ISRO General News and Updates

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http://indico.vecc.gov.in/indico/contributionDisplay.py?contribId=72&sessionId=13&confId=44
Design and analysis of Methane pump

Content: In rocket propulsion weight has a vital role on efficiency and cost of the program. Since fuel, oxidizer and delivery system contribute a major share of the total weight; so it is desirable to design an efficient fuel delivery system as well as choice of fuel. Methane has been chosen as the next generation cryogenic fluid for its certain advantages over liquid hydrogen and kerosene. Pump-fed system is a well-established preferable fuel delivery system as compared to pressure-fed system. Pump-fed system is commonly known as turbo-pump system; as it consists of turbine and pump. Pump gives the necessary pressure rise to the fuel and oxidizer while turbine acts as the prime-mover. The present work is limited to design and analysis of the pump part alone. Although pump-fed system has been successfully designed for various propellants, but the research is limited and new for methane as working fluid. Centrifugal pump is preferable to other kind of pumps because of its compact size and a wider throttling range. However, an inducer is necessary before impeller to meet the NPSH requirement of the pump. The focus of the work is to determine the throttling range of the system for operating.
Summary: Methane is a soft cryogen and hugely available in other planets. For inter-planetary motion if methane is used as fuel, it is possible to refill fuel at the destination point. Thus additional fuel storage for returning of the vehicle can be avoided. Further Methane is eco-friendly fuel and have acceptable specific impulse. A turbo-pump assembly is a pump powered by a turbine used to raise the fuel and oxidizer pressure. This eliminates necessity of high tank pressure and thereby thickness of tank chamber. Study is carried out to analyse of the fluid flow through the pump.

Next gen cryogen based on Methane?
Anyway, thanks NSF.
 

Chinmoy

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Jun 08, 2017
The first orbit raising operation of GSAT-19 Satellite has been successfully carried out by LAM Engine firing for 116 sec from 14:03 hr IST on June 06, 2017.
Orbit Determination results from this LAM firing are:

Apogee X perigee height was changed to 35938 km X 172.77 km.
Inclination is 21.56 deg.
Orbital period is 10 hr 33 min.

Jun 08, 2017
The second orbit raising operation of GSAT-19 Satellite has been successfully carried out by LAM Engine firing for 5538 sec from 15:44 hr IST on June 07, 2017.
Orbit Determination results from this LAM firing are:

Apogee X perigee height was changed to 35840 km X 10287 km.
Inclination is 7.02 deg.
Orbital period is 13 hr 58 min.
I thought the perigee of GSAT-19 would be 172 km which they achieved at First orbit rising. Then why change it to 10287? Could it be because of the orbital period?
 

Indx TechStyle

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I thought the perigee of GSAT-19 would be 172 km which they achieved at First orbit rising. Then why change it to 10287? Could it be because of the orbital period?
May be or CUS may have delivered it to a greater height first.
 

Chinmoy

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May be or CUS may have delivered it to a greater height first.
Unlikely........... The apogee and perigee doesn't match with what mission specification brochure had been published prior to this. I have take liberty of collecting it from your post.
IMG_20170604_110657_405.jpg

But anyway, whatever be the reason, I am waiting for the beast to work on and deliver :)
 

G10

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Unlikely........... The apogee and perigee doesn't match with what mission specification brochure had been published prior to this. I have take liberty of collecting it from your post.
View attachment 16589
But anyway, whatever be the reason, I am waiting for the beast to work on and deliver :)
Launcher parameters and satellite parameters are different. GTO is not so elliptical. Its more circular. Perigee will increase more with apogee near about same.
 
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Chinmoy

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Launcher parameters and satellite parameters are different. GTO is not so elliptical. Its more circular. Perigee will increase more with apogee near about same.
If you would have a look at the image, it was said that the Apogee and Perigee of the GTO orbit to be of 35975 and 170 km respectively. Now orbit would be for satellite only, not the launcher.
 

