Indian Space Programme Discussion

[abhik]

^^
That 2nd stage ISRO TSTO recovery looks like a pipe dream aka science project. Musk has basically given up trying to recover the Falcon 9 2nd stage because it involves a ~60% payload penalty. Even without burning any additional fuel to slow it down, the weight penalty because of the heat shield required to slow down the TSTO 2nd stage from orbital velocity will make it a financial non starter. Not to mention that without lifting surfaces as well as engines to slow and maneuver it , the actual landing location will not be precise. A non precision landing area for India means a sea landing which will destroy the 2nd stage. India does not have the vast open spaces of Russia where such landings are possible.

60% payload penalty for second stage reusability is not bad at all. If you have a 100% reusable rocket you can simply build a larger rocket with a lower payload fraction. I think this will be the next step for spacex. Even using the current falcon 9 with 60% reduced payload would be able to complete some of the past and future missions.

Regarding the landing accuracy, the dragon v2 is planned to 'propulsively' land (using parachutes only as a backup). So don't think that would be a problem.

[symontk]

Moreover ISRO need only recover the 2nd stage engines and not the entire stage with fuel tanks which makes it a possible venture

My dream..Variants to the RLV could be a. satellite launch vehicle b. space personel trainer (solo quick round trips over equator) c. airforce version for laddoos

[sukhish]

the space X booster which landed safely on May 6 suffered extensive damages, it cannot be re-used for another launch.
the cost saving theory is still up in the air. the only thing they have demonstrated is landing. even if they re-use the first stage, it will be after
extensive refurbishment, which will be pretty expensive as well.

[TSJones]

^^^^not necessarily.....the first two successful landings were low earth orbit missions and the last I heard they will be reused,

the third successful landing was a higher orbit, higher speed mission. the launch core was damaged upon reentry due to the increased speed.

so all of this is still in its infancy with more details to be worked out.

[sukhish]

even the first two booster are yet to be used. I suspect that the cost to refurbish them will be much higher.

[VenkataS]

It does not matter if the technology was handed to SpaceX on a platter. What is stopping ISRO from doing the same thing and cultivating capable private Indian players in the space market.

What ISRO is doing is cool and what SpaceX is doing is cool as well. They are treading new territory with respect to landing their boosters back on earth. We should count on them being in the game over the long haul. Even if the first few/several boosters that they land are not reusable they are gaining valuable insight during this process.

SpaceX might turn out to be a credible competitor to ISRO in terms of lowest cost/per kg to orbit. ISRO should be prepared for this and plan their projects accordingly.

[shiv]

If one SpaceX comes into existence - expect a few more - if it is really easy and achievable without massive assistance from a larger organization. Unlikely to be ISRO. Going by history the real competition or Boeing came from Airbus (Not to mention that Boeing chewed up American competitors)

Other things like niche role microsatellites launched by aircraft mounted missiles may eat into even SpaceX's future. Much depends on who wants what space service and how much space launches are subsidized by national governments as a "strategic" asset.

[TSJones]

it is certainly not easy to land a 1st stage core on a barge at sea or fly it back to land near the launch site.

if a such a criteria is considered easy then you're criteria needs adjusting.

what I am hoping for is that India will build a space plane (and a space capsule). I am certain that India can do this and show the Chinese a thing or two.

[disha]

^^ Rocket science is not easy that is why the cliche prevails "it is rocket science"., otherwise even Brazilians & North Koreans & Bakistanis will be flying rockets.

Coming to India building a space plane or space capsule., it will build one when it perceives it needs one and not to do this or that to show Chinese a thing or two. Anyway, India has not just shown a chinese a thing or two but also to Americans and the ESA and the Russians a thing or two. Take the case of Chandrayan and Mangalyan. Excellent science at shoe string budget and what's more - first ever country to reach Mangal on its first ever try. Speaks volumes about the engineering capability of ISRO.

