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ЦитироватьTHIRUVANANTHAPURAM: Soon after the successful launch of PSLV-C38 on Friday at 9.29 am, the Isro team, including scientists from Vikram Sarabhai Space Centre (VSSC) and Liquid Propulsion Systems Centre (LPSC), returned here the same day evening. The scientists led by VSSC director K Sivan indicate that the focus will be on the launch of the next PSLV-C39 in August first week.

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Ahead of the next PSLV-C39 launch to place a navigational satellite in orbit, it is planned to launch a communication satellite GSAT-17 from French Guiana this June 28, ISRO chairman AS Kiran Kumar told TOI.

"Among the two more PSLV launches planned this year include PSLV-C39 by August first week. Then GSLV-Mk II launch is planned by December and GSLV-MK III by early next year. It is also planned to launch one more communication satellite GSAT-11 from French Guiana in December this year," he said.

On the reason to launch Indian satellites from France despite ISRO's prowess, he said though it is expensive to launch our satellites from other countries, it would take some more time to launch heavy satellites weighing over 3.2 ton that too soon after the recent launch of 104 satellites on board PSLV-C37 this Feb 15. The launch of GSAT satellites from French Guiana was slated earlier, he said. The 3425 kg GSAT-17 and 5725 kg GSAT-11 are communication satellites expected to boost internet services of digital India.

On the success of PSLV-C38 mission, he said all the 31 satellites separated successfully including the first satellite Cartosat-2 series at 505 km sun synchronous orbit in 16 mins 43 seconds after lift-off and the last satellite was injected into orbit in 23 minutes.

After three stages of the launch vehicle burn out that falls into the sea, in the fourth stage of the launch vehicle at 505 km it placed the satellite into orbit. Then the vehicle continues to orbit around the earth, so to bring down at a lower orbit of 350 km, it is controlled by two retro-booster firings for restarts. Third re-start of the fourth stage of the vehicle will be controlled tonight to bring down the orbital velocity and change its inclination with respect to the equator, so that launch vehicle which is of no utility value is burnt out neutralising the fuel left out, Isro chairman Kiran Kumar said.

"It was a 100 percent successful launch of PSLV-C38 in placing the 31 satellites including 29 satellites from other countries." VSSC director K Sivan told TOI on Friday. Now, the focus is on the next PSLV-C39 launch in August first week to place the navigational satellite IRNSS-1H in orbit, he said.

While, Liquid Propulsion Systems Centre (LPSC) director S Somnath said the Cartosat-2E is the third satellite of the Cartosat-2 series. With this launch, Cartosat-2 series constellation is complete. It is intended for fast, repetitive earth observation, cartography or mapping and information dissemination. Further, the focus is to launch the navigational satellite IRNSS-1H on board PSLV-C39.

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PSLV-C39/IRNSS-1H Mission

The next mission, PSLV-C39 will launch IRNSS-1H navigation satellite, scheduled in August 2017. IRNSS-1H will augment the existing seven satellites of NavIC constellation.

(https://forum.novosti-kosmonavtiki.ru/forum/file/72668)

ЦитироватьIndian Space Research Organisation (ISRO) will launch its Navigation satellite IRNSS-1H by the end of this month to augment the existing seven satellites of NavIC constellation, a senior ISRO official said.

To be launched on board PSLV-C39, IRNSS-1H will be a "back up" navigation satellite for IRNSS-1A, one among the seven satellites in the constellation, as its three rubidium atomic clocks on board had stopped functioning.

"IRNSS-1H on board PSLV-C39 will be launched by the end of this month. The exact date will be decided shortly," a senior ISRO official told PTI. He said IRNSS-1H will be a back up for IRNSS-1A, whose three "imported atomic clocks had failed".

Спойлер

The Indian Regional Navigation Satellite System (IRNSS) is an independent regional navigation satellite system developed by India on par with US-based GPS.

The system that offers services like terrestrial and marine navigation, disaster management, vehicle tracking and fleet management, navigation aide for hikers and travellers, visual and voice navigation for drivers, was named as 'NavIC' (Navigation with Indian Constellation) by Prime Minister Narendra Modi.

ISRO had launched seven satellites - IRNSS-1G on April 28, 2016, IRNSS-1F (March 10, 2016), IRNSS-1E (January 20, 2016), IRNSS-1D (March 28, 2015), IRNSS-1C (October 16, 2014), IRNSS-1B (April 4, 2014) and IRNSS-1A on July 1, 2013.

According to ISRO officials, the total cost of all the seven satellites was Rs 1,420 crore.

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Цитировать31న పీఎస్‌ఎల్వీ–సీ39 ప్రయోగం
Sakshi (http://www.sakshi.com/topic/sakshi) | Updated: August 04, 2017 00:57 (IST)

శ్రీహరికోట(సూళ్లూరుపేట): శ్రీపొట్టి శ్రీరాములు నెల్లూరు జిల్లా లోని సతీష్‌ ధావన్‌ స్పేస్‌ సెంటర్‌(షార్‌) నుంచి ఈ నెల 31న పీఎస్‌ఎల్వీ–సీ39 ఉపగ్రహ వాహక నౌకను ప్రయోగించేందుకు ఇస్రో శాస్త్రవేత్తలు సన్నద్ధమవుతున్నారు. దీని ద్వారా ఇండియన్‌ రీజినల్‌ నావిగేషన్‌ శాటిలైట్‌ సిస్టమ్‌ (ఐఆర్‌ఎన్‌ఎస్‌ఎస్‌) ఉప గ్రహాన్ని రోదసీలోకి పంపేందుకు ఏర్పాట్లు చేస్తున్నారు. ఈ నెల 10 నుంచి 15లోపు బెంగళూరు నుంచి ఉపగ్రహం షార్‌కి వచ్చే అవకాశముంది.

స్వదేశీ సాంకేతిక పరిజ్ఞానంతో భారత్‌కు దిక్సూ చి వ్యవస్థను అందుబాటులోకి తెచ్చేందుకు 7 ఇండియన్‌ రీజినల్‌ నావిగేషన్‌ శాటిలైట్లను రోదసీలోకి పంపగా, అందులో ఒకటి సేవలను అందించడం మానేసింది. దానిస్థానంలో ఈ నెల 31న మరో ఉపగ్రహన్ని పంపేందుకు సన్నాహాలు చేస్తున్నారు.
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ЦитироватьPSLV-C39 experiment on 31st
Sakshi | Updated: August 04, 2017 00:57 (IST)

SRIHARITOTA (SULULARUPETA): Scientists at ISRO are getting ready to launch the PSLV-C39 satellite launcher on the 31st of August, from the Satish Dhawan Space Centre. The rocket will carry an Indian Regional Navigation Satellite System (IRNSS) satellite to orbit. The satellite is expected to reach SHAR from Bengaluru between the 10th and 15th of this month.