G10

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My bad GTO and GO is different. Launcher gives elliptical GTO. Satellite is then transferred to circular geo synchronous ie. GO.
 

shiphone

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on our forum , it was observed and discussed few days ago as well...

this time, it seems that CE-20 was a little bit underperformed
the seperation orbit was 156 x 34913 km x 21.55° ,about 10m/s Dv short, 1000km lower apogee ...then here came the first Satellite orbit raising which explained and confirmed it

but it's fine, anyway, it's the first flight...such glitch won't reduce the service life of satellite

as I said two about years ago, a well designed and performed CE-20 was the realistic key factor for LVM-3/GSLV-mk3 in short term ...this first show approved it has achieved the goal...
ISRO seems satisfied with it and the whole rocket...they are confident to plan a 0.5 ton payload increase in the next mission in 2018 via parameter adjustment of L-110 and C-25 stages .
----------
the live broadcast indicated the CE20 real performance deviated a little bit from the desired curve
120147ytn9qffn0wvww8fo.jpg
 
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AnantS

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on our forum , it was observed and discussed few days ago as well...

this time, it seems that CE-20 was a little bit underperformed
the seperation orbit was 156 x 34913 km x 21.55° ,about 10m/s Dv short, 1000km lower apogee ...then here came the first Satellite orbit raising which explained and confirmed it

but it's fine, anyway, it's the first flight...such glitch won't reduce the service life of satellite

as I said two about years ago, a well designed and performed CE-20 was the realistic key factor for LVM-3/GSLV-mk3 in short term ...this first show approved it has achieved the goal...
ISRO seems satisfied with it and the whole rocket...they are confident to plan a 0.5 ton payload increase in the next mission in 2018 via parameter adjustment of L-110 and C-25 stages .
----------
the live broadcast indicated the CE20 real performance deviated a little bit from the desired curve
View attachment 16599
CE 20 did not under-performed, but it over performed. Algorithm glitch might have overcompensated by shutting CE 20 bit early, thats what seem to have happened. Algorithms might need bit of fine tuning.

What you said two years ago, was said eons ago by ISRO and understood eons ago by Indic aficionados for space tech. Nothing new.
 

Prayash

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Isro: How calculated risks have translated into more frequent and sophisticated launches.

Employees at the Indian Space Research Organisation (Isro) do not open champagne bottles to celebrate success. As soon as a rocket launch is over, they go back to their offices and start working on the next launch. About two years ago, Isro decided that this practice was not good enough. No, they weren’t yearning for the bubbly. Rather, the organisation was keen to begin assembling the next rocket well before a specific launch was over. So, it created teams and processes to that end.

The successful launch of the Geostationary Launch Vehicle (GSLV) Mark III on Monday was a major milestone in Isro’s five-decade history. A similar success would have resulted in celebrations in some space agencies around the world. But, on Tuesday morning, employees at the Satish Dhawan Space Centre (Shar) in Sriharikota were back to working on the half-assembled Polar Satellite Launch Vehicle (PSLV) C-39, which will soon be assembled fully and launched on June 23. “Earlier the entire Shar used to concentrate on one mission,” says director P Kunhikrishnan. “Now we work in parallel to increase the throughput.”

By the end of this month, Isro would have made four rocket launches this year itself. Two of them were technically challenging, one being GSLV Mark III and the other the launch of 104 satellites on one rocket. By the month-end, Isro would also have built four satellites this year. They include the Gsat-19, a sophisticated satellite with high throughput that is expected to improve communication significantly in the country. It was put into orbit on Monday by the GSLV Mark III.

Even a casual observer would have noticed that the frequency of Isro’s missions has been increasing in recent times. Isro is also tackling missions of increasing sophistication, and slowly reducing the gap between India and the other space powers. Early next year, Isro will launch its second lunar mission, consisting of an orbiter, lander and rover.

If the government gives its approval, Isro will also begin work on a human mission sometime soon. With two different rockets and a third to be available soon, Isro will have an increasing presence in the global commercial market. When current chairmanKiran Kumar took over two and a half years ago, Isro was in good shape from a technical perspective.