So ISRO does not have to prove anything to anybody. ISRO has to just focus on its mandate., that is bring space sciences to bear on improving & securing the life of ordinary Indians. Whether it is by orbiting INSATs (my uncle still calls everything that is in GEO as INSAT!) or by orbiting Astrosat.

[disha]

It does not matter if the technology was handed to SpaceX on a platter. What is stopping ISRO from doing the same thing and cultivating capable private Indian players in the space market.

Are you sure that ISRO is not cultivating capable private Indian players? If you have proof to your above statement, please let us know.

Coming to SpaceX., it did not get anything on platter., it was breastfed by NASA - check out Elon Musk's statement. After the infant becomes toddler., it is always nice to say - "look that baby is now standing on her own two legs".

Now coming to "it does not matter if technology was handed to spacex on platter"., what you miss that the technology has to be developed first for it to be handed over to a private player. No private player is going to take the risk of flying a shuttle or launching a retro-rocket equipped rocket unless it is assured of returns on its investments including failures. So that risk is taken up first by public agencies (NASA/ISRO) and then passed on based on COTS benefits.

What ISRO is doing is cool and what SpaceX is doing is cool as well. They are treading new territory with respect to landing their boosters back on earth. We should count on them being in the game over the long haul. Even if the first few/several boosters that they land are not reusable they are gaining valuable insight during this process.

US has lots of money., it is almost 10x times the Indian economy. Its USAF can afford to fly space shuttles like X-37B while its COTS program can encourage spacex to try alternatives like retro-boosters (which can also be used for say landing on asteroids or mars or titan or moon etc).

For ISRO on shoe string budgets and Jean Druze class detractors., it is always going to use its budget sparingly., where it can make calculated bets for assured returns. Hence the comparison between NASA/SpaceX/US and ISRO/India is invalid and IMHO unnecessary.

SpaceX might turn out to be a credible competitor to ISRO in terms of lowest cost/per kg to orbit. ISRO should be prepared for this and plan their projects accordingly.

The problem with rocket launches is, even though there will be initial spare capacity - the demand eventually far outstrips the supply. For example Ariane is fully booked till 2016/2017. To get on Atlas launch, Mexico is grovelling. Even ISRO's launch schedule is full and they are upto their nose just trying to meet the existing demand.

Point is commercialization of space is gathering even fervent pace., and that means there will be no dearth of competitor at the same time there will be no dearth of demand (for example, US small sats may have to deal with a locked in market within US!) and Indians may find it cost prohibitive to hitch a launch on say Atlas.

Hence instead of focusing on what SpaceX is doing (or not doing)., the focus should be on basics - that is cheaper, better, safer and faster.

ISRO's RLV-TSTO must be viewed in that context.

[disha]

60% payload penalty for second stage reusability is not bad at all. If you have a 100% reusable rocket you can simply build a larger rocket with a lower payload fraction. I think this will be the next step for spacex. Even using the current falcon 9 with 60% reduced payload would be able to complete some of the past and future missions.

Problem with that equation is that to achieve a particular payload, one starts to add more fuel to compensate for the penalty. More fuel means more weight. More weight means more design complexity. More design complexity means more variables (or points of failure). More variables means more chances of failure. More chances of failure means more costly. More costly means the stage reusability is dud.

You see the function quickly spirals out of control on cost estimates and return on investments.

So to say one system will beat another system is premature. In fact, one may end up living with multiple systems - all viable. For example one has a Maruti as well as a SUV and a Bajaj scooter. Depending on the need, the vehicle will be brought in use.

---

What is the future of space? Is it sending some well heeled tourists into space? Or launching EO and Comm sats? Or sending out probes to distant planets? This is the ultimate question we have to answer.

Imagine a world where a robotic space probe mines the moon or the asteroids for helium or metals? Yes, that is the primary goal for space exploration as it currently stands - so that resources like iron-nickel-tungsten-gold can be mined or helium can be obtained for energy. Reducing cost to reach space to get the resources hence is the key. That is if you have a rocket that can bring @1Kg of gold in < 40k USD (or 1000 Kg of gold < 40,000 k USD) - you have a winner. That is the true cost factor IMHO we should be tracking.

