Indian Space Program: News & Discussion

[SSridhar]

ISROs ambit or mission is to support India’s space requirements - be it satellites or launches. Commercial launches are an after thought. Yes, it makes a tidy side income with these launches, but that’s not the main purpose. This is opposed to SpaceX which is an out and out commercial venture that must make a profit and reduce costs.

I agree that booster reuse is required especially if we start making higher impulse engines. But is it as much a priority for ISRO given its budget constraints and other programs?

Tanaji, Yes that was the ambit when we launched the space mission when everyone ridiculed us as to why a poor nation should aspire for space. We said space would improve development goals of India and we were not interested in sending crewed spaceflights as we needed only remote sensing & communication satellites. And, we did exactly that for several decades and rightly so too. Then we had to have dedicated military satellites, GSAT-7 series. TES, RISAT, EMISAT, IRNSS & NAVIc happened. We needed to send CY1 (and Pres. Kalam rightly advised crash-landing on the moon to stake our claims if it came to later colonization, real-estate claims etc) and here we are at Mangalyaan & CY2 & 3. We are sending Aditya to L1 point of ES. More such astronomical payloads are being planned. We have bilateral collaboration with Japan for landing on the moon and joined the Artemis. Our Gaganyaan would happen shortly. We plan to have our own space station. Our lifting capacity to LEO & GTO need to increase including for various other reasons. We have to develop docking & robotic arm technologies. We require Rendzvous and Proximity Operation (RPO) capabilities. There are various needs for these including the security angle, space-debris removal, refueling for life extension etc. Today, SSLV is outsourced and PSLVs too. There is a big demand for these classes of vehicles which should increase our space economy so that we can reinvest for other advances in our space activities. The estimate is that our space economy would be USD 15B by 2025-2026. In essence, the frugal objectives with which ISRO started have already broadened both because of internal and external factors. Every aspect of space activity is assuming significance, for one reason or another, and nothing can any longer be neglected.

[SriKumar]

^^^ I agree with the thrust of this argument. Any major step in space technology takes a decade, give or take....so the time to start is now to mature a technology in 2033 (whatever the technology might be). In principle, I do agree, for example that maybe more satellites should be launched insted of gaganyaan but India needs to rid itself of the shortage mind-set from now on, given that the economy is growing, and at this pace may become next only to US and China by 2030's. I think the world is getting this message. I've not seen too many (or any) articles 'saying 'India ij going to moon but no toilets on earth', or, 'X billion live under a dollar a day so India should moon the moon instead of landing on it', unlike when CY2 was launched. Then UK's economy was larger than Inida's. Not any more. The primary concern in a human space flight is reliability. Cost, optimization, jazz, sophistication, hi-tech etc. come second to it. Imagine what would happen if the mission failed with a loss. Unlike CY2, there would not be another mission in 3 years....or much more.

[SSridhar]

The primary concern in a human space flight is reliability, in my view. Cost, optimization, jazz,sophistication, hi-tech etc. come second to it.

Of course, nobody tries immature technologies on critical projects like Gaganyaan. They are not needed too as they would be rare events. The bread-and-butter is satellite launches and here is where optimization would benefit. As Tanaji was saying, cost of access to space is coming down rapidly and we have to be competitive too for LEO & GEO spaces. As you said, these technologies require some years to mature. I recall ISRO Chief Sivan speaking about docking four years back using the 4th stage (POEM project) and also about a robotic arm.

[sanman]

NASA & DARPA are collaborating to develop DRACO (Demonstration Rocket for Agile Cislunar Operations), a spacecraft powered by a nuclear thermal engine, which uses hydrogen as propellant.

(first 6.5min are the relevant part)



DRACO is an updated version of NERVA, which was America's old nuclear thermal rocket idea pursued back in the 1950s-1960s.

https://en.wikipedia.org/wiki/NERVA

What would it take for India to develop a nuclear thermal rocket?

Let's first imagine we develop a reusable launcher (NGLV), and then on top of that we integrated an upper stage powered by a nuclear-thermal engine which could initially operate as an orbital space tug and then later be upgraded to function as an Earth Departure Stage.
Imagine eventually using such a nuclear thermal rocket stage to dock with a spacecraft in LEO and carry it all the way to a landing on the Moon's surface, and then later return back to LEO again. Hydrogen propellant could be manufactured from lunar water ice to support such operations.

BARC is now developing RTGs (Radioisotope Thermal Generators) for ISRO, which can be used to power electric ion-propulsion thrusters.
But these devices derive energy from radioactive decay, and are still not quite at the energy level of nuclear power reactors.

India had already developed a Compact High-Temperature Reactor, which could possibly be operated on submarines and used to efficiently break down water into hydrogen and oxygen. If India could adapt this reactor design for use in the lunar environment, perhaps it could be used on the Moon to manufacture hydrogen propellant from lunar water ice.

https://www.business-standard.com/artic ... 086_1.html

See page 7:
https://www-pub.iaea.org/MTCD/Meetings/ ... gramme.pdf

Note that India's Compact High Temperature Reactor (CHTR) uses the Thorium fuel cycle. Also note that Thorium is abundantly available in the surface regolith of the Moon and Mars.
NASA's 2001 Mars Odyssey mission had detected large amounts of Thorium in the Martian surface soil:

https://mars.nasa.gov/odyssey/gallery/l ... 04257.html

[arvin]

https://www.financialexpress.com/lifest ... s/3192307/

PSLV successfully launched DSSAR and other 6 satellites.