The Mars mission had been accomplished and the GSLV, a thorn in Isro’s flesh for a long time, had been successfully flown. A cryogenic engine had been developed, and a human crew capsule tested by atmospheric re-entry. Through all these, the PSLV had been launching satellites with exquisite precision.

This was not always the case, as Isro went through a difficult phase about seven years ago. A GSLV launch failed and a cryogenic engine shut off prematurely. Another mission was aborted due to a fuel leak. “When you encounter difficulties,” says Kiran Kumar, “the concentration of the people goes towards solving those problems. But, once these problems are solved, the concentration is on how we can make things happen at a faster pace.”

The technical problems had delayed Isro’s programmes significantly. The GSLV should have been ready by 2009, but its first successful flight was only in 2014. The cryogenic engine should have been ready early in the millennium, but it was successfully flown only in 2014. Even the PSLV had a backlog. The government was aware of the problems, but continued to support the organization.

Soon after he took over, Kumar reengineered Isro to work faster. The senior management sat down and identified the bottlenecks. They strengthened the technical review system. They also optimized procurement and methods of testing. Separate divisions were created to deal with operations and R&D.

Projects were done in parallel. “The chairman asked us to push ourselves to the limit,” says S Somanath, director of the Liquid Propulsion Systems Centre (LPSC) in Thiruvananthapuram. The results were evident soon. The launches increased in frequency.

The backlog of satellites and launches has decreased, but national requirements are so large that Isro will be kept busy for a long time. The commercial opportunities are also not insignificant. “There is a shortage of launchers, whether it is higher capacity of lower capacity,” says Kumar. Isro, especially in the current high-speed environment, has the ability to respond quickly to market needs.

With PSLV launches increasing in frequency, satellite builders get opportunities for launch with low turnaround time. Isro’s launch costs also go down. None of these would have been possible if the technical problems had been left unsolved. In its nine-year history, GSLV Mark I and II together had notched five failures till December 2010. After Mark I failed in December 2010, Isro took two years before trying the next launch. In August 2013, GSLV Mark II flight was aborted due to a fuel leak. These failures delayed GSLV Mark III as well, as its facilities were used for Mark II for some time.

Isro subsequently did such thorough analysis of the GSLV that some of its engineers had said that they would not have known what to do if it had failed again in 2014. Its successful flight in January 2014 was a major turnaround for Isro. The preceding years were the period when Isro engineers mastered several technology areas, including the cryogenic engine, and developed confidence to take more risks. It also grabbed world attention through the mars mission. “Two successful GSLV launches showed that whatever we worked out was successful,” says Kumar. “Technology is no longer an issue.” He could look at more challenging problems from 2015 onwards.

Isro now became very serious about adhering to the fixed launch date. Launch dates became sacrosanct. Only a newly-formed project management council had the right to change a launch date, and that too when done well in advance. Once Isro became serious about not changing the launch date, work culture changed for the better. People picked up speed. “In the aerospace sector, there is a belief that we should not hurry,” says Somanath. “But we can do faster. By doing things faster, nothing bad is going to happen.”

Isro then looked at its testing methods and decided to optimise them. Launch vehicle components were being tested in Thiruvanathapuram, transported to the launch centre at Sriharikota and then tested again. Isro decided to test them only at Sriharikota, thereby saving time. “We took a calculated risk,” says K Sivan, director of theVikram Sarabhai Space Centre in Thiruvananthapuram.

If the components were found to be faulty during tests at Shar, Isro would have lost more time. However, engineers at VSSC by now have the confidence in their skills to take this risk. The biggest changes were reserved for Shar, which got big investments to create new facilities. Shar also started activities in parallel. It had built a solid stage assembly building, exclusively meant for GSLV Mark III.