[disha]

This is what ISRO must target in next 20 years:

On Asteroids:

1. Ability to Identify and land on a M or S-Type asteroid
2. Mine an S/M-Type asteroid for metals (nickel/platinum/gold/...)
3. Bring back the raw material (or mined metals)

More importantly from Moon:

1. Mine water and 3He
2. Consolidate and bring 3He to earth as a fusion fuel.
3. Establish a moon colony to mine 3He for uninterrupted and uninterruptible source of energy for earth.

https://www.technologyreview.com/s/4085 ... -the-moon/
https://www.technologyreview.com/s/4083 ... ions-soar/

[symontk]

Whether it is by orbiting INSATs (my uncle still calls everything that is in GEO as INSAT!) or by orbiting Astrosat.

All ISRO satellites are derived from same INSAT satellite bus, its known for variants such as I-1K, I-2K etc. The other series they are now developing are the IMS ones. So he may be correct in calling them all INSATs

FWIW

[TSJones]

This is what ISRO must target in next 20 years:

On Asteroids:

1. Ability to Identify and land on a M or S-Type asteroid
2. Mine an S/M-Type asteroid for metals (nickel/platinum/gold/...)
3. Bring back the raw material (or mined metals)

More importantly from Moon:

1. Mine water and 3He
2. Consolidate and bring 3He to earth as a fusion fuel.
3. Establish a moon colony to mine 3He for uninterrupted and uninterruptible source of energy for earth.

https://www.technologyreview.com/s/4085 ... -the-moon/
https://www.technologyreview.com/s/4083 ... ions-soar/

ambitious and laudable goals. but on a "shoe string budget"?

[kit]

This is what ISRO must target in next 20 years:

On Asteroids:

1. Ability to Identify and land on a M or S-Type asteroid
2. Mine an S/M-Type asteroid for metals (nickel/platinum/gold/...)
3. Bring back the raw material (or mined metals)

More importantly from Moon:

1. Mine water and 3He
2. Consolidate and bring 3He to earth as a fusion fuel.
3. Establish a moon colony to mine 3He for uninterrupted and uninterruptible source of energy for earth.

https://www.technologyreview.com/s/4085 ... -the-moon/
https://www.technologyreview.com/s/4083 ... ions-soar/

ambitious and laudable goals. but on a "shoe string budget"?

compared to the US

but no worries .. a million dollars will buy you much (much) more in India !! one billion in India would be worth more than 10 ( maybe a 100) in the US

[Gagan]

Specific asteroids which are rich in specific minerals will need to be found. Say an asteroid relatively rich in titanium ore.
They will need a satellite with a mass spectrometer etc to locate and track.

Then there will have to be landers, which will mine, and then send back to orbit earth. Then de-orbit and bring these ores back to earth.

All feasible, but needs 1. MASSIVE launch capability, 2. Coordination of multiple satellites - needs global cooperation. 3. Expense. 4. High failure rates

[RoyG]

We haven't seven scratched the earths crust yet. I'm sure we'll be fine mining on the ground.

[jamwal]

https://imgur.com/a/D9t65

RLV-TD being worked on at VSSC. All images by Pallav Bagla (30 March 2016)

[arshyam]

http://timesofindia.indiatimes.com/home ... 276174.cms

The RLV-TD is unlikely to be recovered from sea during this experiment as it is expected that the vehicle will disintegrate on impact with water since it is not designed to float. The purpose of the experiment is not to see it float but to glide and navigate from a velocity five times higher than the speed of sound onto a designated virtual runway in the Bay of Bengal some 500 km from the coast.
Very similar in its looks to the American space shuttle, the RLV-TD being experimented is a scale model which is almost 6 times smaller than the final version.
K Sivan, director of the Vikram Sarabhai Space Centre, Thiruvananthapuram, says, "These are just the first baby steps towards the big Hanuman leap."