Apart from conducting research, ISRO also tries to provide navigation services to the nation. To this end, they have launched seven IRNSS satellites. However, one of them has stopped functioning. The upcoming launch on the 31-st of August is meant to replace that satellite.
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ЦитироватьЭксперимент PSLV-C39 на 31-е
Sakshi | Обновлено: 04 августа 2017 00:57 (IST)

ШРИХАРИТОТА (Сулуларупета): Ученые из ISRO собираются запустить спутниковую носитель PSLV-C39 31 августа из Космического центра Сатиша Дхавана (SHAR) в районе Неллор. Ракета выведет на орбиту спутник индийской региональной навигационной спутниковой системы (IRNSS). Ожидается, что спутник прибудет в SHAR из Бенгалуру между 10-м и 15-м числом этого месяца.

7 индийских региональных навигационных спутников были отправлены в космос, причем один из них перестал предоставлять Индии услуги с использованием местных технологий. На данный момент планируется отправить другой спутник 31-го числа этого месяца.
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ЦитироватьIndia to launch spare navigation satellite August-end

Aug 10, 2017, 08.17 PM IST

Bengaluru, Aug 10 (IANS) India will launch its eighth navigation satellite this month-end as a spare or back-up for its constellation in the geo-orbit, a top space agency official said on Thursday.

"We are preparing to launch the eighth Indian Regional Navigation Satellite System (IRNSS-1H) at the end of this month as a standby for the Navigation Indian Constellation (NavIC), which is operational for services," ISRO Satellite Centre Director M. Annadurai told IANS here.

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The 1.4-tonne satellite will be launched fr om the state-run Indian Space Research Organisation's (ISRO) spaceport at Sriharikota off the Bay of Bengal in Andhra Pradesh, about 80 km northeast of Chennai.

"The satellite is ready to move from our centre to Sriharikota on August 12 on a special vehicle for integration with the rocket at the space centre," said Annadurai on the margins of a technology event.

The launch authorization board will decide on the date and time after all the checks were completed during the window for the launch schedule.

The space agency, however, will use a medium Polar Satellite Launch Vehicle (PSLV C39) with four strap-on motors to deploy the satellite first in the geo-transfer orbit and later in the geo-stationary orbit, about 36,000 km above the earth, wh ere the NavIC is orbiting over the last four years.

"The spare or standby satellite will also make up for the non-functioning of the three rubidium atomic clocks on board the first one (IRNSS-1A) and one each in the other two NavIC satellites," ISRO's Vikram Sarabhai Space Centre Director K. Sivan told IANS from Thiruvananthapuram.
 
Clarifying that the spare satellite (IRNSS-1H) would augment the NavIC's operations, Sivan said IRNSS-1A would continue to orbit and provide the services it is programmed for the intended users as part of the system.

"We are not going to abandon the first one (IA) as it working well with all its functions except the atomic clocks being normal. In the other satellites, we are using only one clock, as other two are for redundancy," said Sivan.

The clocks provide precise locational data for the users.

The first one was launched in July 2013 and the seventh one (IRNSS-1G) in April 2016.

The multi-purpose satellite-based positioning system, akin to the American GPS, Glonass of Russia, Galileo of Europe and China's Beidou, supports vehicle tracking, fleet management, disaster management and mapping services besides terrestrial, marine and aerial navigation in the sub-continent.

The space agency plans to launch an additional space navigation satellite later this year to augment the services of the Rs 1,420 crore NavIC.

"The two spare navigation satellites will make up for any shortfall in the operations and service provided by NavIC to the users round-the-clock over the next 10 years," added Sivan.

NavIC provides two types of services -- standard positioning service and restricted service. The former is for all users while the latter is an encrypted service for only authorised users.
 
 --IANS

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ЦитироватьCHENNAI: India will launch a backup navigation satellite this month end as a replacement for the IRNSS-1A satellite whose three atomic clocks have failed. Reliable sources say the launch is tentatively fixed for August 31 on board PSLV-C39.

Indian Space Research Organisation (ISRO) chairman A S Kiran Kumar confirmed to the Express that the launch would happen this month end, but said the exact date hadn't been finalised yet.

Спойлер

The Rs 1,420 crore satellite navigation system NavIC suffered a setback in January last, when three rubidium atomic clocks of IRNSS-1A that was put into orbit on July 1, 2013, stopped working. Each satellite has three clocks and a total of 27 clocks for the navigation satellite system were supplied by the same vendor from Europe. The clocks are important to provide precise data.

ISRO officials maintain that the navigation services were not affected.

"Four satellites are enough to deliver robust navigation services. Even if IRNSS-1A is taken off the NavIC constellation, six are still operational. As per the original plan, we have two spares ready for contingency measures. So, one of them is being flown out this month," a senior official said.

NavIC is an independent regional navigation satellite system developed by India. It is designed to provide accurate position information service to users in India as well as the region extending up to 1,500 km from its boundary.

All satellites of the NavIC constellation are configured identically with I-1K Bus to be compatible for launch onboard PSLV.

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IRNSS-1H spacecraft has been flagged off to SDSC-SHAR launch pad on 11-Aug-2017

(https://img.novosti-kosmonavtiki.ru/230351.jpg)

(https://img.novosti-kosmonavtiki.ru/230352.jpg)

Цитироватьనెలాఖరులో పిఎస్‌ఎల్‌వి-సి39 ప్రయోగం
Published Sunday, 13 August 2017
 
(https://img.novosti-kosmonavtiki.ru/222712.jpg)

సూళ్లూరుపేట, ఆగస్టు 12: భారత అంతరిక్ష పరిశోధన సంస్థ (ఇస్రో) మరో నావిగేషన్ ఉపగ్రహ ప్రయోగానికి సన్నద్ధమవుతోంది. భారత అంతరిక్ష ప్రయోగ కేంద్రం సతీష్ థావన్ స్పేస్ సెంటర్ షార్ కేంద్రం నుంచి ఈ నెలాఖరులో పిఎస్‌ఎల్‌వి-సి 39 రాకెట్ ప్రయోగం జరిపేందుకు ఇస్రో శాస్తవ్రేత్తలు సన్నాహం చేస్తున్నారు. ఈ రాకెట్ ద్వారా కక్ష్యలోకి పంపే ఐఆర్‌ఎన్‌ఎస్‌ఎస్-1హెచ్ ఉపగ్రహం బెంగళూరులోని ఉపగ్రహ తయారీ కేంద్రం నుంచి శనివారం రోడ్డు మార్గాన అత్యంత భారీ భద్రత నడుమ షార్‌కు చేరింది. ఇప్పటికే షార్‌లోని రెండో ప్రయోగ వేదిక వద్ద రాకెట్ అనుసంధాన పనులు శరవేగంగా జరుగుతున్నాయి. రాకెట్ మూడు దశల అనుసంధాన పనులు పూర్తయిన తరువాత ఉపగ్రహాన్ని అమర్చి ప్రయోగానికి సిద్ధం చేయనున్నారు. ఇస్రో వర్గాల సమాచారం మేరకు ఈ నెల 31న రాకెట్ ప్రయోగం ఉండవచ్చని తెలుస్తోంది.