This rocket had big solid motors – the third largest in the world – that could not be made by industry, and needed these special facilities for assembly. Isro also decided that the assembly building would be used for PSLV assembly as well. When the solid stage assembly building was being used for multiple vehicles, two vehicles could be assembled in parallel. Earlier the practice was to launch a rocket, clean up and repair the launch pad in about three weeks, and then start the new assembly. Now vehicles are assembled in parallel without affecting each other. Shar is building a third vehicle assembly bay that will be ready by the end of the year, and it will increase the efficiency even more.

Isro has two launch pads. From the first pad, it can launch six PSLVs. When the third assembly bay is ready, the throughput from the second launch pad will increase to ten, or probably 12 when teams are stretched fully. It means that Isro can have 18 launches from next year onwards.

Its launch capacity will remain at this level till it builds a third launch pad. Isro now has an extremely reliable vehicle in PSLV, which is being used by many satellite builders for launch. GSLV Mark II is now operational, and so Isro has a second vehicle for commercial launches. GSLV Mark III will be declared operational after one more flight, scheduled to happen after a year. It can launch satellites of up to 4,000 kg in weight.


As Isro developed more powerful launch vehicles, the weight of communication satellites kept going up. However, electric propulsion in satellites is promising to bring down their weight in the near future. So the GSLV Mark III will enter a lucrative commercial market soon. Big rockets are not optimized to launch 4-5-tonne satellites.

Arianspace, whose Ariane 5 rocket can launch payloads of more than ten tonnes, is now developing Ariane 6 for launching satellites of around five tonnes. So the two GSLV vehicles are addressing a market that may not go away soon. “I am confident that the GSLV Mark III will have a long life,” says K Radhakrishnan, former chairman of Isro.

Over the next few years, Isro is planning to start a joint venture with private industry to launch vehicles and make satellites. Isro itself is going to concentrate on future challenges, leaving the routine jobs to the joint venture. This entity is expected to start work by 2021. Isro’s biggest challenge after that will be to take humans to space.

source:http://m.economictimes.com/news/sci...phisticated-launches/articleshow/59043451.cms
 
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Prayash

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Navigation satellite clocks ticking; system to be expanded: ISRO
By IANS | Updated: Jun 10, 2017, 03.02 PM IST

NavIC with only one rubidium atomic clock switched on instead of two in the six satellites.

The phrase signals that the atomic clocks - that provide locational data - in the sixnavigation satellites are functioning normally.

Three atomic clocks in the first navigation satellite IRNSS-1A have already failed."

The clocks are ticking well. It's not possible to share the technical details of mission management for important reasons. ISRO is adopting various strategies so that best results are obtained from its satellite systems," A.S. Kiran Kumar, Chairman, Indian Space Research Organisation (ISRO) told IANS on Saturday over phone.

Sources close to ISRO, on the condition of anonymity, told IANS that two more atomic clocks in the satellite system started showing abnormalities thereby taking the total number of failed clocks to five.

"Hence as a precaution and also to extend the operational life of satellites, the ISRO is running the NavIC system with one clock switched on instead of two. If the running clock fails then the standby clocks will be switched on," sources said.

The initial plan was to keep two clocks in the satellite on while keeping the third one on standby.

Simply put, the Indian Regional Navigation Satellite System (IRNSS) is similar to the GPS (Global Positioning System) of the US, Glonass of Russia, Galileo of Europe and China's Beidou.

Each satellite has three clocks and a total of 27 clocks for the navigation satellite system (including the standby satellites) were supplied by the same vendor.

The clocks are important to provide precise locational data.
"The clocks are working well. The signals are good. The replacement satellite for IRNSS-1A will be sent up this year. Already our system is giving precise data even in areas populated with dense buildings and forest areas," said Tapan Misra, Director, Space Applications Centre, ISRO.

According to him, space sector is an unforgiving business and hence mission management is important.

Misra said it is not only the atomic clocks in the Indian satellite navigation systems that have failed, the clocks in the European system Galileo too have failed as per reports.