This article deserves to be posted in full.

Isro's big leap, embarks on launching Indian space shuttle - PTI via ToI | May 15, 2016, 09.50 AM IST

THIRUVANANTHAPURAM: For the very first time in its history, the Indian Space Research Organisation (Isro) is actually growing wings as it embarks this month on a never before space flight that would make history.

The Indian space agency is all set to undertake the maiden launch of its very own indigenously version of a 'space shuttle', a fully made-in-India effort.

Today, a sleek winged body almost the weight and size of a sports utility vehicle (SUV) is being given final touches at Sriharikota awaiting the final countdown.

Yes, the big powers abandoned the idea of a winged reusable launch vehicle but India's frugal engineers believe the solution to reducing cost of launching satellites into orbit is to recycle the rocket or make it reusable. Scientists at Isro believe that they could reduce the cost of launching stuff into space by as much as 10 times if reusable technology succeeds, bringing it down to $2,000 per kg.

Very soon and if all goes well possibly before the monsoon sets in, India's space port at Sriharikota on the coast of the Bay of Bengal in Andhra Pradesh will witness the launch of the indigenously made Reusable Launch Vehicle - Technology Demonstrator (RLV-TD). This will be the first time Isro will launch a space craft, which actually has delta wings and after launch it will be glided back onto a virtual runway in the Bay of Bengal.

The RLV-TD is unlikely to be recovered from sea during this experiment as it is expected that the vehicle will disintegrate on impact with water since it is not designed to float. The purpose of the experiment is not to see it float but to glide and navigate from a velocity five times higher than the speed of sound onto a designated virtual runway in the Bay of Bengal some 500 km from the coast.

Very similar in its looks to the American space shuttle, the RLV-TD being experimented is a scale model which is almost 6 times smaller than the final version.

K Sivan, director of the Vikram Sarabhai Space Centre, Thiruvananthapuram, says, "These are just the first baby steps towards the big Hanuman leap."

The final version will take at least 10-15 years to get ready since designing a human rated reusable rocket is no kid stuff.

The only countries that have attempted operational flights of a space shuttle are America, which flew its space shuttle 135 times and then retired it in 2011 and since then it lost its capacity to send astronauts in space on American made rockets. The Russians made only a single space shuttle and called it Buran it flew into space just once in 1989. After that the French and Japanese have made some experimental flights and from available literature it seems the Chinese have never attempted a space shuttle.

India embarked on making its own version of the space shuttle by thinking about it more than 15 years ago, but work in earnest it seems started only five years ago when a dedicated team of engineers and scientists plunged into making RLV-TD a reality. The 6.5-m-long 'aeroplane'-like spacecraft will weigh 1.75 tons and will be hoisted into the atmosphere on a special rocket booster.

The special booster or the first stage is powered using a solid fuel and it will hoist the RLV-TD experiment to about 70 km into the atmosphere from where the descent will begin. During the descent phase, which is essentially a glider like event, small thrusters will help the vehicle to be navigated on to the exact spot where it is supposed to land.

Ships, satellites and radars will monitor its descent. The current experimental version has no undercarriage so it cannot be brought back onto land and India lacks a runway that is longer than 5 km in length to accommodate such a landing. {So how are we planning to test the LEX phase? Is a landing strip being built somewhere?}

Some private billionaires with very active support from Nasa have been trying to master vertical lift-off and vertical landing as part of trying to recycle rocket engines.

SpaceX is a company owned by South Africa-born billionaire Elon Musk which became big through the Internet economy and has been able to land its Falcon-9 rocket onto a sea-based platform.

On the same lines the company Blue Origin owned by Jeff Bezos landed its New Shepard rocket on land in Texas. Bezos, another billionaire, made it big by building the Amazon online trading platform.