ЦитироватьPSLV-C39 experiment at the end of month

SULULARUPETA, AUGUST 12: Indian Space Research Organization (ISRO) is preparing for another Navigation satellite experiment. ISRO scientists are planning to launch a PSLV-C 39 rocket from the Indian Satish Dhawan Space Center SHAR. The IRNSS-1H satellite, which will sent to orbit by the rocket, came to SHAR from the satellite manufacturing facility in Bangalore on Saturday with the highest security. Rocket connectivity is already going on at the second launch platform in SHAR. Once the rocket is completed three phase of connectivity, the satellite will be set up and ready for use. According to information from ISRO, the rocket experiment may have been on the 31st of this month.

ЦитироватьЗапуск PSLV-C39 в конце месяца

Шрихарикота, 12 августа: Индийская организация космических исследований (ISRO) готовится к запуску навигационного спутника. Ученые ISRO планируют запустить ракету PSLV-C 39 из индийского космического центра им. Сатиша Дхавана SHAR. Спутник IRNSS-1, который будет отправлен на орбиту ракетой, прибыл в SHAR из спутникового производства в Бангалоре в субботу с самой высокой безопасностью. Сборка ракеты уже идет на второй стартовой платформе в SHAR. После того как будут завершены три этапа сборки ракеты, спутник будет установлен и готов к использованию. Согласно информации ISRO, ракетный эксперимент, возможно, будет 31-го числа этого месяца.

ЦитироватьVOMF

A1683/17 (Issued for VOMF PART 1 OF 2) - PSLV C39 ROCKET LAUNCH FM SHAR RANGE, SRIHARIKOTA WILL TAKE PLACE AS PER FLW DETAILS.
THE LAUNCH WILL BE ON ANY ONE OF THE DAY DRG THIS PERIOD. ACTUAL DATE OF LAUNCH WILL BE INTIMATED 24HR IN ADVANCE THROUGH A SEPERATE NOTAM.
LAUNCH PAD COORD: 134312N 0801348E
NO FLT IS PERMITTED OVER THE DNG ZONE.
A. DNG ZONE -1 IS A CIRCLE OF 10NM AROUND THE LAUNCHER
B. DNG ZONE -2 IS A RECTANGULAR AREA BOUNDED BY:
1330N 08030E 1350N 08035E 1335N 08130E 1315N 08125E
C. DNG ZONE -3 IS A RECTANGULAR AREA BOUNDED BY:
1300N 08210E 1330N 08215E 1255N 08405E 1225N 08400E
D. DNG ZONE -4 IS A RECTANGULAR AREA BOUNDED BY:
1220N 08405E 1300N 08415E 1245N 08510E 1205N 08500E
E. DNG ZONE -5 IS A RECTANGULAR AREA BOUNDED BY:
1110N 08825E 1145N 08835E 1125N 08940E 1050N 08930E
F. DNG ZONE -6 IS A RECTANGULAR AREA BOUNDED BY:
0905N 09450E 0955N 09505E 0935N 09600E 0845N 09545E
G. DNG ZONE -7 IS A RECTANGULAR AREA BOUNDED BY:
1900S 13400W 1700S 13400W 1300S 11200W 0730S 09000W
0930S 09000W 1500S 11200W
ROUTES AFFECTED IN CHENNAI FIR ARE:
N571, N877, P761, P762, W20, A465, P628, Q10, Q11, Q23, Q24, V3, V4, V9 AND V11
CLOSURE/ALTN ROUTINGS:

//PART 1 OF 2 PARTS//. BTN 1200-1600, 31 AUG 12:00 2017 UNTIL 18 SEP 16:00
2017. CREATED: 22 AUG 08:46 2017

ЦитироватьAug 23, 2017

PSLV-C39/IRNSS-1H Mission is scheduled to be launched on Aug 31, 2017 at 18:59 Hrs from SDSC SHAR, Sriharikota.

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PSLV-C39/IRNSS-1H Mission Gallery

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(http://www.isro.gov.in/sites/default/files/styles/gallery_thumb/public/galleries/PSLV-C39/IRNSS-1H%20Mission%20Gallery/10irnss-1hspacecraftintegratedwithpslv-c39.jpg?itok=zANWO3xU) (http://www.isro.gov.in/sites/default/files/galleries/PSLV-C39/IRNSS-1H%20Mission%20Gallery/10irnss-1hspacecraftintegratedwithpslv-c39.jpg) (http://www.isro.gov.in/sites/default/files/styles/gallery_thumb/public/galleries/PSLV-C39/IRNSS-1H%20Mission%20Gallery/9irnss-1hincleanroomatsdscshar.jpg?itok=ecklk1tR) (http://www.isro.gov.in/sites/default/files/galleries/PSLV-C39/IRNSS-1H%20Mission%20Gallery/9irnss-1hincleanroomatsdscshar.jpg) (http://www.isro.gov.in/sites/default/files/styles/gallery_thumb/public/galleries/PSLV-C39/IRNSS-1H%20Mission%20Gallery/8pslv-c39liquidstageatthevehicleassemblybuildingduringvehicleintegration.jpg?itok=bYnO2NRF) (http://www.isro.gov.in/sites/default/files/galleries/PSLV-C39/IRNSS-1H%20Mission%20Gallery/8pslv-c39liquidstageatthevehicleassemblybuildingduringvehicleintegration.jpg)

(http://www.isro.gov.in/sites/default/files/styles/gallery_thumb/public/galleries/PSLV-C39/IRNSS-1H%20Mission%20Gallery/7pslv-c39strap-onsarebeingassembledwithcorestage.jpg?itok=tz3BdZCv) (http://www.isro.gov.in/sites/default/files/galleries/PSLV-C39/IRNSS-1H%20Mission%20Gallery/7pslv-c39strap-onsarebeingassembledwithcorestage.jpg) (http://www.isro.gov.in/sites/default/files/styles/gallery_thumb/public/galleries/PSLV-C39/IRNSS-1H%20Mission%20Gallery/6hoistingofnozzelendsegmentofpslv-c39corestageduringvehicleintegration.jpg?itok=StBQK_uf) (http://www.isro.gov.in/sites/default/files/galleries/PSLV-C39/IRNSS-1H%20Mission%20Gallery/6hoistingofnozzelendsegmentofpslv-c39corestageduringvehicleintegration.jpg) (http://www.isro.gov.in/sites/default/files/styles/gallery_thumb/public/galleries/PSLV-C39/IRNSS-1H%20Mission%20Gallery/5nozzleendsegmentofpslv-c39corestagebeingplacedonthemobilelaunchpedestal.jpg?itok=WZO4f64F) (http://www.isro.gov.in/sites/default/files/galleries/PSLV-C39/IRNSS-1H%20Mission%20Gallery/5nozzleendsegmentofpslv-c39corestagebeingplacedonthemobilelaunchpedestal.jpg)