The Indian space agency has signed up with several universities in the country to measure the performance of NavIC system, said Misra.

The Rs 1,420 crore Indian satellite navigation system NavIC consists of nine satellites -- seven in orbit and two as substitutes.

"We are already using the NavIC system for several applications. The replacement satellite for IRNSS-1A will be launched in July or August. There are also plans to expand the NavIC system by taking the number of satellites to 11 from seven," Kumar said.

It is learnt that ISRO has got the atomic clocks replaced in the two standby NavIC satellites.

Starting July, 2013, the Indian space agency has launched seven navigation satellites. The last one was launched on April 28, 2016. Each satellite has a life span of 10 years.

The NavIC system was performing well till the three clocks in IRNSS-1A -- the first satellite -- failed some months back.
 
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mahesh

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You do realize that it shutoff 20s before nominal, because of achieving required rel. vel faster ?
The satellite was said to be around 1000 kms below from the expected orbit which was said to be linked to the 'over performance' the cryogenic engine. And later was gain during orbital raising.

Sent from my irisX8 using Tapatalk
 

Prayash

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Source:http://www.isro.gov.in/first-developmental-flight-of-gslv-mk-iii
The first developmental flight of GSLV-Mk-III
With the successful first developmental flight - GSLV Mk-III D1, carrying the high through put satellite GSAT-19, India has achieved self-reliance in launching 4 ton class satellite to Geosynchronous Transfer Orbit (GTO).

With the current fleet of operational launch vehicles namely PSLV and GSLV, India can meet the requirements of launching communication satellites up to 2.2 tons to GTO. With the introduction of GSLV Mk-III, the payload capability has been doubled which will meet the national requirement of launching communication satellites.

GSLV Mk-III is a three stage vehicle designed for catering the need of carrying heavier communication satellite to GTO. The vehicle lift off mass is 640 ton with overall height of 43.498 m and core diameter of 4 m. The vehicle has two Solid Strap-on motors - S200, a core liquid booster stage - L110, and a cryogenic upper stage - C25. To accommodate heavier payloads, 5 m diameter Ogive Payload Fairing is employed.

S200 strap on motor is a 3.2 m diameter solid motor. It is made up of 3 motor segments and has a flex nozzle control system. To reduce the disturbance moment due to differential thrust between the two S200 strap on motors in flight, the two motors are processed as a pair during the motor segments casting. L110 liquid Stage, works on two clustered Vikas engines which are being used in PSLV & GSLV. It has 110 tons of propellant loading and each of the twin engines produces 80 tons of thrust. The upper stage in GSLV MK-III vehicle is cryogenic stage with 28 tonnes of propellant loading and designated as C25. The C25 Stage is powered with a 20 ton thrust (nominal) engine working on Gas Generator (GG) cycle. C25 stage is a high performance cryo stage carrying a propellant combination of liquid Hydrogen stored at 20 K and liquid Oxygen stored at 77 K. C25 Engine & stage were developed and validated through a series of 200 tests which included qualification tests through a step by step process of component level test, engine level test for a duration of 800 s and stage level test for a duration of 640s equal to its flight time. Unlike the Cryogenic Upper Stage (CUS) of GSLV, which was based on the Russian engine design, C25 is entirely indigenous starting from configuration, design, development and qualification strategies. The entire test programme of integrated C25 Engine & stage were done in fast track mode and completed in a short time frame of two years using limited number of hardware and optimal sequencing of tests. During the maiden flight of GSLV Mk-III on June, 5 2017 the vehicle carried the GSAT-19 satellite onboard, weighing 3,136 kg, to the targeted GTO of 170km by 36,000km.