In fact Nasa chief General Charles Bolden, when he was in New Delhi recently, said the competition has shifted to a fight among billionaires to reduce the cost of launching satellites into space.

The making of the Indian space shuttle or RLV-TD has taken 5 years and the government has invested Rs 95 crore in the project. This flight will test the capability of the vehicle to survive a re-entry at speeds higher than that of sound so it is called a hyper sonic experiment (HEX).

Later, in the next few flights the RLV will be subjected to a landing experiment and another return flight experiment. Once these are successful, Isro will then decide on what should be the final configuration of the Reusable Launch Vehicle.

One key technology the scientists at VSSC had to develop was to make materials that can withstand the very very high temperatures that the exterior of the vehicle is faced with as it comes back into the dense atmosphere after its journey through near vacuum in space.

The friction from the air turns the exterior like a red-hot iron plate. To be able to withstand these 5000-7000 degrees Celsius temperature the scientists have developed very lightweight heat resistant silica tiles that are plastered on the underbelly of the so-called Indian space plane.

The nose cone takes the brunt of the high temperatures and is made up of a special carbon-carbon composite that can withstand high temperature. These special materials are necessary to protect the insides of the vehicle where the temperature should never go higher than 50 degrees Celsius.

In fact, it is these heat resistant tiles and thermal coating that failed on the American Space Shuttle, Columbia that resulted in the death of Indian born American astronaut Kalpana Chawla's in 2003. Consequently, Isro has laid a lot of emphasis on the thermal management of the RLV.

After the successful deployment of the swadeshi Global Positioning System through NAVIC or Navigation with Indian Constellation, Isro is again reaching for the stars.

Technology development is tough and space fairing is certainly not for the faint hearted and the 600 scientists and engineers who have toiled hard in making the RLV-TD a reality will be watching with baited breath if their baby succeeds.

Shyam Mohan, the project director from VSSC for this landmark experiment, says his team has spent sleepless nights in perfecting this new rocket but adds that space technologies are inherently risky.

So will Isro succeed where other super powers have failed, Indians certainly hope for the best, as success has become a habit at Isro.

May be sooner than later the RLV should be named the 'Kalamyaan' after India's legendary former President APJ Abdul Kalam, an aeronautics engineer par excellence who made top class rockets and dreamt big of India being propelled to become a developed country.

For Isro, no dream is too big as it carefully forges ahead to have a fully 'swadeshi space shuttle'.

[rajithn]

Look at what Zaptec intends to do: http://www.zaptec.com/zapspace/#zapspace-1

[disha]

http://timesofindia.indiatimes.com/home ... 276174.cms

Ships, satellites and radars will monitor its descent. The current experimental version has no undercarriage so it cannot be brought back onto land and India lacks a runway that is longer than 5 km in length to accommodate such a landing. {So how are we planning to test the LEX phase? Is a landing strip being built somewhere?}

From Mandvi to Barmer to Jodhpur to Palanpur to Mandvi., you have some 50,000 sq. km. of barren flat lands with good road, air and ship connectivity. I am sure, 25 sq km of landing space range can be found. Land the RLVs there., put them on a barge from Mandvi and bring them back to SHAR. A secondary option is 250 sq. km between SriKalahasti and the sand bar of Chinnathota (just north of SHAR). North of SHAR itself has some 100 sq.km of land which can be used to make an air strip (a 3rd emergency landing if necessary).

Basically there are plenty of options.

[disha]

https://imgur.com/a/D9t65

RLV-TD being worked on at VSSC. All images by Pallav Bagla (30 March 2016)

Next they should borrow the landing gear from NLCA, retrofit on to the RLV. Add an engine for thrust maneuvering and skip the LEX and go straight to REX. And also scale up in the process., next one should be straight away 6x bigger and also launch on a heavier booster. Note that the HS9 is a 9T booster (basically a souped up SLV-3 core!)., so a fully scaled REX with landing gear from NLCA can be launched with S200 (LVM3's booster!) to a high orbit and carrying a payload.