(http://www.isro.gov.in/sites/default/files/styles/gallery_thumb/public/galleries/PSLV-C39/IRNSS-1H%20Mission%20Gallery/4irnss-1hisundergoingilluminationtest.jpg?itok=uqrR7l1k) (http://www.isro.gov.in/sites/default/files/galleries/PSLV-C39/IRNSS-1H%20Mission%20Gallery/4irnss-1hisundergoingilluminationtest.jpg) (http://www.isro.gov.in/sites/default/files/styles/gallery_thumb/public/galleries/PSLV-C39/IRNSS-1H%20Mission%20Gallery/3irnss-1hatcleanroomwithoneofitssolarpanelsdeployed.jpg?itok=BHhXo5_Q) (http://www.isro.gov.in/sites/default/files/galleries/PSLV-C39/IRNSS-1H%20Mission%20Gallery/3irnss-1hatcleanroomwithoneofitssolarpanelsdeployed.jpg) (http://www.isro.gov.in/sites/default/files/styles/gallery_thumb/public/galleries/PSLV-C39/IRNSS-1H%20Mission%20Gallery/2irnss-1hisundergoingvibrationtest.jpg?itok=3m-EUb_A) (http://www.isro.gov.in/sites/default/files/galleries/PSLV-C39/IRNSS-1H%20Mission%20Gallery/2irnss-1hisundergoingvibrationtest.jpg)

(http://www.isro.gov.in/sites/default/files/styles/gallery_thumb/public/galleries/PSLV-C39/IRNSS-1H%20Mission%20Gallery/1irnss-1hincleanroom.jpg?itok=BSTpHM_x) (http://www.isro.gov.in/sites/default/files/galleries/PSLV-C39/IRNSS-1H%20Mission%20Gallery/1irnss-1hincleanroom.jpg)

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PSLV-C39/IRNSS-1H Mission

The next mission, PSLV-C39 will launch IRNSS-1H navigation satellite, on August 31, 2017. IRNSS-1H will augment the existing seven satellites of NavIC constellation.
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ЦитироватьISRO to launch a new navigation satellite on August 31

The IRNSS-1H, which will replace the IRNSS-1A, will be launched on board ISRO's work horse rocket the PSLV-C39 and the new satellite "will augment the existing seven satellites of NavIC constellation", ISRO said on Wednesday.

Written by Johnson TA (http://indianexpress.com/profile/author/johnson-t-a/) | Bengaluru | Published:August 24, 2017 8:07 am

(https://img.novosti-kosmonavtiki.ru/115319.jpg)
ISRO will launch a new navigation satellite into space on August 31 to replace the IRNSS-1A. (File)

The Indian Space Research Organization (ISRO) will launch a new navigation satellite into space on August 31 to replace the IRNSS-1A in a seven-satellite Indian navigation constellation following the failure of the IRNSS-1A due to deficiencies in three atomic clocks on the satellite that are crucial to providing positional information to users on earth.

Спойлер

The IRNSS-1H, which will replace the IRNSS-1A, will be launched on board ISRO's work horse rocket the PSLV-C39 and the new satellite "will augment the existing seven satellites of NavIC constellation", ISRO said on Wednesday.

Earlier this year, ISRO had stated that three Rubidium Atomic Frequency Standard (RAFS) clocks on the IRNSS 1A, the first of the seven IRNSS satellites that was launched on July 1, 2013, had malfunctioned, rendering the satellite ineffective. ISRO had originally indented for nine satellites in its Indian Regional Navigation Satellite System costing Rs 1,420 crore to service the global positioning data needs of the civilian sector and the Indian defence forces. While seven satellites were to form the Navigation Indian Constellation or NavIC, two satellites were meant to be replacements.

The atomic clocks in the new satellite are modified versions of the original clocks provided by an European supplier under a $4 million euro deal which were found deficient. Three similar clocks used in satellites for the European Galileo satellite system also reported similar problems.

ISRO has been carrying out modifications of clocks — procured fr om the European firm Spectratime — since 2008 to overcome technical issues. Investigations of malfunctioning clocks by the European Space Agency have revealed that a faulty component may be causing short circuits.

Спойлер

One of the primary reasons for the development of the indigenous Indian satellite navigation system like the IRNSS despite the existence of global systems like the Global Positioning System of the US, the Russian GLONASS, the European Galileo and the Chinese Beidou is the reliability that it offers when used for defence purposes. Accurate time keeping lies at the heart of navigation systems since the determination of a person's position on earth is subject to the accurate calculation of delays in signal transmission from the satellite to earth. Small errors in clocks can skew position data by several hundred kilometres.

On each of the IRNSS satellites there are three atomic clocks, with one acting as the primary time-keeper and the other two being in back-up mode. The failure of all three clocks on a satellite will render the satellite ineffective in providing positional information.

While three atomic clocks have failed on the 18 satellite European Galileo system, no satellite has been lost since the back-up clocks on the satellites have been in operation. "In recent months, a total of three RAFS clocks unexpectedly failed on Galileo satellites — all on Full Operational Capability satellites, the latest Galileo model. These failures seem to have a consistent signature, linked to probable short circuits, and possibly a particular test procedure performed on the ground," ESA stated in January this year.

ISRO started work on the Rs 1,420 crore IRNSS programme in 1999 after the Kargil war wh ere Indian defence forces could not use American GPS in the conflict zone to locate its soldiers.

The IRNSS positioning system is intended to provide two services — Standard Positioning Service (SPS) for general users and a Restricted Service (RS), which is an encrypted service provided only for authorised users like the defence forces.

NavIC is designed to provide accurate position information service to users in India as well as a region extending up to 1500 km from its boundary.

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Цитироватьఐఆర్‌ఎన్‌ఎస్‌ఎస్‌–1 హెచ్‌ ప్రయోగానికి రంగం సిద్ధం

Sakshi (http://www.sakshi.com/topic/sakshi) | Updated: August 23, 2017 03:38 (IST)

శ్రీహరికోట (సూళ్లూరుపేట): భారత అంతరిక్ష ప్రయోగ కేంద్రమైన సతీష్‌ ధావన్‌ స్పేస్‌ సెంటర్‌ (షార్‌) నుంచి ఈ నెల 31న ప్రయోగించ తలపెట్టిన ఇండియన్‌ రీజినల్‌ నావిగేషన్‌ శాటిలైట్‌ సిస్టం (ఐఆర్‌ఎన్‌ఎస్‌ఎస్‌–1 హెచ్‌) ఉపగ్రహాన్ని మంగళవారం పీఎస్‌ఎల్‌వీ సీ–39 రాకెట్‌కు అమర్చారు. 1,400 కిలోల బరువైన ఈ ఉపగ్రహాన్ని రాకెట్‌కు శిఖర భాగాన అనుసంధానించారు.
    