The vehicle lifted off from the launch pad upon the simultaneous ignition of both S200 motors. L110 core stage ignited during S200 thrusting phase itself at 112.66 s after lift off to augment the thrust of the vehicle and continued to function beyond the separation of two solid strap-ons which occurred at 140.84s from lift off. After nearly 206 s of firing, L110 stage separated followed by the ignition of C25 cryogenic stage. C25 stage operated for around 625 s duration and once the required orbital conditions were achieved, the cryogenic stage shut off the engine. Then the GSAT-19 satellite was injected into GTO. The performance of the two paired S200 motors were as predicted during flight and the differential thrust between the motors was benign. L110 stage performed exactly as per prediction & the performance of the twin clustered Vikas engines was identical. It is to be noted that even though GSLV Mk-III D1was the second flight as far as the S200 and L110 are concerned, for the newly developed C25 stage this was the maiden flight. The performance of the C25 stage in this maiden flight was as per prediction, which establishes the capability of ISRO to predict the flight performance in advance.

The experimental flight of GSLV Mk-III (LVM3-X) was undertaken on December 18, 2014 with S200 and L110 stages to demonstrate the atmospheric regime of the flight and unique features in GSLV Mk-III, compared to other launch vehicles, including the differential thrust between the two S200 solid strap-ons.

Based on the flight data analysis of LVM3-X mission, suitable improvements have been incorporated in GSLV Mk-III vehicle configuration, mainly on aerodynamic shaping, which included Ogive shaped Payload Fairings, Slanted Nose Cones for S200, aero shaping of cowlings & shrouds and closed Inter-Tank Structure for C25 stage. This has helped in improving the vehicle robustness, with better aerodynamic margins and reduced overall acoustic levels. Modification in S200 motor Head End Segment grain configuration was also done to reduce the dynamic pressure during flight. All these changes were qualified through ground tests as well as detailed characterisation tests and were incorporated in GSLV MK-III D1 vehicle.

With the successful completion of the first development flight, ISRO now gears up for the second development flight - GSLV Mk-III D2 with augmented payload capability so that the first operational flight of GSLV MK-III will carry around 4000 kg payload to GTO. The strategies/technologies for achieving the above capabilities are identified and ISRO is working towards perfecting these technologies before implementation in the flight.

Success of the first development flight of GSLV Mk III on June 05, 2017 is indeed a rare feat.

 

happylion

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^ No it was not a 1000 Kms off etc. The fuel time for the small correction was an extra 4 seconds of the LAM motor.. This is a developmental flight so the data obtained will be used to calibrate variious subsystems to correct things obtained/assumed during simulation studies.
 

Prayash

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Jun 08, 2017
The first orbit raising operation of GSAT-19 Satellite has been successfully carried out by LAM Engine firing for 116 sec from 14:03 hr IST on June 06, 2017.
Orbit Determination results from this LAM firing are:

Apogee X perigee height was changed to 35938 km X 172.77 km.
Inclination is 21.56 deg.
Orbital period is 10 hr 33 min.

Jun 08, 2017
The second orbit raising operation of GSAT-19 Satellite has been successfully carried out by LAM Engine firing for 5538 sec from 15:44 hr IST on June 07, 2017.
Orbit Determination results from this LAM firing are:

Apogee X perigee height was changed to 35840 km X 10287 km.
Inclination is 7.02 deg.
Orbital period is 13 hr 58 min.
June 10,2017
The third orbit raising operation of GSAT-19 Satellite has been successfully carried out by LAM Engine firing for 3469 sec from 09:55 hr IST on June 09, 2017

Orbit Determination results from this LAM firing are:


    • apogee X perigee height was changed to 35875 km X 30208 km.
    • Inclination is 0.793 deg.
    • Orbital period is 21 hr 38 min
June 10,2017
The fourth and final orbit raising operation of GSAT-19 Satellite has been successfully carried out by LAM Engine firing for 488 sec from 07:59 hr IST on June 10, 2017

Orbit Determination results from this LAM firing are:

  • apogee X perigee height was changed to 35869 km X 35470 km.
  • Inclination is 0.101 deg.
  • Orbital period is 23 hr 50 min 10 sec
 
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happylion

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The satellite will be in drifting orbit to reach its parking slot. It has reached all parameters for its Gestationary orbit.
 

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