[SSridhar]

It was a dedicated launch for Singapore.

The PS4 stage would be deorbited as a responsible spacefaring nation to reduce orbital debris.

In July 2022, ISRO set up a comprehensive SDA (Space Domain Awareness) facility known as ISRO System for Safe and Sustainable Operation (IS4OM) for ‘safeguarding Indian space assets against space environmental hazards, to pursue the related R&D activities, and also to contribute to awareness raising on the long-term sustainability of outer space activities’. The Long-term Sustainability Working Group under the UN Office for Outer Space Affairs (UNOOSA), Inter-agency Space Debris Coordination Committee (IDAC) requires such measures but are generally ignored by most.

[sanman]

Interview with Dr Mylswamy Annadurai

[disha]

Why are we still using maraging steel for the S200 solid rocket boosters? Can composite rocket motors be developed for the same? We have now have composite rocket motors for the Agni-5. If the S200 can be made with composites, the weight would reduce and the obvious benefit would be a higher payload capacity.

Mody'ji, several posts might have explained it better. Here is my attempt:

The use case of a ballistic missile vs that of a launch rocket is different. For example, the "payload" of a ballistic missile absolutely has to come back down. Meanwhile the "payload" of a launch vehicle absolutely has to *not* come back down at all!

And that drives several aspects of the system. So a missile requires an efficient booster to throw the upper stages into a particular "window". Job done and damn the cost. For strategic missiles like Agni, the idea is that it gives Agony in mind of the opponents. Again cost is *not* the key here. More importantly, launches of such strategic missiles are fewer and far between (except when it is used, which hopefully is never). Again cost is not the key here. One important aspect here, the strategic payload is constant. Its size & weight is more or less constant. India can afford to spend USD 1 Billion to have an HMX based propellent in a carbon composite stage. DRDO can spend another $1Bn if necessary to come up with Agony+++. Do note that the first stage of Agni-V is maraging steel. And burns <90s! And the upper composite stages came into being only in Dec' 22 test.

That is not the case for a launch vehicle booster. It has some additional responsibilities. Like take help from additional boosters based on the launch requirements. Yes the orbital parameters have to be precise and all that., but the payload changes for each class of the payload and sometimes different categories of payloads has to be packed in. This means the booster *system* has to be flexible, reliable and cost effective.

ISRO has to churn out solid boosters in an assembly line mode. At this point the commonality of the input material is important. The same M250 Maraging steel is used in gears, fencing swords, rifle pins etc etc, so the input source is widely available and more it is consumed, the more it gets cheaper (since it is mass produced).

Take a look at this document: https://web.archive.org/web/20130311191 ... EST-01.pdf

If you notice, there are several hookups to the S200 boosters. On the side it needs hookups for SITVCs and also hook up into the core of the LVM. Here I will digress a little. I was making this model rocket and put in a composite E motor that generated some ~40 N-s thrust. All under 1s. Countdown goes to zero, ignition is initiated, and before the rocket clears the launch pad, the engine pops out of the front of the rocket and launches several tens of feet into air and thankfully tumbles down harmlessly. This is all in under <2-3 seconds. What happened? I put a very powerful engine into a stage that could not hold the engine down. The rocket would have been more efficient (~40 N-s is lot of energy).* Put it this way, You do not want your launch rockets to behave like Cheeni rockets where the stages fall off at the wrong time and kill innocents.

Point is, you need launch rails, pad holdups, other integrations which are too many to enumerate here that can sustain heavy loads and stresses across several temperature gradients. This is already designed and tested as units and complete integration testing is done and a long supply chain tail is created to make the launches both operational and sustainable.

An example is PSLV. Conceptualized in 1970s, designed and developed in 80s and is still in use. You have different variants of the launch vehicle. Core alone. XL etc. One can now easily project into a decade and come up with supply chain orders. You can also project how many launches you can do and schedule your customers accordingly.

So the major point is, updating your booster launch to composite may make the payload increase say by a 10% factor. But at what cost? If I can launch 1000 kgs at $1 per Kg, then I have the biggest winner. Compared to someone who launches at 10 tonnes but at $10,000 per kg! Of course you do not want your payloads to be too small. We are beyond the SLV/ASLV stage and even they have utility.

Talking about costs, the SpaceX starship went from composite to steel. Did they not study the mass fraction before going back to steel?

The number you are looking for is called payload fraction. And payload fraction at reliability, cost and versatility. That is what SSLV is all about.

There is an unhealthy obsession that bigger payload capacity makes your space program advanced. Bigger payload capacity helps, but that is not the sole criteria of being ahead in a space program. So comparisons of rockets just based on payload capacity is like juveniles comparing certain organs down under.