    అన్ని పరీక్షలు నిర్వహించి బుధవారం హీట్‌షీల్డ్‌ క్లోజ్‌ చేసే ప్రక్రియను పూర్తి చేయను న్నారు. 28న తుది విడత సంసిద్ధతా కార్యక్రమం నిర్వహి స్తారు. అనంతరం కౌంట్‌డౌన్‌ ప్రక్రియ ప్రారంభమవుతుంది. ఈ నెల 31 సాయంత్రం 6.59కి ప్రయోగాన్ని నిర్వహించాలని లక్ష్యంగా పెట్టుకున్నారు. ప్రయోగం తేదీని, సమయాన్ని తుదివిడత ఎంఆర్‌ఆర్‌ సమావేశంలో అధికారికంగా ప్రకటిస్తారు. 

ЦитироватьIRNSS-1H является полем для экспериментов

23 августа 2017 года 03:38 (IST)

Инкапсуляция завершена в понедельник (23-го). В среду (25-го) будет установлена тепловая защита. 28-го ожидается выпуск отчета о готовности к пуску (MRR), после чего начнётся обратеый отсчет времени до пуска в 18:59 IST 2017-08-31.

Цитироватьపీఎస్‌ఎల్‌వీ-సీ39 అనుసంధానం
 Posted On: Thursday,August 24,2017

శ్రీహరికోట: ...

మళ్లీ 27వ తేదీన ఉదయం వ్యాబ్‌ నుంచి ప్రయోగ వేదికకు రాకెట్‌ను తీసుకొస్తారు. ఇక్కడ కొన్ని పరీక్షలు నిర్వహించనున్నారు.
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ఈ దఫా రాకెట్‌ ప్రయోగానికి ముందుగా నిర్వహించే కౌంట్‌డౌన్‌ ప్రక్రియ 30 గంటలపాటు జరగనుంది. పీఎస్‌ఎల్‌వీ- సీ39 వాహకనౌక ఐఆర్‌ఎన్‌ఎస్‌ఎస్‌-1హెచ్‌ ఉపగ్రహాన్ని నింగిలోకి తీసుకెళ్లనుంది.

ЦитироватьШрихарикота:
...
Утром 27-го состоится вывоз ракеты из VAB на стартовую площадку.
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Процесс обратного отсчета для этого ракетного запуска будет начат за 30 часов до пуска
PSLV-C39 со спутником IRNSS-1H.

Цитироватьనేడు పీఎస్‌ఎల్వీ-సీ39 రిహార్సల్స్‌
28-08-2017 06:02:31
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శ్రీహరికోట సతీష్‌ థావన్‌ అంతరిక్ష కేంద్రం రెండో ప్రయోగవేదిక నుంచి పీఎస్‌ఎల్వీ-సీ39 రాకెట్‌ ద్వారా కక్ష్యలోకి ప్రవేశపెట్టేందుకు ఏర్పాట్లు పూర్తి చేసింది. షార్‌లోని వ్యాబ్‌లో రాకెట్‌తో ఉపగ్రహం అనుసంధానం ముగియడంతో ఆదివారం ఉదయం 6.30 గంటలకు రాకెట్‌ను శాస్త్రవేత్తలు రెండో ప్రయోగ వేదికపైకి చేర్చారు.
...

ЦитироватьToday is the PSLV-C39 rehearsals
28-08-2017 06:02:31
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The Sriharikota Satish Dhavan Space Center has completed arrangements to launch PSLV-C39 rocket from the second launch site. Scientists have put a rocket on the second launch pad at 6.30 am Sunday morning after satellite integration with the rocket.
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ЦитироватьСегодня проходят тренировки на PSLV-C39
28-08-2017 06:02:31
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Космический центр Сатиша Давана в Шрихарикоте завершил мероприятия по вывозу ракеты PSLV-C39 на вторую стартовую площадку. Ученые доставили ракету на вторую стартовую площадку в воскресенье в 6:30 утра, после установки спутника на РН.
...

Цитировать పీఎస్‌ఎల్వీ-సీ39 రిహార్సల్స్‌ విజయవంతం
29-08-2017 03:32:59

శ్రీహరికోట, ఆగస్టు 28: నావిక్‌ తొలి ఉపగ్రహంలో సాంకేతిక లోపం తలెత్తడంతో దాని స్థానంలో ఐఆర్‌ఎన్‌ఎస్‌ఎస్‌-1హెచ్‌ ఉపగ్రహాన్ని ప్రవేశపెట్టేందుకు ఇస్రో ఏర్పాటు పూర్తి చేసింది. ఈ నెల 31న శ్రీహరికోట సతీష్‌ థావన్‌ అంతరిక్ష కేంద్రం నుంచి పీఎస్‌ఎల్వీ-సీ31 ద్వారా దీన్ని కక్ష్యలో ప్రవేశపెట్టనుంది. ఈ ప్రయోగ సన్నాహాల్లో భాగంగా రెండో ప్రయోగ వేదికపై ఉన్న ఈ రాకెట్‌ ప్రయోగ రిహార్సల్స్‌ను సోమవారం శాస్త్రవేత్తలు దిగ్విజయంగా నిర్వహించారు. మంగళవారం మధ్యాహ్నం శాస్త్రవేత్తలు మిషన్‌ రెడీనెస్‌ రివ్యూ సమావేశం నిర్వహిస్తారు.

ЦитироватьPSLV-С39 успешная репетиция пуска
29-08-2017 03:32:59

Шрихарикота, 28 августа: ISRO создала спутник IRNSS-1 для замены первой спутниковой технологии NAVIC. Он будет запущен 31 августа на РН PSLV-C39 из космического центра Сатиша Давана. В понедельник учеными была проведена репетиция ракетного пуска. Во вторник днем ​​ученые проведут встречу с обзором готовности миссии.

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IRNSS-1H

IRNSS-1H will be launched into a sub Geosynchronous Transfer Orbit (sub-GTO) with a 284 km perigee and 20,650 km apogee with an inclination of 19.2 deg with respect to the equatorial plane. After injection into this preliminary orbit, the two solar panels of IRNSS-1H are automatically deployed in quick succession and the Master Control Facility (MCF) at Hassan takes control of the satellite and performs the initial orbit raising manoeuvres using the Liquid Apogee Motor (LAM) of the satellite, thereby finally placing it in its designated slot in the inclined Geosynchronous orbit.

