Indian Space Programme Discussion

Kakarat · Post by **Kakarat** » 05 Jan 2014 19:59

Comer · Post by **Comer** » 05 Jan 2014 20:52

chetan_chpd wrote:
is it because ISRO considers him as the same NASA did for carl sagan- a cosmic inspirational guide?

I don't know about ISRO, but when growing up he was one of the inspiration for me and my buddies at school to fall in love with science as he used to produce or appear in a program called Turning Point in Doordarshan

NRao · Post by **NRao** » 05 Jan 2014 21:09

India initiates steps to join International Space Station

arun · Post by **arun** » 05 Jan 2014 21:19

X Posted.

Cosmo_R wrote:Sorry but cannot resist:

"Why does India make fools of themselves messing in space technology? Stick 2 bollywood my advice."

Salman Taseer 2010

O! Quadrified one, you deserve an answer: we have our eyes on the stars. You and your ilk have theirs on mud.

The successful launch of the GSLV D5 was impeccably timed missing as it did Salman Taseer's death anniversary by a day.

Meanwhile moot to point out that while India has seen a satisfying riposte to Salman Taseer's jibe, Salman Taseer enjoys nothing of the sort with regard to his being Haji Bull Cutletted as his murderer Mumtaz Qadri continues to be very much alive.

Bade · Post by **Bade** » 05 Jan 2014 21:36

saravana wrote:
chetan_chpd wrote:
is it because ISRO considers him as the same NASA did for carl sagan- a cosmic inspirational guide?
I don't know about ISRO, but when growing up he was one of the inspiration for me and my buddies at school to fall in love with science as he used to produce or appear in a program called Turning Point in Doordarshan

Yash Pal started his career at the Tata Institute of Fundamental Research (TIFR), Bombay (now Mumbai), as a member of the Cosmic Rays group. He went to MIT for his Ph.D. and returned to TIFR, where he remained until 1973.

In 1972, the Government of India set up its Department of Space and embarked on an independent space programme. Yash Pal took charge as the first Director of the newly set up Space Applications Centre, Ahmedabad, in 1973. At the same time, he continued to be on the faculty of TIFR.

Yash Pal's administrative assignments at the Government level and beyond began with his appointment as the Secretary General of the Second United Nations Conference on Peaceful Uses of Outer Space (1981–82). He held the posts of Chief Consultant, Planning Commission (1983–84) and Secretary, Department of Science and Technology, Government of India (1984-1986), after which he was appointed Chairman, University Grants Commission (UGC) (1986–91). During his tenure as UGC Chairman, he advocated the setting up of Inter-University Centres funded by the UGC, on the model of the Nuclear Science Centre (now Inter-University Accelerator Centre), New Delhi. Institutions such as the Inter-University Centre for Astronomy and Astrophysics (IUCAA) emerged out of this vision.

He is one of the early founders from the Sarabhai era and PRL out of which SAC grew is the true cradle of ISRO.

Guddu · Post by **Guddu** » 05 Jan 2014 22:51

+1 Yashpal

I have known him as a kid, since his days at TIFR. He is one of the giants in Indian science and also well connected in Indian Gov circles for deciding how funding is to be disbursed.

disha · Post by **disha** » 06 Jan 2014 01:18

A Nandy wrote:Ok, I am no expert, but the strap-ons are lifting dead weight after that time. Maybe the first stage firing time can be increased to coincide with the end of the the strap-ons firing.

Not necessary. Even after the thrust from solid core is shut-off, until the acceleration followed by velocity imparted comes back to zero, one can hug the solid core.

The solid core is a fast burn motor, that is it gives a very large initial thrust sustained by the "boosters". The beauty of the design is the core is the "booster" and the surrounding strap-ons are "sustainers".

This was done specifically to ensure that the solid core is not ignited pre-maturely when the liquid sustainers cannot perform (or may underperform.

In so far of some 9 GSLV Launch programmes - the failures attributed due to the liquid straps are three. In first launch program, the liquid strap-on did not perform nominally (underperformed) and was caught and launch sequence aborted. In another failure (GSLV-F02), one of the liquid strap-on failed causing the rocket to be destroyed. That is like @25% failure (2 in @eight).

The caution thus of igniting solid "booster" followed by reliable "sustainer" is thus warranted.

