 S200 = LO mass (~640 tons) : payload (~4.5 tons to GTO)
This will bring costs down significantly. Increase launch rates. And be just one step away from our ULV plans: replacing the L110 stage with the semi cryo stage.
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Re: Indian Space Program: News & Discussion - Sept 2016

Post by Indranil »

Today, ISRO has all the building blocks to create all liquid LVs from 250-ton to 425-ton class using GSLV Mk3 core and 2-6 L40 strapons. But the focus is to consolidate all manufacturing efforts increasing launch rates of the existing LVs: PSLV, GSLV Mk2 and GSLV Mk3. The RnD focus is almost solely on GSLV Mk3 powered by SC200 stage and HSP. So, I don't think ISRO will focus on any other LV configs at the moment.
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Re: Indian Space Program: News & Discussion - Sept 2016

Post by disha »

Indranil wrote: But the focus is to consolidate all manufacturing efforts increasing launch rates of the existing LVs: PSLV, GSLV Mk2 and GSLV Mk3. The RnD focus is almost solely on GSLV Mk3 powered by SC200 stage and HSP. So, I don't think ISRO will focus on any other LV configs at the moment.
I agree with consolidating the manufacturing efforts and streamlining the building blocks and the LVs so that the buildings block come off an assembly line and the launch rates are both high at the same time lower cost.

However I disagree on the highlighted part. ISRO as it is, is fine tuning GSLV Mk II. Increased height (analyzing new design, since rocket length is increased), increased propellant loading and increased thrust and increased burn and achieve precision. Technically they did all of the above in almost a 6-8 months from the last GSLV Mk II launch. That is an amazing turnaround and hence ISRO can do more and must be made to do more R&D.

ISRO currently I feel is encumbered. Its budget should be straight way increased, and it should be 2x by 2020 and 8x by 2025 from the current year's budget. Also if ISRO's satellite monitoring and maintenance of satellite fleet needs to be split off to another agency, that will be just fine. That is anyway a distraction on ISRO.

Coming to the launch vehicles, ISRO should start ramping up on the following:

1. MethoLox engines incl. staged combustion metholox.
2. Heavy clustering. They should look at clustering 7-11 engines.
3. Restart/Recovery/Reuse. They can use RLV as a base. But should also look at designs that can recover upper stages. Including the spent CUS stage (it is doable).
4. In orbit docking/re-docking and transfer of fuel.

ISRO should aim for a family of cryo- engines., currently it has two. It should at least have 4 or 5. It should look at newer engine designs that give thrust in order of 2000 kN instead of the current 100-200 kN range. It can use its current CE 7.5/C 25 as clustered for single stage to sub-orbital test flights. Three C-25s clustered can do an easy task of a single stage to sub-orbital launch of a 3 person crew. This can be used for training crew. Or for giving 'astronaut' wings to friendly nations.

In future, ISRO should look at even more exotic propulsions like nuclear propulsion, electric & engine types like aerospike.

Point is, by 2040 ISRO must have a moon base and by 2050 it must be able to mine asteroids.
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Re: Indian Space Program: News & Discussion - Sept 2016

Post by Mort Walker »

sudhan wrote:Saw my first launch..from Chennai. Was having DD live telecast on one hand and my cam on the other.

Nothing prepared me for what was to come..

Given the distance from Sriharikota, I was thinking it would be a small spot of flame moving leisurely across the sky.. and boy was I wrong!

Was alternating between glancing at the telecast and scanning the northern skies for a flame / smoke.. then I saw it. And for the first time in my life, said "holy sh!t" involuntarily.. The flame, a searing large one and the GSLV's pace was beyond blistering.. the rocket broke the haze cover a few seconds post lift off, and I barely managed 6 or 8 snaps before I lost track of the trail.

Such a majestic sight, and unfortunately most people did not care..

Will post some pics soon..

Sorry, if I sounded like a teen fanboy..

To put it in perspective. The full thrust of an Airbus A380 is less than 1,400 KN. The PSLV is over 10,000 KN.
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Re: Indian Space Program: News & Discussion - Sept 2016

Post by Mort Walker »

disha wrote: In future, ISRO should look at even more exotic propulsions like nuclear propulsion, electric & engine types like aerospike.

Point is, by 2040 ISRO must have a moon base and by 2050 it must be able to mine asteroids.