At the same time Indian space program has to evolve. But prior to that I think the Indian populace has to evolve. More on that later.

*PS: It took me 5-6 months to figure out how to contain a 40 N-s rocket motor and test it so that the next launch was perfect. Had to write some waivers and get additional insurance.

[sanman]

The use case of a ballistic missile vs that of a launch rocket is different. For example, the "payload" of a ballistic missile absolutely has to come back down. Meanwhile the "payload" of a launch vehicle absolutely has to *not* come back down at all!

...

So the major point is, updating your booster launch to composite may make the payload increase say by a 10% factor. But at what cost? If I can launch 1000 kgs at $1 per Kg, then I have the biggest winner. Compared to someone who launches at 10 tonnes but at $10,000 per kg! Of course you do not want your payloads to be too small. We are beyond the SLV/ASLV stage and even they have utility.

Talking about costs, the SpaceX starship went from composite to steel. Did they not study the mass fraction before going back to steel?

Stainless steel was chosen for SpaceX Starship because it's much cheaper to develop with, compared to lightweight carbon composites. They did originally try to manufacture with carbon composites, producing some large test articles like large carbon composite tanks.

But a key criteria in selecting the Stainless Steel was its great strength improvements at cryogenic temperatures.
Neither PSLV nor SSLV have cryo-propellants, and even LVM3 only uses them for upper stage.

The number you are looking for is called payload fraction. And payload fraction at reliability, cost and versatility. That is what SSLV is all about.

There is an unhealthy obsession that bigger payload capacity makes your space program advanced. Bigger payload capacity helps, but that is not the sole criteria of being ahead in a space program. So comparisons of rockets just based on payload capacity is like juveniles comparing certain organs down under.

At the same time Indian space program has to evolve. But prior to that I think the Indian populace has to evolve. More on that later.

*PS: It took me 5-6 months to figure out how to contain a 40 N-s rocket motor and test it so that the next launch was perfect. Had to write some waivers and get additional insurance.

I hope we get into reusable rocket hardware, like current ISRO chairman S Somnath wants us to. I really like S Somnath a lot and am rooting for him, because I feel he's a very capable person, and this transition to reusability (and private sector) is a very big deal.

Once we start reusing the hardware and amortizing its cost across multiple launches, then it becomes much more justifiable to invest in using superior construction & materials like carbon composites, etc.

Some of reusable NGLV's hardware is going to be tested even under Gaganyaan program budget, as part of in-flight abort testing.

[neerajb]

Elon said the following on usage of stainless steel by Spacex in starship instead of Aluminium/carbon fiber:

Carbon Fiber Composite:
1. Costs 130$/kg
2. For Starship needed a huge autoclave (9 meters dia, 70 meters length)
3. Composites are porous to hot gases, needs an inner liner which adds to cost, weight and complexity.
4. Resin used in composites is flammable at high temperatures.
5. Strength is half of steel at cryogenic temperatures.
5. They were not making good progress fabricating using carbon fiber.

Aluminium Lithium Alloy:
1. Costs 40$/kg
2. Highest strength/weight
2. Hard to weld, friction stirr welding

Stainless Steel:
1. Costs 4$/kg
2. Strength almost as good as carbon fiber
3. Very good strength properties at cryogenic temperatures
4. Easy to weld, attaching anything to it is super easy, just weld it.
5. No need to paint
6. Most importantly, Stainless steel is good even at 800 or 1000 degrees. So a very lightweight heat shield is sufficient for reentry. Carbon fiber or aluminium needs heavier heat shields due to lesser base material heat properties. Effectively stainless steel vehicle is lighter overall as compared to other two.

[sanman]

Elon said the following on usage of stainless steel by Spacex in starship instead of Aluminium/carbon fiber:

Carbon Fiber Composite:
1. Costs 130$/kg
2. For Starship needed a huge autoclave (9 meters dia, 70 meters length)
3. Composites are porous to hot gases, needs an inner liner which adds to cost, weight and complexity.
4. Resin used in composites is flammable at high temperatures.
5. Strength is half of steel at cryogenic temperatures.
5. They were not making good progress fabricating using carbon fiber.

Aluminium Lithium Alloy:
1. Costs 40$/kg
2. Highest strength/weight
2. Hard to weld, friction stirr welding

Stainless Steel:
1. Costs 4$/kg
2. Strength almost as good as carbon fiber
3. Very good strength properties at cryogenic temperatures
4. Easy to weld, attaching anything to it is super easy, just weld it.
5. No need to paint
6. Most importantly, Stainless steel is good even at 800 or 1000 degrees. So a very lightweight heat shield is sufficient for reentry. Carbon fiber or aluminium needs heavier heat shields due to lesser base material heat properties. Effectively stainless steel vehicle is lighter overall as compared to other two.

That's a great summary.

It's also useful to bear in mind that Musk was looking for materials that will stand up to lunar or martian return velocities, which have the highest thermal & mechanical loads during re-entry.