Current RLV-TD weighs 1.5 Tonnes and a 6x scale up will mean a mass of 3-4.5 Tonnes (assume it at 4500 kg)*., and launching with S200 means a circular 185/185 Km can be achieved.

I think this itself can be an intermediate 'small cargo plane'. The rocket booster itself can than have wing attachments and parachutes/inflatable bags to glide it back to a launch point.

*A 6x scale up increases volume disproportionately than mass. That is a 6x scale up will NOT translate into a 6x mass increase., a 3x mass increase is taken as a baseline. Though a 2x mass increase should the norm., leaving a payload of 1 - 1.5 tonnes.

Point is., this project must be scaled up fast.

[SriKumar]

In the TOI article posted by arshyam, it says that it will land 500 km off the shore in Bay of Bengal. IS this right?

Why so far away from the shore is a mystery. If they have enough accuracy to land on a runway i.e. an accuracy of maybe +/- 50 m (and if the only reason for not landing on land on land is the lack of an actual runway) they could have landed it within a km or two (or 10) off the coast where the sea is shallower, and proximity to land makes recovery much much easier. Putting it so far away from the coast does not compute (other than safety reasons i.e. accuracy of an automated landing is not good enough to put it in an area of actual runway dimensions).

[symontk]

They had plans for S-1000 sized Reusable landing solid booster with cryo on top for launching satellites. Not sure if they are pursuing it now

[srin]

In the TOI article posted by arshyam, it says that it will land 500 km off the shore in Bay of Bengal. IS this right?

Why so far away from the shore is a mystery. If they have enough accuracy to land on a runway i.e. an accuracy of maybe +/- 50 m (and if the only reason for not landing on land on land is the lack of an actual runway) they could have landed it within a km or two (or 10) off the coast where the sea is shallower, and proximity to land makes recovery much much easier. Putting it so far away from the coast does not compute (other than safety reasons i.e. accuracy of an automated landing is not good enough to put it in an area of actual runway dimensions).

Even better would have been something like Chilka lake (64km max length and max depth of 4.2m), but I guess they feel the cost of recovery outweighs the benefits significantly, esp since the telemetry would provide all the data they care about.

[srin]

From Mandvi to Barmer to Jodhpur to Palanpur to Mandvi., you have some 50,000 sq. km. of barren flat lands with good road, air and ship connectivity. I am sure, 25 sq km of landing space range can be found. Land the RLVs there., put them on a barge from Mandvi and bring them back to SHAR. A secondary option is 250 sq. km between SriKalahasti and the sand bar of Chinnathota (just north of SHAR). North of SHAR itself has some 100 sq.km of land which can be used to make an air strip (a 3rd emergency landing if necessary).

Basically there are plenty of options.

It isn't just one runway - eventually (probably not right now) you'd need to have one additional as an alternate. Space shuttle launches / reentries depended upon availability of alternate airstrip. I wonder if it would be very hard to equip it to land on water like an amphibian instead of building a long runway airstrip ...

[member_28108]

The cost for recovery of most of these is extremely high even if it is within the littoral region or away from it. That is why most sunken parts are not recovered.The price is not just worth it and will require massive mobilization of the navy etc etc. The logistics of that is not so simple.All the data they need will be got be telemetry and they may also be having a chase plane for optical tracking.. They already have splashdown data from the SRE experiments. The LEX experiment will be to study landing characteristics. The present study is to see how to do high speed(approx Mach 5) bleeding maneuvers and reentry as well as studying the launch data through the lower dense atmosphere etc.

[SriKumar]

The cost for recovery of most of these is extremely high even if it is within the littoral region or away from it.

How much is it, roughly? When you say 'extremely high', could you give some idea?

[kit]

just curious .. why not have the re entry vehicle have some inflatable ballasts that will automatically trigger off at splash down ?.. and the radio transponders aboard can cue the location for pick up ? .. is that too expensive ?