What ISRO has done with the launch of GSLV is

* Master the cryogenic (given)
* Master "clustered" liquid propulsion (simultaneous ignition of 4 liquid-strapons)
* Scaling of liquid propulsion (the first stage of GSLV-MkIII is clustered large liquid engine)
* Validation of RLG INS - the precision on perigee is ~40 meter than expected and on apogee is some ~4 KM (this is @0.1% deviation at apogee!! or twisting it differently if ISRO were to target something at 32000 KM, it will be within 4 KM of the target - at 200 KM, ISRO will be 40M of target!! - others should dhoti-shiver here only).

At this stage, ISRO's path towards GSLV Mk III is clear.

PS: One more thing, ISRO should have a bullock cart to transport something to GSLV/PSLV and make a song and dance around it complete with photos and videos.

RKumar · Post by **RKumar** » 06 Jan 2014 01:19

Sriharikota to get third launch pad

The Indian Space Research Organisation (Isro) has lined up around 50 missions in the next five years.

To support these, the organisation was planning to set up a “high-tech” third launch pad at the Sriharikota space station, near Chennai, before 2016.

K Radhakrishnan, Isro chairman, said: “We require one more launch pad to carry heavy payloads and that would come up here in two years.”

The new launch pad would mainly support the Geosynchronous Satellite Launch Vehicle Mark-III (GSLV Mk-III), which would carry heavier satellites.

The Centre had approved setting up an assembly centre. A study was underway, he said, talking after the successful launch of the GSLV-D5 from the Satish Dhawan Space Centre at Sriharikota.

Officials added, the assembling facility and launch pad will come up in three square kilometer area, which is bigger then the measurement of the existing two launch pads, and it would require around Rs 500 crore of investment.

The new complex will provide complete support for the vehicle assembly, fueling, checkout and launch operations. Besides, it will have facilities for launching rockets meant for studying the earth’s atmosphere.

The complex will also have a new mobile pedestals, umbilical towers, emergency exits, ground escape system, crew ingress and egress systems, safety bunkers, material handling equipment and related electrical systems, said Isro.

Vipul · Post by **Vipul** » 06 Jan 2014 06:59

'Naughty boy’ GSLV makes Isro parents proud with successful blast-off.

Suddenly on Sunday, cryogenics — the study of extremely low temperatures and their effects — was the hottest topic at India's spaceport in Sriharikota. After more than 20 years of toil, India has been able to successfully fire an indigenous cryogenic engine to launch a GSLV rocket, a crucial milestone for future projects including Chandrayaan-2 and the manned mission.

"Today the naughty boy has become obedient," said S Ramakrishnan, director of the Vikram Sarabhai Space Centre, referring to the many failures that preceded the moment of triumph. Mastering cryogenic engine technology which involves using liquid hydrogen at -253°C and oxygen at -183°C has been a tricky feat.

So far, only US, European Space Agency, China and Japan have succeeded. The story of India's struggle with the cryogenic engine is linked to the collapse of the erstwhile Soviet Union in 1991, the year in which India was to receive the technology from the Russians. The agreement was Soviet Union would transfer the technology to India and provide three cryogenic engines.

However, after the disintegration of USSR, Russia went back on the pact in 1993 and, under pressure from US, refused to part with the technology. But it agreed to provide four more fully made cryogenic engines, taking the number of such engines in India's kitty to seven.

The man who then headed Isro's cryogenic project, Nambi Narayanan, managed to bring in crucial components of the engine from Russia without drawing US attention. When Air India refused to fly in the hardware fearing US embargoes, the Isro team used Russia's Ural Airlines to transport it in three consignments.

But Narayanan soon found himself in prison following what came to be known as the Isro spy case. His arrest and the espionage charges damaged the team's morale. "There is no doubt the foisted case destroyed the organization's morale," Narayanan said. "Otherwise we would have had the cryogenic engine ready by 2001."

In 2010, Isro thought it was finally ready. On April 15, GSLV-D3 lifted off carrying GSAT-4, but the engine failed 800 milliseconds after ignition. For the next launch, Isro decided to use one of the last two Russian engines, but again tragedy struck when liquid fuel boosters failed.

GSLV remained jinxed as another attempt to launch it using an indigenous cryogenic engine had to be aborted in August 18, 2013 after a leak was detected in a liquid fuel tank.

Radhakrishnan said: "In the last three years, we have done 45 different tests to ensure the indigenous engine is flawless. Today's launch has come as the biggest reward."

partha · Post by **partha** » 06 Jan 2014 07:11

disha wrote:
At this stage, ISRO's path towards GSLV Mk III is clear.