Do you think it would be practical / feasible for India to go in for a similar approach for eventually building its own reusable very heavy lift vehicle?
Such an approach would presume a cryogenic propellant combo, and we are in the process of developing our own methane-LOX engine.

If we decide to go with robotic AI-led exploration of Moon & Mars, then we can fall back on the slow spiral out from Earth, like we've been doing with Chandrayaan & Mangalyaan missions. It's only for human-led exploration with crewed missions that we need to go in for direct pointA-to-pointB flight trajectories with higher fuel consumption.
And notice that NASA/DARPA are now going in for nuclear thermal propulsion as their method of choice for interplanetary travel.

So could we likewise develop our own nuclear engines for interplanetary spaceflight?
Perhaps we could first look at nuclear-electric plasma propulsion before nuclear thermal propulsion.

[csaurabh]

Elon said the following on usage of stainless steel by Spacex in starship instead of Aluminium/carbon fiber:

Carbon Fiber Composite:
1. Costs 130$/kg
2. For Starship needed a huge autoclave (9 meters dia, 70 meters length)
3. Composites are porous to hot gases, needs an inner liner which adds to cost, weight and complexity.
4. Resin used in composites is flammable at high temperatures.
5. Strength is half of steel at cryogenic temperatures.
5. They were not making good progress fabricating using carbon fiber.

Aluminium Lithium Alloy:
1. Costs 40$/kg
2. Highest strength/weight
2. Hard to weld, friction stirr welding

Stainless Steel:
1. Costs 4$/kg
2. Strength almost as good as carbon fiber
3. Very good strength properties at cryogenic temperatures
4. Easy to weld, attaching anything to it is super easy, just weld it.
5. No need to paint
6. Most importantly, Stainless steel is good even at 800 or 1000 degrees. So a very lightweight heat shield is sufficient for reentry. Carbon fiber or aluminium needs heavier heat shields due to lesser base material heat properties. Effectively stainless steel vehicle is lighter overall as compared to other two.

This list is an oversimplification to say the least or even plain wrong in parts.

Cryogenic tanks are well insulated, there is no issue in using CFRP composite ( infact newer ISRO cryo tanks are CFRP design )
Composites need inner liner, steels need an inner liner as well (typically nitrile/EPDM rubber for solid motors)
Resin is flammable at high temperature, thats why you use ceramic matrix along with the carbon fibre (CMCs) for high temperature parts - like Carbon Carbon, Carbon -SiC . Newer versions of jet engines are using CMCs for turbine blades rather than superalloys.

Stainless steel strength almost as good as carbon fibre? On what grounds? Maybe volume wise, but in weight CFRP parts are often 1/3 to 1/5 the weight of an equivalent strength steel part. Some numbers, Stainless 304 tensile strength is 515 MPA, yield at 205 MPA , whereas even a low grade carbon fibre (Not Aerospace grade, just commercial) composite will have over 2000 MPA tensile strength..
Aluminium Lithium or Aluminium Boron MMCs (Metal matrix composites) have better properties than conventional Al alloys but aren't used that much for practical applications (As compared to standard aluminium alloys). Also, no, their str/weight won't be higher than CFRP.

As far as costs are concerned, raw material itself is not a large part of the costs in aerospace. A modern airliner costs around $300 million, $10 million of that would be carbon fibre. Would it be that much cheaper to make it in aluminium ? Or rather go with a lighter composite aircraft -> less weight = more fuel saved -> save money that way.

I think there is a good reason for ISRO not to use much carbon fibre, that is because it is currently imported, and there are restrictions around it.
So if a supply chain has been established around maraging steel, no need to disrupt that for small advantages.

Elon Musk has crazy ideas to send hundreds of people to Mars on Starships, which are not logistically feasible anyway no matter whether it is made of steel or carbon fibre or unobtanium. So it's hard to take any of that reasoning seriously. In fact the Starship itself is a really problematic launch vehicle in many ways and has never delivered on any of its promises.

[Ashokk]

De-orbiting PS4 stage in PSLV-C56 Mission

August 05, 2023

PSLV-C56 vehicle successfully injected DS-SAR and 6 other satellites into their intended 536 km circular Low Earth Orbit (LEO) with a 5-degree inclination on July 30, 2023. The vehicle achieved the precise target orbit conditions in 20 minutes after lift-off using the Onboard Navigation, Guidance and Control system and completed its mission.

Left alone in a 536 km circular orbit, the PS4 stage would orbit the Earth for over 25 years. As the number of satellites in LEO is growing and the space around this orbit is of particular interest, the orbit of the spent PS4 stage was reduced to 300 km circular. In line with India's commitment to supporting worldwide space debris mitigation efforts, the Onboard Guidance Algorithm was modified to achieve this orbit-change manuevre. The Orbit Change Thrusters (low thrust engines) were fired twice for orbit change.

Furthermore, in line with standard launch practices, the PS4 Stage was passivated after the re-orbiting process, as no further active propulsion need was anticipated. This passivation involved venting of all pressurized compartments (Tanks/Gas bottles) to release any stored energy or potential hazardous substances. By mitigating the possibility of pressurized compartment failures, the chance of fragmentation of the spent stage in orbit is minimized, thereby further reducing the creation of space debris.