While IRNSS-1H joins the constellation for providing navigation services, IRNSS-1A will be used for messaging services. IRNSS 1H comes with more flexibility in service and it is compatible with the satellites, which are in orbit.

Payloads: Like its other IRNSS predecessors, IRNSS-1G also carries two types of payloads – navigation payload and ranging payload. The navigation payload of IRNSS-1G will transmit navigation service signals to the users. This payload will be operating in L5-band and S-band. Highly accurate Rubidium atomic clocks are part of the navigation payload of the satellite. The ranging payload of IRNSS-1H consists of a C-band transponder, which facilitates accurate determination of the range of the satellite. IRNSS-1H also carries Corner Cube Retro Reflectors for laser ranging.

Launch of PSLV-C39/IRNSS-1H is Scheduled on Thursday, Aug 31, 2017 at 18:59 hrs from Satish Dhawan Space Centre, SHAR, Sriharikota

Launch Vehicle:
PSLV-C39/IRNSS-1H Mission

Type of Satellite:
Navigation

Manufacturer:
ISRO

Owner:
ISRO

Application:
Navigation

ЦитироватьAug 29, 2017

Mission Readiness Review (MRR) committee and Launch Authorisation Board (LAB) have cleared the 29hr countdown of PSLV-C39/ IRNSS-1H Satellite mission for Wednesday, Aug 30, 2017 starting at 14:00 hr IST, the launch of PSLV-C39/IRNSS-1H Satellite mission for Thursday, Aug 31, 2017 at 19:00 hr IST.

ЦитироватьLaunch of PSLV -C39/IRNSS-1H is Scheduled on Thursday, Aug 31, 2017 at 19:00 hrs from Satish Dhawan Space Centre, SHAR, Sriharikota

ЦитироватьAug 30, 2017

The 29 hrs countdown operations of PSLV-C39/IRNSS-1H mission have started on Wednesday, Aug 30, 2017 at 14:00hr IST

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Curtain Raiser Video of IRNSS-1H (English)

http://www.isro.gov.in/sites/default/files/videos/irnss-1h-english.mp4.mp4 (http://www.isro.gov.in/sites/default/files/videos/irnss-1h-english.mp4.mp4)
Description: Curtain Raiser Video of IRNSS-1H (English)
 Format : MP4
 File Size : (75.24 MB)
 Duration : 00:08:50
 Plugin : NA

ЦитироватьAug 30, 2017

Propellant filling operations of fourth stage (PS4) of PSLV-C39 are under progress

ЦитироватьIndia's PSLV set for IRNSS Navigation Satellite Replacement Launch to Mitigate Clock Issues
 August 30, 2017 (http://spaceflight101.com/pslv-c39/pslv-set-for-irnss-replacement-launch/)

The Indian Space Research Organization is counting down to the launch of a Polar Satellite Launch Vehicle on Thursday with a revamped IRNSS navigation satellite set to provide critical replacement capacity to begin dealing with a systemic clock issue that is affecting India's first IRNSS generation.

Liftoff fr om the Satish Dhawan Space Center is planned at 13:30 UTC and the four-stage PSLV will be in action for 19.5 minutes to deliver the IRNSS-1H satellite into a sub-GTO orbit fr om where it will maneuver up into an inclined Geosynchronous Orbit to replace the constellation's first satellite that has lost all its onboard clocks due to short circuits.

Спойлер

(https://img.novosti-kosmonavtiki.ru/153472.jpg) (https://img.novosti-kosmonavtiki.ru/153472.jpg)
Photo: Indian Space Research Organization

The Indian Regional Navigation Satellite System (IRNSS) was inaugurated in July 2013 when its first satellite was sent into orbit to begin establishing a seven-satellite constellation in Geostationary and inclined Geosynchronous Orbits to deliver coverage to the Indian Subcontinent and surrounding regions. Independent access to navigation was seen as a priority to eliminate India's reliance on outside systems such as GPS that may not be available in times of distress.

With initial concepts drawn up in 2006, IRNSS was designed to be multi-level redundant: on the individual satellite level, each member of the constellation carries three atomic timekeepers in a two-redundant architecture and the constellation level was laid out to operate seven satellites at any time, allowing one to fail without affecting the operation of the system. Additionally, two spare satellites were built to remain in a flight-ready configuration to be available for launch on short notice.

(https://img.novosti-kosmonavtiki.ru/153466.jpg) (http://spaceflight101.com/pslv-c39/wp-content/uploads/sites/176/2017/08/irnssconst.jpg)
IRNSS Constellation – Image: ISRO

IRNSS reached its initial operational capability in early 2016 with five satellites in operation and the final two followed by July of last year, allowing IRNSS to head into its fully operational phase. However, beginning in mid-2016, IRNSS-1A – the oldest of the constellation – experienced failures of its onboard rubidium atomic clocks, eventually losing all three time keepers, putting the satellite into a severely degraded state as it could only output coarse signals that were not useful for precise navigation.

The IRNSS constellation uses the same rubidium atomic frequency standard clocks as the European Galileo (http://spaceflight101.com/spacecraft/galileo/) positioning, navigation and timing system and China's Beidou (http://spaceflight101.com/spacecraft/beidou-3/) navigation architecture. Reports emerged in January that clocks on the Galileo constellation were failing at an alarming rate with both types of clocks on the satellites being affected – the robust rubidium clocks and the more precise Hydrogen Masers.

>> IRNSS Satellite & Constellation Overview (http://spaceflight101.com/spacecraft/irnss/)

(https://img.novosti-kosmonavtiki.ru/153463.jpg) (http://spaceflight101.com/pslv-c39/wp-content/uploads/sites/176/2017/08/9irnss-1hincleanroomatsdscshar12.jpg)
Photo: ISRO

All clocks on Galileo, IRNSS and China's Beidou-2 constellation were manufactured by Swiss company Spectratime, but the Beidou clocks were built before a defective component was introduced into the subsequent production series, sparing the Chinese fr om clock troubles on their constellation. The early Galileo In-Orbit Validation Satellites have also shown stable operation of their rubidium clocks which were built to the previous production specification.

An investigation into the problem isolated the in-orbit failures to a short circuit in an inexpensive electronics component used on the rubidium clocks while the problems on Galileo's Hydrogen Masers were traced to a separate issue related to how the masers are switched on and off, implementing procedural changes to work around the problem.

A comparison between failure signatures showed the clocks on Galileo and IRNSS-1A failed in the exact same fashion, building further confidence in the fault tree analysis and repair procedure worked out for existing rubidium clocks. As a result, clocks already installed on Galileo satellites awaiting launch and IRNSS ground spares were removed and shipped back to undergo repairs and re-tests.