[Singha]

Tens of crores most likely. Big money will only come once they progress further into operationalise it.

More pix released
http://www.ndtv.com/india-news/exclusiv ... ?site=full

[member_28108]

Imagine destroyers, coast guard, marines etc tracking a large swath of Indian ocean. I do not know the figures but was told that it is indeed very costly affair. Supposed to be a huge amount spent every time a capsule (Apollo etc ) splashed down apart from a lot of coordination between various agencies and navy.
The inflatable ballast was already studied with SRE2 and CARE which was recovered. The goal is not for a splashdown which they must have already got enough data with SRE2 and CARE . Also this is not for a "splashdown" but is being made to land on a "virtual runway". That is the goal. probably will disintegrate when it tries to "land on water" and not like the Hudson river landing which actually only has happened twice and the buoyancy may not be designed for that. One must remember that this is probably a 1/10th model

[member_28108]

The Orion capsule for perspective carries 680 Kgs of inflatable airbags. All that adds to weight wrt the capsule itself.

[Varoon Shekhar]

Considering that the launch is taking place on Monday( as per news reports), there is nothing about it on the ISRO website! Usually, with any missions, they preview them one week earlier.

Maybe they don't want to hype this test, considering it's the first such mission of its kind, and the complexity of it. With the real chance of a first launch snag? Good approach, if that's what they are thinking.

[Varoon Shekhar]

June 10/2016 launch date:

What? How authentic is this? Remember that there was supposed to be an ISRO mission, where 21 satellites were going to be launched? Is that now cancelled or postponed, and instead they are launching Cartosat and SRE-2? Well, one very good thing, is that SRE-2 is finally going to be launched, if this info is accurate! It had been pushed to the background for many years.

from spaceflights.news:

ISRO is planning to improve their constellation of cartography satellites. Cartosat-2C is observation satellite designed by ISRO and equipped in panchromatic camera for scene-specific black and white pictures suitable for cartography. It is fourth of Cartosat-2 constellation since first launch in 2007. Cartosat-2C will operate on altitude of 630 km for five years.
With Cartosat-2C ISRO is going to launch in this mission following satellites: NEMO-AM (Nanosatellite for Earth Monitoring and Observation – Aerosol Monitoring)-satellite developed in cooperation between ISRO and UTIAS (University of Toronto, Institute for Aerospace Studies) for measuring with spectrometer level of aerosol content in the atmosphere, IMS-1B observation nanosatellite developed by ISRO, and SRE-2 (Space Capsule Recovery Experiment) capsule for conducting scientific experiments in outer space.

[SriKumar]

Imagine destroyers, coast guard, marines etc tracking a large swath of Indian ocean. I do not know the figures but was told that it is indeed very costly affair. Supposed to be a huge amount spent every time a capsule (Apollo etc ) splashed down apart from a lot of coordination between various agencies and navy.

Well, I doubt one needs to scan a large swath of the Indian ocean. As you said, they are going to land this on a virtual runway. In which, case we are talking about a swath that is roughly about 0.5 km by 5 km or thereabouts. And if indeed, there will be optical tracking as you mentioned in your earlier post, then the landing location will be known pretty much exactly. This was done when Nirbhay missile was tested, by the way. A Su 30 tracked it.

[member_28108]

You have to realize that while the landing zone may be few Kms long the actual area under observation will be much larger in any experimental flight.Even with the Apollo and Soyuz capsule touch downs the area monitored were huge. In fact in many splat downs of Soyuz the actual landing area was sometimes very far away. Also remember this is the first time we are going to be doing it so everything may not be as predicted but we hope it does. Anyway in this test they are not bothering to recover it.That will be the mandate of LEX.
Also we cannot equate it to Nirbhay tracking this is hypersonic and our aircraft cannot scramble and follow it so easily.Chasing it may not be possible like Nirbhay but may be tracked from a distanceor a chain of tracking planes.