[Tanaji]

In fact the Starship itself is a really problematic launch vehicle in many ways and has never delivered on any of its promises.

Not a fan of Musk by any stretch, but why do you state it has not delivered? The thing hasn’t flown yet in the full configuration, but will. It is not particularly late either, at least not when compared to the stuff Boeing is doing.

Fully expect problems in getting such a large number of engines to fire together, but those would get solved I would expect?

OT I guess so perhaps in the other thread?

[sanman]

https://indianexpress.com/article/citie ... l-8875879/

In relief for Antrix Corp, US court reverses confirmation of $1.2 bn compensation for failed Devas satellite deal

Antrix Corp told the court at the time that Intelsat Service and Equipment LLC, a US company under bankruptcy proceedings in the Eastern District of Virginia, owed the ISRO commercial arm $146,457 and stated that this was the only asset of the company in the US. The US court for the western district of Washington allowed Devas to register its order in the Eastern District of Virginia.

The US appeals court has now ruled that Antrix Corp did not have sufficient local presence in the US for the courts to exercise jurisdiction on the foreign entity.

“Devas has failed to meet its burden under the first prong to show that Antrix purposefully availed itself of the privilege of conducting activities in the United States. Devas primarily relies on the Antrix and Indian Space Research Organization (“ISRO”) Chairman’s 2003 visit to Washington D.C. to meet with Forge Advisors and a series of 2009 meetings between ISRO officials and the Devas team,” the appeals court has stated in its August 1 order which is not meant to be a legal precedent in the US.

“Assuming that ISRO’s contacts with the United States may be attributed to Antrix, these meetings are still insufficient because they are not purposeful, but rather ‘random, isolated, or fortuitous’,” the US appeals court has stated.

“Principles of comity, diplomacy, and international law, including a panoply of mechanisms in the international arena, protect the interests that foreign states have in resisting the jurisdiction of United States courts,” one of the three judges on the bench said in a concurring opinion in the order.

[Mollick.R]

Lots of Info about Selection of Build Materiel for STARSHIP


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[Mollick.R]

Tata Play starts beaming from its GSAT-24 satellite, to increase capacity to 900 channels
PTI Last Updated: Aug 07, 2023, 04:36 PM IST

New Delhi: Direct-to-home (DTH) service provider Tata Play on Monday said it has started beaming of television channels from its dedicated GSAT-24 satellite which it has leased from Indian space agency ISRO. GSAT-24 was specifically launched for Tata Play (earlier knows as TataSky) in June last year, which will help increase its carrying capacity to 900 channels and cover the length and breadth of the country including far-flung places like Andaman Nicobar and Lakshsdweep islands.

After the launch, ISRO took time to place the satellite in the desired slot of 36,000 kilometre geosynchronous orbit. The satellite was first tested by Indian Space Research Organisation (ISRO) and handed over to Tata Play, which carried out its own tests.

Commenting over the development, MD & CEO Harit Nagpal said this will help Tata Play carry 900 channels, including the regional channels and Gyanwani channels, which would be launched by the government.

"This will help Tata Play to carry 900 channels from the present 600. It will also improve signal reception and channel capacity," he said, adding, "it will become largest satellite bandwidth provider among all DTH platforms."
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NSIL Chairman and Managing Director Radhakrishnan Durairaj said GSAT-24 has been the first demand-driven communication satellite mission undertaken by NSIL post space sector reforms.
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GSAT-24 is a 4-tonne 24-Ku band communication satellite built by ISRO only to cater to the requirement of Tata Play's DTH application needs.


READ FULL ARTICLE FROM HERE
https://economictimes.indiatimes.com/in ... content=23

[mody]

Why are we still using maraging steel for the S200 solid rocket boosters? Can composite rocket motors be developed for the same? We have now have composite rocket motors for the Agni-5. If the S200 can be made with composites, the weight would reduce and the obvious benefit would be a higher payload capacity.

Mody'ji, several posts might have explained it better. Here is my attempt:

The use case of a ballistic missile vs that of a launch rocket is different. For example, the "payload" of a ballistic missile absolutely has to come back down. Meanwhile the "payload" of a launch vehicle absolutely has to *not* come back down at all!

And that drives several aspects of the system. So a missile requires an efficient booster to throw the upper stages into a particular "window". Job done and damn the cost. For strategic missiles like Agni, the idea is that it gives Agony in mind of the opponents. Again cost is *not* the key here. More importantly, launches of such strategic missiles are fewer and far between (except when it is used, which hopefully is never). Again cost is not the key ...................................

There is an unhealthy obsession that bigger payload capacity makes your space program advanced. Bigger payload capacity helps, but that is not the sole criteria of being ahead in a space program. So comparisons of rockets just based on payload capacity is like juveniles comparing certain organs down under.

At the same time Indian space program has to evolve. But prior to that I think the Indian populace has to evolve. More on that later.