Not yet. GSLV Mk III will use a CE 20 cryo engine which employs the next gen tech (gas generator cycle) compared to CE 7.5 (staged combustion cycle) which was used yesterday. CE 20 is still a work in progress. 2014 will see test launches of GSLV Mk III without the cryo stage. 2015 is when it is expected to be tested with CE 20.

member_28108 · Post by **member_28108** » 06 Jan 2014 07:18

Not to deny that the gas generator cycle is complex but the staged combustion cycle is actually more complex compared to te gas generator cycle and is cheaper but less efficent. I ahd posted how the US is also shifiting to gas generator cycle due to cost considerations for their Atlas and other rockets.

disha · Post by **disha** » 06 Jan 2014 08:32

partha wrote:
disha wrote:
At this stage, ISRO's path towards GSLV Mk III is clear.
Not yet. GSLV Mk III will use a CE 20 cryo engine which employs the next gen tech (gas generator cycle) compared to CE 7.5 (staged combustion cycle) which was used yesterday. CE 20 is still a work in progress. 2014 will see test launches of GSLV Mk III without the cryo stage. 2015 is when it is expected to be tested with CE 20.

Comparing Gas Generator (GG) Cycle with Stage Combustion cycle in generational terms IMVHO is plain wrong.

If complexities define the generation then Stage Combustion Cycle is "next gen". Stage Combustion is more complex.

If high specific impulse (more efficiency) define the generation then Stage Combustion Cycle is "next gen". Stage Combustion is *more* efficient!

So why is GSLV Mk III which is a "next gen" design using "older gen" Gas Generator?

Answer is in the flight profile and thrust requirements.

Basically SC Cycle runs hotter, faster and higher - that is higher temperatures, faster turbopump cycles (particularly the pre-combustion that drives the turbine has to run faster to not have a chamber back pressure coming in from the nozzle)., This creates higher chamber pressure and hence better efficiency.

GG engines run cooler. That allows one to have a design with a higher nominal thrust but a lower impulse (like a truck vs. a car).

Given that ISRO has mastered fabrication, testing and flying SC Engines, its path is clear towards larger engines incl. GG cycles. With this test, ISRO does not have to always look over its shoulders and can confidently go towards bigger and bolder designs.

rajsunder · Post by **rajsunder** » 06 Jan 2014 11:01

partha wrote:
disha wrote:
At this stage, ISRO's path towards GSLV Mk III is clear.
Not yet. GSLV Mk III will use a CE 20 cryo engine which employs the next gen tech (gas generator cycle) compared to CE 7.5 (staged combustion cycle) which was used yesterday. CE 20 is still a work in progress. 2014 will see test launches of GSLV Mk III without the cryo stage. 2015 is when it is expected to be tested with CE 20.

prasannasimha wrote:Not to deny that the gas generator cycle is complex but the staged combustion cycle is actually more complex compared to te gas generator cycle and is cheaper but less efficent. I ahd posted how the US is also shifiting to gas generator cycle due to cost considerations for their Atlas and other rockets.

from wiki about staged combustion cycle engines

The turbines run cooler in this design since more mass passes through them, leading to a longer engine life and higher reliability. The design can provide higher chamber pressures and therefore greater efficiency. An intrapropellant turbine seal is also eliminated. Full gasification of components leads to faster chemical reactions in the combustion chamber and, as compared to the partial staged combustion cycle, it results in an increase of specific impulse up to 10–20 seconds (e.g., RD-270 and RD-0244).

more about the staged combustion cycle

dinesh_kimar · Post by **dinesh_kimar** » 06 Jan 2014 11:30

Some of the older satellites are dead junk , and contribute to debris in space. We can test an ASAT , which wont harm us in form of sanctions, and which is anyway long overdue.

Bade · Post by **Bade** » 06 Jan 2014 18:06

There is difference between one dead satelllite in orbit versus the same dead satellite broken into a thousand small pieces in orbit. Now everyone will have to track most of the large pieces at least and hope the smaller ones (which are harder to track) won't do a self-hit on our later launches.

SSridhar · Post by **SSridhar** » 06 Jan 2014 18:26

dinesh_kumar wrote:Some of the older satellites are dead junk , and contribute to debris in space. We can test an ASAT , which wont harm us in form of sanctions, and which is anyway long overdue.