To extend the operational lives of the satellites already in orbit, ISRO changed the procedure of how the three clocks are run. Initially, two of the clocks were kept running with one in primary mode and one as a hot backup while the third was powered off. As a life extension measure, ISRO decided to have only one clock running and two powered off, only activating the backup clocks when the primary one encounters a problem.

(https://img.novosti-kosmonavtiki.ru/153461.jpg) (http://spaceflight101.com/pslv-c39/wp-content/uploads/sites/176/2017/08/4irnss-1hisundergoingilluminationtest.jpg)
IRNSS-1H during final testing – Photo: IRNSS

Reports emerged in June that up to four clocks in addition to those on IRNSS-1A have suffered problems, but ISRO did not confirm these press reports.

Work has already been underway within ISRO's Satellite Applications Center to develop rubidium clocks for the next generation of IRNSS satellites set to take over from the first generation in the mid-2020s and ISRO also signed an agreement with Israel regarding cooperation in development of spaceborne atomic clocks, likely in an effort to implement clocks from two vendors on the next satellite generation to eliminate the risk of a single systemic issue causing a constellation-wide interruption.

The IRNSS-1H satellite is identical to the other first generation IRNSS satellites but implements repaired rubidium clocks featuring the same fix as those being currently integrated into a group of four Galileo satellites targeting liftoff in December. The IRNSS-1H satellite weighs 1,425 Kilograms and will be dispatched into a sub-GTO type orbit from wh ere it will maneuver into the western IGSO plane of the IRNSS constellation wh ere it will take over for the 1A satellite. ISRO is also expecting to launch the IRNSS-1I satellite before the year is out to place another operational spare into orbit to be able to quickly respond if another satellite loses all of its atomic clocks.

(https://img.novosti-kosmonavtiki.ru/153464.jpg) (https://img.novosti-kosmonavtiki.ru/153464.jpg)
Photo: ISRO

Thursday's launch will be the 41st flight of India's PSLV rocket that handled all seven previous IRNSS missions, leveraging the raw power of solid rocket motors in combination with the precision of liquid-fueled engines to accurately inject payloads into a variety of orbits.

When flying in its XL configuration, PSLV weighs in at 321 metric tons and employs a stack of four stages plus six strap-on solid rocket boosters. PSLV sports a 20.3-meter long first stage holding 138 metric tons of solid propellant with six extended Solid Rocket Boosters clustered around it, each holding another 13 tons of propellant to deliver the kick needed to send the vehicle on its way with a maximum thrust of over 800 metric-ton-force.

The 12.8-meter second stage is outfitted with a 799kN Vikas engine consuming 40,700kg of toxic hypergolic propellants while the third stage burns 6,700kg of solid fuel to accelerate the stack onto a sub-orbital arc. In charge of finishing the boost to orbit is the fourth stage, powered by a pair of low-thrust engines using a hypergolic propellant combination.

>> PSLV Launch Vehicle (http://spaceflight101.com/spacerockets/pslv/)

The PSLV rocket entered countdown operations on Wednesday, 29 hours prior to the planned liftoff time to undergo propellant loading operations to fill the fourth stage with two metric tons of propellants before proceeding with loading the second stage and the first stage's roll control system. Standing tall atop the Second Launch Pad at Satish Dhawan, PSLV C39 will be put through a last round of tests before pressing into the final countdown phase that includes flight software load on the vehicle and a 12-minute automatic sequence to ready the vehicle for flight.

Launch Profile

(https://img.novosti-kosmonavtiki.ru/153467.jpg) (http://spaceflight101.com/pslv-c39/wp-content/uploads/sites/176/2017/08/pslv-c34takeoff-view6.jpg)
Photo: ISRO (File)

When clocks hit zero, the PS1 stage will fire its ignition system followed by ignition commands issued to two pairs of Solid Rocket Boosters at T+0.42 and T+0.62 seconds, creating a total thrust of 700,600 Kilogram-force. Jumping off its launch pad, the 44.4-meter tall PSLV will climb vertically for a short moment before pitching over to start flying south-east across the Indian Ocean, aligning itself with its planned ascent trajectory headed for a sub-GTO type orbit.

>> Flight Profile (http://spaceflight101.com/pslv-c39/flight-profile/)

The remaining two Solid Rocket Boosters begin firing at T+25 seconds when PSLV will be 2.7 Kilometers in altitude, increasing the total thrust of the vehicle to 803 metric tons, further accelerating the launcher. Each of the boosters burns for 49.5 seconds, but to ensure a clean separation and off-shore impact, PSLV will hold the ground-lit boosters until T+1 minute and ten seconds when they will be separated in pairs, 0.2 seconds apart at an altitude of 24 Kilometers. The air-lit boosters will tail-off for separation one minute and 32 seconds into the flight.

The massive first stage will continue firing, delivering 496 metric tons of thrust as it burns through 138,000 Kilograms of solid propellant in just 105 seconds, lofting the vehicle to an altitude of 56 Kilometers and a speed of 2.4km/s. Separation of the first stage is expected one minute and 50 seconds into the flight with second stage ignition an instant later.

The Vikas 4 engine of the second stage will soar up to a thrust of 81,500 Kilogram-force for a burn of just over 2.5 minutes. Starting the second stage burn, the vehicle will transition from a pre-determined attitude profile flown during PS1 to Closed Loop Control to dynamically adjust its flight profile based on measured navigation data in order to meet its cutoff targets.

At T+3 minutes and 23 seconds, the vehicle will have reached an altitude of 115 Kilometers, making it safe to separate the protective payload fairing since aerodynamic forces no longer present a danger to the satellite at that altitude. The second stage will conclude its burn and separate at T+4:23, reaching an altitude of 135 Kilometers and a speed of 5.38km/s.

(https://img.novosti-kosmonavtiki.ru/153465.jpg) (http://spaceflight101.com/pslv-c39/wp-content/uploads/sites/176/2017/08/c39profile.jpg)
Image: ISRO

Third stage ignition occurs one second after staging, starting a burn of 113 seconds during which the stage will deliver 24,900 Kilogram-force of thrust. After burnout of the third stage, PSLV will keep holding onto the stage for the nominal Stage 3-4 coast phase that is designed to allow the stack to gain altitude ahead of the fourth stage burn. It also allows the third stage to tail off any residual thrust to ensure a safe separation. The coast lasts from T+6:17 to T+10:07, a period during which the stack climbs from 135 to 185 Kilometers.

Separation of the third stage is expected ten minutes and seven seconds into the flight followed ten seconds later by the ignition of the fourth stage's L-2-5 engines on a burn of eight minutes and 32 seconds. IRNSS-1H is targeting an insertion orbit of 284 by 20,650 Kilometers at an inclination of 19.2 degrees.

IRNSS-1H will be separated from the PSLV at T+19 minutes and 25 seconds at an altitude of 507 Kilometers and an insertion speed of 9.6km/s.