*PS: It took me 5-6 months to figure out how to contain a 40 N-s rocket motor and test it so that the next launch was perfect. Had to write some waivers and get additional insurance.

Thanks for the detailed reply.

[sanman]

[Ashokk]

Detailed explanation of the CY2 failure and the fixes implemented in CY3 given at the Prof S Pradeep Memorial Lecture at IISC by S Somanath (watch from 37:50)

[disha]

S. Somnath @IISc @Prof S Pradeep Memorial Lecture

[Ashokk]

Lots of information in the slides shown by S Somnath at the IISC lecture.
Some important dates -
The next orbit reductions will happen on 9th, 14th & 16th Aug, followed by lander and propulsion module separation on 17th. Then the lander will go through two de-orbit steps on 18th & 20th with the final touchdown on 23rd.

[disha]

< GareebScientist vlog >

Thanks Sanman'ji for the vlog from GareebScientist. Overall he does a good job, but he needs to start following BRF and can start taking more detailed and thorough analysis from BRF to improve is vlog.

I remember his line of questioning to ISRO chairman last time during the eve of C3 launch and there was visible irritation in ISRO chairman's voice on his interview with GareebScientist. I think the interview was covering the mundane and the chairman might have some pressing needs to attend to.

All the more for ISRO to have a PR panel that can firewall the ISRO scientist and also moderate any press meets.

[sanman]

< GareebScientist vlog >

Thanks Sanman'ji for the vlog from GareebScientist. Overall he does a good job, but he needs to start following BRF and can start taking more detailed and thorough analysis from BRF to improve is vlog.

I remember his line of questioning to ISRO chairman last time during the eve of C3 launch and there was visible irritation in ISRO chairman's voice on his interview with GareebScientist. I think the interview was covering the mundane and the chairman might have some pressing needs to attend to.

All the more for ISRO to have a PR panel that can firewall the ISRO scientist and also moderate any press meets.

Yes, I too scolded GS in the comments section, for his needless badgering of S Somnath.
GS was telling Somnath that lack of ISRO pics published online meant he couldn't use AI to generate pics from image repositories. Such a ridiculous argument.

But I'm still in favour of more independent niche journalists who can ask more interesting questions than legacy lame-stream media.
GS did ask a number of good technical questions regarding Chandrayaan and other missions, in contrast to legacy media who only cater to the broader uninformed masses with shallow fluff questions.

[NRao]

[sanman]

Here's another post mortem analysis from Scott Manley, after he watched S Somnath's explanation:

[csaurabh]

Lots of Info about Selection of Build Materiel for STARSHIP

I don't want to get into a debate of Stainless steel vs Carbon Fibre Composites. Both are good, depending on the application.

Rather my problem is with Elon Musk in general and Starship in Particular.
Elon Musk has made a list of extraordinary claims regarding Starship, such as

-Starship will be operational by 2022
-Starship can transport 100 people to Mars
-Starship can do orbital refueling
-Starship can do in-situ refueling on Mars
-Starship can transport cargoes to anywhere in the world
-Starship will make commercial airliners obsolete
-etc.

If you want a detailed breakdown and rebuttal of all this nonsense, you can watch this channnel
https://www.youtube.com/playlist?list=P ... 7IK1-1vZxB

Elon Musk just changed the logo of Twitter to an X. I think it's safe to say that he isn't a very stable personality and hasn't been for years.
That's why when he says anything about Starship, I can't separate fact from fiction.
It is just how Abhijith Iyer Mitra talks about Indian Defence Industry and Armed Forces. He talks so much nonsense, that I don't believe a word he says.

[SSridhar]

ISRO Conducts Drogue Parachute Deployment Tests for Gaganyaan Mission

August 11, 2023

Vikram Sarabhai Space Centre (VSSC)/ISRO, successfully conducted a series of Drogue Parachute Deployment Tests at the Rail Track Rocket Sled (RTRS) facility of the Terminal Ballistics Research Laboratory, Chandigarh, during August 8-10, 2023. The tests were conducted in collaboration with Aerial Delivery Research and Development Establishment (ADRDE)/DRDO.

The Gaganyaan mission entails the safe transportation of astronauts to space and back. A crucial component of this mission is the deployment of drogue parachutes, which play a pivotal role in stabilizing the crew module and reducing its velocity to a safe level during re-entry.

Drogue parachutes, packed within pyro-based devices known as mortars, are ingeniously designed to eject the parachutes into the air upon command. These conical ribbon-type parachutes, boasting a diameter of 5.8 meters, employ a single-stage reefing mechanism, ingeniously minimizing canopy area and mitigating opening shock, ensuring a smooth and controlled descent.

During the three comprehensive tests conducted at the RTRS facility, a range of real-world scenarios were simulated to rigorously evaluate the performance and reliability of the drogue parachutes. The first test simulated the maximum reefed load, marking a groundbreaking introduction of reefing in a mortar-deployed parachute within India. The second test emulated the maximum disreefed load, while the third test showcased the deployment of the drogue parachute under conditions mirroring the maximum angle of attack experienced by the Crew Module during its mission.