We will contribute to more space debris.

dinesh_kimar · Post by **dinesh_kimar** » 06 Jan 2014 18:37

The US ASAT test of SM3 from the Aegis ship, how was that managed? (Somehow test the ASAT option, thats the idea)

Indranil · Post by **Indranil** » 06 Jan 2014 22:12

one kuschen. How about taking out a simulated satellite?

sanjaykumar · Post by **sanjaykumar** » 06 Jan 2014 22:20

One only has to demonstrate control over positioning and not destroy anything. Thus if it is announced that an Agni iv will intercept the orbital path of a given satellite with a one second delay to the physical satellite, that will constitute adequate demonstration of capability.

Indranil · Post by **Indranil** » 06 Jan 2014 22:40

That is obvious, but 1 second is too much tolerance. But why not show case it. Biggest proof to oneself and others.

disha · Post by **disha** » 06 Jan 2014 22:48

Or a better demo, capture a junked satellite and bring it down.

- A space debris is removed
- Shows supreme mastery over several areas of technology, design and control

And finally will prove my ASAT is better than your ASAT. Your ASAT will create space debris, my ASAT will capture your satellite and de-orbit it burning it in atmosphere and with fair warning will capture your ASAT as well before it can do damage! What will we call an anti-ASAT - AASAT?

svinayak · Post by **svinayak** » 06 Jan 2014 22:54

Capture a GeoSat?

Comer · Post by **Comer** » 06 Jan 2014 23:00

Anybody followed/following this reddit AMA by ISRO scientists?

http://www.reddit.com/r/india/comments/ ... swer_your/

EDIT: Just missed them by few minutes. If you have some questions to ISRO guys post them there. They may come back tomorrow to answer them.

pankajs · Post by **pankajs** » 06 Jan 2014 23:23

I think now is the right time for ISRO to fully outsource PSLV to Indian industry.

partha · Post by **partha** » 07 Jan 2014 02:42

saravana wrote:Anybody followed/following this reddit AMA by ISRO scientists?

http://www.reddit.com/r/india/comments/ ... swer_your/

EDIT: Just missed them by few minutes. If you have some questions to ISRO guys post them there. They may come back tomorrow to answer them.

Thanks for sharing. That was a good AMA.

Prem Kumar · Post by **Prem Kumar** » 07 Jan 2014 03:11

disha wrote:Or a better demo, capture a junked satellite and bring it down.

- A space debris is removed
- Shows supreme mastery over several areas of technology, design and control

Or how about an ASAT missile getting close enough to a dead satellite & delivering a box of flowers using a directional warhead? This flower box will attach itself to the satellite. Will demonstrate capability & responsibility

saip · Post by **saip** » 07 Jan 2014 03:22

You can do streaming video too while delivering the flowers?

Bade · Post by **Bade** » 07 Jan 2014 06:08

Well if you can land on a small size asteroid, you will have demonstrated the capability. It is science too and something only the US has done so far. ( JHU APL mission if I recall)

If you want to do some fireworks and really take a sat out with a kinetic kill, it is better to do it in lower than LEO used by many working satellites. It is easier to kill a stable orbit object compared to one which is degrading faster, which means a greater challenge. This has better PR value as you can claim did not want it to land as a big piece on a human settlement. And the smaller pieces will burn up in the atmosphere anyway.

sanjaykumar · Post by **sanjaykumar** » 07 Jan 2014 06:33

That is obvious, but 1 second is too much tolerance. But why not show case it. Biggest proof to oneself and others.

In fact the temporal delta is not relevant, the critical part is calling it a priori. That is, even if it is 20 minutes, the prediction should be accurate and precise enough to demonstrate inevitable impact. The orbital interception must be seen to perform according to prediction.

PratikDas · Post by **PratikDas** » 07 Jan 2014 07:22

Taking inspiration from Sputnik, launch two ASAT vehicles against a junk satellite, one that intersects X m ahead of its orbit and one that intersects the same X m behind. Demonstrate fuse timing by having both ASAT transmit their own simple monotonic wave throughout their flight but change the phase at the exact moment the fuse is meant to go off. Advertise the frequencies for the two ASAT in advance.

krishnan · Post by **krishnan** » 07 Jan 2014 17:06

http://www.reddit.com/r/india/comments/ ... swer_your/

We are three ISRO scientists here to answer your questions -AMA[Verified] (self.india)

submitted 22 hours ago* by ISROredditors

-Obligatory disclosure: All answers are UNOFFICIAL and our views are not the organisation's views. AMA!