Off-topic. Jab Pappu banega PM, then ISRO will be paying off the loans of the astroid miners. :mrgreen:
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Re: Indian Space Program: News & Discussion - Sept 2016

Post by Singha »

http://delhidefencereview.com/2018/12/1 ... perations/

article says 7A with its Ku band antennas will facilitate long range drone ops away from range of ground stations. maybe enabler for long range IOR ops by future Rustom2 / Mq4c / Guardian drones.

GAGAN gives us some independence from reliance on gps/glonass denial environments...though like all such systems it is prone to localized jamming that may happen from ships and land bases.
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Re: Indian Space Program: News & Discussion - Sept 2016

Post by symontk »

Rishi_Tri wrote:
Gagan wrote:As soon as the first stage was about to be shut off and just before the 2nd stage was ignited, Doordasha, stopped the live video of the rocket, and started showing ISRO chairman's face.
Bleddy DD walas are under ishtrict instructions not to show stage seperation or 2nd stage ignition (with the first stage still being lugged around and burning up due to the fire from the 2nd stage) on GSLV Mk2. That can be the only feasible explanation.
This time around, the DD camera did not do the schizophrenic up and down dance or the focus/unfocus nautanki just at the point of launch. Neither did they keep focusing on the dust cloud at the launch site, showing us nothing, until the rocket had climbed several kilometers in the air.

Sigh! DD will never graduate to show us stuff like, rocket has cleared the launch tower, stage separation.
Even the satellite separation video, was their camera focusing on the satellite feed on the main screen in control center.

Why, oh Why can't ANTRIX broadcast itself hain ji?
Why, oh why, can't they have onscreen telemetery hain ji?
Why can't they have a special hifi software to show us the launch data, have a high quality animation of the rocket hain ji?
Is it totally beyond ISRO and ANTRIX? Do these guys' telecast standards have to be stuck in the 1980s?

Finally why this undue secrecy, where it is not needed hain ji? India has the WORST TELECAST of all the top 5-7 space launching powers. This fact doesn't register with the powers that be at all? This doesn't cause any concern at all? GoI still stands behind the excuse that they invite tenders for broadcasters to come and cover the launch and only DD Chennai shows up - why can't ANTRIX and ISRO spend on high quality transmission, their own telescopes and various feed given to the television broadcast hain ji?

Being an individual who religiously watches their launches, and then ISRO related launches from Guyana, there is a big difference in the quality of the telecast

FWIW, both commentators are ex ISRO - who retired at fairly senior positions
:rotfl: DD will always remain DD. I am sure the only instruction would have been to show Mission Specialists' faces. Anyone with decent camcorder would have captured the stage separation from shores close to SHAR

But, all the same was perfect day to capture stage separation and falling off, and was waiting for it before the Mission Director's face came to occupy the screen for perpetuity. :rotfl:

Saw IAF folks also seated in audience.
ISRO has its own television for ages, is not being made available for public
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Re: Indian Space Program: News & Discussion - Sept 2016

Post by Bob V »

@kakarat, please do share your pics.
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Re: Indian Space Program: News & Discussion - Sept 2016

Post by prasannasimha »

ISRO is already working on electric propulsion and one of its sats has it. They are increasing the effectiveness. Also the scramjet work is going on. I am not sure what stage is the NEP. There was an old slide but not sure if any work is in progress. It was in conjunction with BARC.
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Re: Indian Space Program: News & Discussion - Sept 2016

Post by JayS »

sudhan wrote:
Sorry, if I sounded like a teen fanboy..
You are among the army of "teen fanboys" here.. :mrgreen:
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Re: Indian Space Program: News & Discussion - Sept 2016

Post by Kakarat »

I watched the launch from Pulicat and have photographed it with a 600mm lens. Will try to post the photos as soon as possible
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Re: Indian Space Program: News & Discussion - Sept 2016

Post by Haridas »

disha wrote:..... But should also look at designs that can recover upper stages. Including the spent CUS stage (it is doable).
Disha ji, Recovering CUS for only LEO is perhaps feasible, but with heavy penalty on overall throw weight, & overall payload fraction. I think you already know that.
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Re: Indian Space Program: News & Discussion - Sept 2016

Post by disha »

^ Haridas'ji. I have a different idea in mind.

One can put pop-out fins on it and what I call as "bloomers" (flaps that extend outward from a cylindrical stem), like petals on flowers around a stalk (though not that large petals and the stalk is a huge diameter cylinder)*

Goal is to use Earth's atmosphere to bleed out as much energy without destroying the stage. Particularly for CUS, it is technically in a GTO. Bringing it down without destruction is basically de-orbiting a stage. Huge challenge.