[SriKumar]

You have to realize that while the landing zone may be few Kms long the actual area under observation will be much larger in any experimental flight.Even with the Apollo and Soyuz capsule touch downs the area monitored were huge. In fact in many splat downs of Soyuz the actual landing area was sometimes very far away.

I agree that landing area could be larger, but certainly not the large swathes that you refer to. Apollo and Soyuz are old programs and the comparison is hardly warranted. They did not have the benefit of modern navigation electronics. Plus those crafts were not truly steerable i.e. no wings and aerodynamics shape. This craft is more shuttle-like than Apollo capsule-like. And it is supposed to autonomously steer itself to a 'designated virtual runway', so it has to know its own position with an accuracy of meters if it is to land on a designated runway. I assume it will be using GPS of some sort GAGAN? (though this is not mentioned anywhere). In this case, telemetry from the craft alone will allow ISRO to determine its landing location fairly closely.

Also we cannot equate it to Nirbhay tracking this is hypersonic and our aircraft cannot scramble and follow it so easily.Chasing it may not be possible like Nirbhay but may be tracked from a distanceor a chain of tracking planes.

Well, it will be hypersonic during re-entry and not after that due to the deceleration from aerodynamic forces. It is going to carry out maneuvers to bleed off energy and slow down significantly, to a speed that permits a landing. As it comes to its virtual runway (which should be a pre-determined area in the Bay of Bengal) it will slow down, permitting visual tracking. In any case, whether it is one plane or a multitude of planes, its splashdown position would be known.

I doubt that tracking cost is the reason it is being dropped 500 km offshore into Bay of Bengal. But I am not sure what it is, perhaps safety is one possibility. I do think there is a benefit to recovering the object, even if in pieces. For example, heat damage to thermal tiles can be determine (telemetry alone is not enough). Any other physical damage to the craft (cracks etc) would also be useful information for the next test.

[member_28108]

There are sensors to track heat damage etc. I did not say that tracking is the reason to drop it 500 Kms away. I said it makes no difference whether it is within the Littoral zone or further away. The last I heard the Soyuz program is very much functional !! For an initial experiment where the focus is more on the aerodynamics of the body landing and recovery may not be important till the first part is validated. Also these experiments are being done on a shoe string budget (relatively) so just like the subatmospheric test of GSLV this is a toddlers step in a way. As far as thermal damage etc - the integrity of the tiles etc have been validated already. The monitoring of tile integrity etc would be done by sensors.Anyway a whole team of engineers have determined that this part is what is realistically and economically feasible.

[SriKumar]

Well, Soyuz is functional but what about the accuracy.... I think you brought it up as an example of lack of landing accuracy. This craft is different for reasons mentioned above (different form of craft, navigation electronics). About heat sensors, they will track only temperature and nothing more. If you recall, in the very first shuttle flight, it lost some tiles during lift-off (due to vibrations at lift-off). This is a different craft from SRE and things like tiles can behave differently- different aerodynamic forces etc (in fact validating aerodynamic forces is one of the aims of this test).

I understand the part about economic realities and baby steps etc. That is always a limiting factor. If some additional information is made available after the test, may be it will answer some questions.

[member_28108]

Well, Soyuz is functional but what about the accuracy.... I think you brought it up as an example of lack of landing accuracy. This craft is different for reasons mentioned above (different form of craft, navigation electronics). About heat sensors, they will track only temperature and nothing more. If you recall, in the very first shuttle flight, it lost some tiles during lift-off (due to vibrations at lift-off). This is a different craft from SRE and things can behave differently.

In fact the tile damage was etected when the heat sensors detected a rise.The subsequent recordings just confirmed the cause whioch was already predicted byt the sensor data in the ill fated craft.

As is where is now we know nothing about controlled reentry - remember this is a first of a kind experiment for us so we kust have to expect the unexpected however much our simulations may be . That is why the extra caution and breaking up each portion into parts.