{EDIT} Thank you guys (and girls!) We had a great time, but we need to sign off for now.

We'll try to answer some more questions tomorrow. Goodnight

Don't forget to like the official ISRO page at https://www.facebook.com/isroofficial

{EDIT 2} Looks like we have got quite the attention today. Even though we have been passively answering questions all day (One of us is on leave), there are lots of unanswered questions. We have decided to have a session today too, 7pm (IST) onwards. Do spread the word and keep the questions coming. Cheers!

vdutta · Post by **vdutta** » 07 Jan 2014 19:03

saravana wrote:Anybody followed/following this reddit AMA by ISRO scientists?

http://www.reddit.com/r/india/comments/ ... swer_your/

EDIT: Just missed them by few minutes. If you have some questions to ISRO guys post them there. They may come back tomorrow to answer them.

Thats great reaching out by ISRO.

Lets inundate the comments section for putting cameras on board the rockets at seperation stages and to redo the website with more pics.

That gotta make it to the right people if we have enough requests

Comer · Post by **Comer** » 07 Jan 2014 22:38

^^ Guys they are online and answering questions now.

Sridhar · Post by **Sridhar** » 08 Jan 2014 03:53

What is the building in the background in this picture?

It looks like a second Vehicle Assembly Building, but I thought it received financial sanction only last year.

Varoon Shekhar · Post by **Varoon Shekhar** » 08 Jan 2014 07:05

^
So Sridhar, did ISRO have only one vehicle assembly building all these years, including when they had 3 launches per year, starting in 2007? Anyway, good development if a 2nd one is being built. It shows that they are definitely anticipating an increase in launches per year, in the coming years.

symontk · Post by **symontk** » 08 Jan 2014 07:29

The VAB near to GSLV is the second launch pad and the one in the background is first launch pad

disha · Post by **disha** » 08 Jan 2014 08:35

Sridhar wrote:What is the building in the background in this picture?

It looks like a second Vehicle Assembly Building, but I thought it received financial sanction only last year.

I have pointed this out earlier with the 3rd launch pad., ISRO submits its project plans to DoS and starts some of the projects which it knows will be approved with its non-plan budget or something like that. Designs are finalized, pvt. contractors sought out, indents are placed and work also gets started.

Somewhere near 2/3rd completion the budget gets approved and ISRO ends up finishing the project on time and on budget! Sometimes in record time.

This is actually a case of good parallelization, not that I am complaining. Same with the 3rd launch pad. And they will fire a sub-orbital GSLV Mk-III to test the entire process and the launch pad and also "wind tunnel" testing of the real thing in real wind load conditions. Budget for the 3rd launch pad was approved only recently.

BTW, the 3rd launch pad seems to be the 5th launch pad., the launch pads of SLV/ASLV seems to be left alone untouched.

Bade · Post by **Bade** » 08 Jan 2014 08:52

If you check google maps there are at least two square pill boxes, one on the straight line along this alignment and another close to the straight line between these visible buildings (VAB). The former pill box has two visible holes from top view, maybe that is meant for the Mk-3 launch. But then the spacing between the two VABs is not much and how can there be a launch pad situated in that tight space ? It does not make sense.

There is also another independent launch pad and annotated as the first launch pad which is north of these two. Is this one the PSLV launch pad ?

rahulm · Post by **rahulm** » 08 Jan 2014 08:53

I think Falcon uses LOX/Kerosine and not LOX/LH2. Soyuz and Saturn also used this combination. You don't need LOX/LH2 for medium to heavy lift capability to GTO.

There is a school of thought that says ISRO could have realised the GSLV about a decade or so earlier if it had followed the LOX/Kerosine route but instead choose to single mindedly focus on the LOX/LH2 route. There was discussion on BRF about this and Umrao John had plenty to say. May be archived.

ISRO has since re-started the LOX/Kerosine programme.

SSridhar · Post by **SSridhar** » 08 Jan 2014 09:14

symontk wrote:The VAB near to GSLV is the second launch pad and the one in the background is first launch pad

That's correct. In the first launchpad, the VAB moved out whereas in the second launch pad, the vehicle moves out on a pedestal after assembling and prior to launch.

BTW, the PIB press release of September 2013 talks of 42 months for the completion of the second VAB. In reality, it is the third VAB but it is called the second VAB because the VAB nomenclature did not apply to the first launch pad.

In addition a third launch pad is being talked of.