These successful RTRS tests serve as a critical qualification milestone for the drogue parachutes, confirming their readiness for integration into the upcoming Test Vehicle-D1 mission. Notably, earlier this year, the RTRS tests of Pilot and Apex cover separation parachutes were also conducted, further accentuating the progress of the Gaganyaan mission's parachute system development.

The intricate parachute sequence for the Gaganyaan crew module's deceleration system encompasses a total of 10 parachutes. The sequence commences with the deployment of two Apex cover separation parachutes, followed by the stabilization achieved through the deployment of two drogue parachutes. Upon release of the drogue parachutes, the mission transitions into the extraction phase, with three Pilot chutes individually extracting three main parachutes, a pivotal step in reducing the Crew Module's speed to safe levels for a secure landing.

[chetak]

Thanks Sanman'ji for the vlog from GareebScientist. Overall he does a good job, but he needs to start following BRF and can start taking more detailed and thorough analysis from BRF to improve is vlog.

I remember his line of questioning to ISRO chairman last time during the eve of C3 launch and there was visible irritation in ISRO chairman's voice on his interview with GareebScientist. I think the interview was covering the mundane and the chairman might have some pressing needs to attend to.

All the more for ISRO to have a PR panel that can firewall the ISRO scientist and also moderate any press meets.

Yes, I too scolded GS in the comments section, for his needless badgering of S Somnath.
GS was telling Somnath that lack of ISRO pics published online meant he couldn't use AI to generate pics from image repositories. Such a ridiculous argument.

But I'm still in favour of more independent niche journalists who can ask more interesting questions than legacy lame-stream media.
GS did ask a number of good technical questions regarding Chandrayaan and other missions, in contrast to legacy media who only cater to the broader uninformed masses with shallow fluff questions.

sanman ji,


there is neither a call for such type of niche journos in India and nor are there any. Only the liberal arts types manage to get into this media cesspool.

The odd ones, here and there, who have the expertise are the exceptions that prove the rule

The national geographic types don't bloom in this geography.

[sanman]

sanman ji,


there is neither a call for such type of niche journos in India and nor are there any. Only the liberal arts types manage to get into this media cesspool.

The odd ones, here and there, who have the expertise are the exceptions that prove the rule

The national geographic types don't bloom in this geography.

GareebScientist is a science channel covering Indian science stuff, from its own amateur perspective. They do a decent job, and just as the Youtube ecosystem has a variety of such channels for US space activities which ask good questions, we too should have our own such channels to repersent Indian space fandom. That being said, our people need to be respectful of Indian scientists and organizations, and not carry their amateurishness too far.

[chetak]

sanman ji,


there is neither a call for such type of niche journos in India and nor are there any. Only the liberal arts types manage to get into this media cesspool.

The odd ones, here and there, who have the expertise are the exceptions that prove the rule

The national geographic types don't bloom in this geography.

GareebScientist is a science channel covering Indian science stuff, from its own amateur perspective. They do a decent job, and just as the Youtube ecosystem has a variety of such channels for US space activities which ask good questions, we too should have our own such channels to repersent Indian space fandom. That being said, our people need to be respectful of Indian scientists and organizations, and not carry their amateurishness too far.

sanman ji,

do you remember what that bagla clown did during one of the press conferences some years ago....

he thought that he was running the space program and the engineers at ISRO and the ISRO chief were answerable only to him

this ignoramus should have been banned permanently, not only for his ill bred histrionics, but also for his sense of entitlement, but it looks like he is now back again.

when ISRO itself is so benignly forgiving, where is the question of respect from this illiterate gang of free loaders....

they need to deal with such characters with a well muddied, 12 sized bata boot, strategically applied, in an anatomically appropriate location that was defined by bagla's ample gluteus maximus, but they chose to let him back

I appreciate and subscribe to the points that you have made, but the real question is, do they.........

[sanman]

sanman ji,

do you remember what that bagla clown did during one of the press conferences some years ago....

he thought that he was running the space program and the engineers at ISRO and the ISRO chief were answerable only to him

It's true that our Indian unwashed masses have a tendency to behave on self-indulgent impulses.
Pallav Bagla was a little different, because he was a well-known space reporter who had already interviewed multiple ISRO chiefs.
He really should've known better, but cast his professionalism aside at the wrong moment.

this ignoramus should have been banned permanently, not only for his ill bred histrionics, but also for his sense of entitlement, but it looks like he is now back again.

when ISRO itself is so benignly forgiving, where is the question of respect from this illiterate gang of free loaders....

they need to deal with such characters with a well muddied, 12 sized bata boot, strategically applied, in an anatomically appropriate location that was defined by bagla's ample gluteus maximus, but they chose to let him back

I appreciate and subscribe to the points that you have made, but the real question is, do they.........

Maybe our amateur independent journalists need to undergo some vetting before they can be allowed to interview ISRO people directly.
However, independent niche journalism has shown that it can provide far more interesting coverage than older legacy media.
It should have a place, even if it requires refinement.