First step is to study re-entry of such stages and establish control laws. The stage itself can be made to use its body like an aerofoil.

So control laws that make stage stable (it will be spinning & tumbling) need to be developed and established. The fins and flaps can guide it to a manageable velocity and direct it to a down range where it can be splashed into sea using parachutes (or airbags). Even if it is not to be re-used, it can be restarted to establish data for restarts coming from a harsh atmosphere re-entry and sea recovery.

Just like the PSLV upper stage can be used for a short term sat payload, GSLV CUS must be used to test out stage recoveries.

Why GSLV CUS? Just because it is very tough. What we need is more data and more equations, even if the stage splashes in sea and is totally lost, what is the loss? And what is the cost in India? 4 PhD students, 16 Masters and 75 technicians and 2-4 professionals/professors/team leaders? I think Rs. 25 crore per year will suffice for such a team. And another Rs. 25 crore in material budget per year. One will see results in 1-2 years. We write off Rs. 600 crore electricity bills and lakhs of crores farm loans in matter of moments. I think I am just asking for 20% of that budget for R & D.

Again goal is stage recovery, but unlike spacex vertical landing. Since the goal is to bleed out as much energy as possible without destroying the stage. Once such control laws are in place, fuel for an additional burn of 10 secs should be fine. That is at most @2% extra fuel than the current propellant loading..

Why I am big on ISRO's capability? Here is the *only* space agency which has (almost) recovered successfully a booster mounted vertically launched winged object. Imagine the control laws in place that makes sure the launch is to the mission parameters? Speaking about it, when is the next RLV launch?

*Something like new shephard from blue origin.
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Re: Indian Space Program: News & Discussion - Sept 2016

Post by Prasad »

Next RLV test would be the heli dropped and runway landing test.
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Re: Indian Space Program: News & Discussion - Sept 2016

Post by prasannasimha »

https://www.youtube.com/watch?v=D7SRo2Xd6X4

GSLV launch tracking and onboard camera video
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Re: Indian Space Program: News & Discussion - Sept 2016

Post by prasannasimha »

The first orbit raising manoeuver of #GSAT7A satellite has been successfully carried out today by firing the Liquid Apogee Motor engine for a duration of 3895 seconds.
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Re: Indian Space Program: News & Discussion - Sept 2016

Post by Singha »

priceless. for the first time ever perhaps, colour video of the awe inspiring vented mesh interstage being engulfed in flame as second phase comes to life. and the 4 x meaty booster with first stage left behind.... payload fairing falling back at that screaming speed...
prasannasimha
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Re: Indian Space Program: News & Discussion - Sept 2016

Post by prasannasimha »

^There have been multiple videos of stage and interstage separation from quite some time.
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Re: Indian Space Program: News & Discussion - Sept 2016

Post by Haridas »

disha wrote:^ Haridas'ji. I have a different idea in mind.

One can put pop-out fins on it and what I call as "bloomers" (flaps that extend outward from a cylindrical stem), like petals on flowers around a stalk (though not that large petals and the stalk is a huge diameter cylinder)*

Goal is to use Earth's atmosphere to bleed out as much energy without destroying the stage. Particularly for CUS, it is technically in a GTO. Bringing it down without destruction is basically de-orbiting a stage. Huge challenge.

First step is to study re-entry of such stages and establish control laws. The stage itself can be made to use its body like an aerofoil. ......
Disha ji, Objects in that GTO orbit has at least 2 times more kinetic energy per gram than the full (> 18,000 km) range ICBM RV or Space Shuttle.

So recovering such large diameter object, with acceptable thermal Flux requires ablative large blunt surface that has natural (positive) stability (you know where is the Center of Mass for empty C25 stage is). So the problem is both in contraption and weight of what will become ablative blunt RV, and the very bad stability (still far from positive stabelity) even if magically one can fit the blunt surface on the spent C25 musharraf (the better end for best possible stabelity).

US Space shuttle style is the other extream way to make the max possible blunt surface on re-entry to get lowest possible thermal Flux that some material can bear without needing ablative method.

Temperature is the first killer issue, MaxQ will come later.

Petal bloomers don't stand a chance IMHO.
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Re: Indian Space Program: News & Discussion - Sept 2016

Post by Singha »

what is the distribution of cost between the 3 stages? is it worthwhile to try and retrieve the 1st core stage and its four strapons in a kind of reusable unified pack using spacex type stylebhai techniques ?
spacex claims to recover and reuse in 14 days as the eventual goal.
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