[Ashokk]

Agnikul Cosmos to soon launch India's first kerosene-oxygen-powered rocket

Indian firm Agnikul Cosmos is on its way to becoming the first in the country to privately design, develop and launch a liquid-fuelled rocket.

Liquid-fuelled rockets are much more complicated to design and build, when compared to solid-fuelled rockets.

Agnikul is targeting to launch their maiden rocket known as 'Agnibaan SOrTeD' (SubOrbital Technological Demonstrator) within a few weeks, the firm said.

Suborbital launches are meant to take the vehicle to the earth's upper atmosphere and not venture into space. Suborbital launches are the preferred method for startups to test and validate their maiden rocket, related sub-systems and thereby progress to more ambitious launch vehicle projects.

According to the firm, 'Agnibaan SOrTeD' is a single-stage launch vehicle driven by Agnikul’s patented Agnilet engine- an entirely 3D-printed, single-piece, 6kN semi-cryogenic engine.

Unlike traditional (solid-fuelled) sounding rockets that launch from guide rails, Agnibaan SOrTeD will lift off vertically and follow a predetermined trajectory while performing a precisely orchestrated set of manoeuvres during flight, they added.

In the presence of ISRO and IN-SPACe officials, members of the Agnikul team unveiled their launch vehicle at Agnikul's Mission Control Centre (AMCC), in the Indian Government-run spaceport, Satish Dhawan Space Centre.

Notably, Agnikul also has India's first private rocket launch pad, housed within the same campus.

“Delighted to see the progress Agnikul team has made so far. They have our best wishes to have a successful first flight and further activities”, said A. Rajarajan, Director of SDSC-SHAR, at the event where the vehicle was unveiled.

According to Srinath Ravichandran, co-founder and CEO of Agnikul, this upcoming suborbital launch is meant to validate Agnikul's proprietary autopilot, navigation, and guidance algorithms and the capability of their launchpad to undertake more complex missions.

Moin SPM, co-founder and COO of Agnikul, said, “Building a launch vehicle entails the integration of diverse systems, and coming together of various teams spanning different disciplines uniting towards a common goal. This vehicle standing on the launchpad is a testament of everyone’s hard work in the team.”

Agnikul was established in 2017 by Srinath Ravichandran, Moin SPM, and Prof. SR Chakravarthy, who hail from IIT Madras.

The firm’s primary objective is to democratise space exploration by making it both accessible and cost-effective.

The firm had been targeting a maiden launch by September 2022, but owing to the complexities and engineering sophistication involved in kerosene-liquid oxygen rockets, the firm has overshot their initial target by a year.

Notably, this will be the first kerosene-liquid oxygen (semi-cryogenic) rocket to be designed, developed and launched from India.

Meanwhile, the Indian space agency ISRO is also testing its own semi-cryogenic engine, but its engine is exponentially more powerful and sophisticated than that of the private firm.

ISRO's SCE-2000 is meant to significantly enhance the lifting power of India's LVM3 rocket.

[Amber G.]

foreign satellites launched by India:

United States: 231
United Kingdom: 86
Singapore: 20
Germany: 13*
Canada: 12
South Korea: 6
Israel: 5*
Italy: 5
Japan: 5
Luxembourg: 5
Algeria: 4
France: 4
Lithuania: 4
Switzerland: 4*
Netherlands: 3*
Austria: 3
Finland: 3
Indonesia: 3
Belgium: 2*
Denmark: 2
Spain: 2
Argentina: 1
Australia: 1
Brazil: 1
Chile: 1
Colombia: 1
Czech Republic: 1
China: 1
Kazakhstan: 1
Latvia: 1
Malaysia: 1
Mexico: 1*
Norway: 1
Slovakia: 1
Turkey: 1
UAE: 1

[srin]

Is there good info on NGLV and reusable launch vehicle (not the RLV-TD, but the full production RLV) ? I'm trying to read up but the most I can get is RLV-TD.

[Cyrano]

CY-2 loss seems due to poor software design and low quality testing & qualification (very regrettable, but shit happens) which went unchecked due to old school sarkari baabu PSU mindset (unforgivable). Successful moon landings happened decades ago, with a fraction of todays computing power and memory. It pains me to realise how close we got and lost it. I hope ISRO has learnt organisational and process lessons that go well beyond making CY-3 successful.

[Atmavik]

Is there good info on NGLV and reusable launch vehicle (not the RLV-TD, but the full production RLV) ? I'm trying to read up but the most I can get is RLV-TD.

Very early stages. So info is sparse. Listen to Somnath sir at 2 hrs 5 mins . The whole talk is interesting

https://www.youtube.com/live/k7wOlDJIbFc?feature=share

[sanman]

A guy I know made this animation awhile ago on India's space journey.
He made it back in 2007, just before the Chandrayaan-1 mission.

[sanman]

https://twitter.com/abhilashtomy/status ... 2876371143

[Tanaji]

What does it mean to have a rocket that is human rated?

I know there must be an escape mechanism for astronauts at the launch pad and low altitudes of flight, but what else? More 9s in resiliency?