Very shortly after separation, the satellite will deploy its two power-generating solar arrays, establish communications with ground stations and stabilize its three-axis orientation. Over a period of days, the spacecraft will complete four burns of its Liquid Apogee Motor to ins ert itself in to a 29-degree inclined Geosynchronous Orbit at 55 degrees East longitude wh ere it can take over from IRNSS-1A.

[свернуть]

ЦитироватьLive Webcast of PSLV-C39/IRNSS-1H Mission Launch
 
(https://img.novosti-kosmonavtiki.ru/230436.png)

ЦитироватьAug 30, 2017

Propellant filling operations of fourth stage (PS4) of PSLV-C39 are completed

ЦитироватьAug 31, 2017

Propellant filling operations of second stage (PS2) of PSLV-C39 are under progress

Цитировать (https://img.novosti-kosmonavtiki.ru/186040.jpg) Chris B - NSF‏ @NASASpaceflight (https://twitter.com/NASASpaceflight) 3 ч. назад (https://twitter.com/NASASpaceflight/status/903062883042557952)

ARTICLE: Indian PSLV set for IRNSS replacement satellite launch - https://www.nasaspaceflight.com/2017/08/indian-pslv-irnss-replacement-launch/ ... (https://t.co/8ZGPEFmDCy) - by William Graham
(https://img.novosti-kosmonavtiki.ru/166635.jpg)

Спойлер

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[свернуть]

Цитировать

Indian PSLV set for IRNSS replacement satellite launch (https://www.nasaspaceflight.com/2017/08/indian-pslv-irnss-replacement-launch/)

ЦитироватьAug 31, 2017

Propellant filling operations of second stage (PS2) of PSLV-C39 are completed

ЦитироватьIndian rocket ready for launch to enlarge country's navigation satellite fleet
August 31, 2017 (https://spaceflightnow.com/2017/08/) Stephen Clark (https://spaceflightnow.com/author/stephen-clark/)

An Indian Polar Satellite Launch Vehicle is scheduled for liftoff Thursday with the eighth satellite for the country's regional navigation network, replacing a spacecraft launched four years ago with faulty payload components.

The PSLV is set for launch at 1330 GMT (9:30 a.m. EDT) Thursday from the Satish Dhawan Space Center on India's east coast. The 29-hour countdown began Wednesday, and filling of the rocket's liquid propellant tanks was underway in the final hours of the countdown.

Спойлер

(https://img.novosti-kosmonavtiki.ru/126756.jpg)
The PSLV's liquid-fueled second stage is lifted atop the rocket's first stage during preparations before the IRNSS 1H launch. Credit: ISRO

Liftoff is timed for 7 p.m. Indian Standard Time.

The 144-foot-tall (44-meter) PSLV will heave the eighth satellite in the Indian Regional Satellite System — IRNSS 1H — into an orbit stretching more than 12,800 miles (20,650 kilometers) above Earth.

IRNSS 1H will replace the first Indian navigation satellite in the IRNSS fleet — IRNSS 1A — stricken with failed atomic clocks, eliminating its ability to transmit precise position data to users on the ground. Designed for a 10-year mission, IRNSS 1A is otherwise healthy can still be used for basic message relay functions, according to the Indian Space Research Organization.

The three rubidium atomic clocks on the IRNSS 1A satellite have failed since its launch in July 2013, leaving the spacecraft powerless in achieving its primary mission. Sourced from a Swiss company, the clocks are needed to keep precise time on the satellite, a measure needed to help derive the exact location of a receiver on the ground.

The rubidium clocks come from the same vendor as several clocks that have failed on Europe's Galileo navigation satellites. Engineers say they have fixed the clocks on the IRNSS 1H spacecraft set for launch Thursday, and the launch of the next batch of four European Galileo navigation satellites was delayed from earlier this year until December to ensure their clocks will not succumb to the same problem.

Launching with six lengthened solid rocket boosters — a configuration ISRO calls the PSLV XL — India's workhorse launcher will head east from the Satish Dhawan Space Center over the Bay of Bengal following liftoff Thursday. The six boosters, each packed with 12 metric tons of pre-loaded solid propellant, will fire more than a minute. Four of the motors will ignite at liftoff, and the other pair will ignite at T+plus 25 seconds.

A core first stage solid-fueled motor will burn in unison with the six strap-on boosters. The PSLV's core and boosters will collectively generate 1.7 million pounds of thrust.

The first stage will drop away at T+plus 1 minute, 50 seconds, at an altitude of more than 180,000 feet (55 kilometers). A single hydrazine-fueled Vikas engine will ignite for a firing lasting two-and-a-half minutes, propelling the rocket to 11,000 mph (5 kilometers per second).

(https://img.novosti-kosmonavtiki.ru/126757.jpg)
The IRNSS 1H satellite. Credit: ISRO

The rocket's clamshell-like payload shroud will peel away during the second stage burn at T+plus 3 minutes, 23 seconds, once the launcher has climbed above the dense lower layers of the atmosphere.

A solid-fueled third stage motor will ignite at T+plus 4 minutes, 23 seconds, and burn nearly four minutes. The fourth stage, powered by two hydrazine-fueled thrusters producing around 3,400 pounds of thrust, will then take over at T+plus 10 minutes, 16 seconds, for a eight-and-a-half minute firing to inject the mission's navigation payload into an elliptical, oval-shaped orbit high above Earth.

The PSLV's flight computer will aim to release the IRNSS 1H satellite in an orbit between 176 miles (284 kilometers) and 12,831 miles (20,650 kilometers). The target orbit has an inclination of 19.2 degrees to the equator.

Deployment of the IRNSS 1H satellite is scheduled for T+plus 19 minutes, 25 seconds.

IRNSS 1H's on-board engine will circularize its orbit at an altitude of nearly 22,300 miles (35,800 kilometers) in the first few weeks after launch. The satellite's final operational geosynchronous orbit will be tilted 29 degrees to the equator, a perch that will oscillate north and south of the equator at 55 degrees east longitude.

In that orbit, IRNSS 1H will stay constantly in the sky over India. Like its predecessors, the IRNSS 1H satellite is built for a 10-year mission.

Unlike U.S., Russian, European and Chinese navigation fleets designed for global reach, India's navigation satellite constellation is intended to provide positioning services over the country's domestic territory and neighboring nations.

[свернуть]

ЦитироватьPirat5 пишет:
где ошибка?

Цитироватьtnt22 пишет: 
IRNSS 1H will replace the first Indian navigation satellite in the IRNSS fleet — IRNSS 1A — stricken with failed atomic clocks, eliminating its ability to transmit precise position data to users on the ground.

ЦитироватьAug 31, 2017

The countdown operations of PSLV-C39/IRNSS-1H mission are progressing normally

Цитировать (https://img.novosti-kosmonavtiki.ru/186040.jpg) Chris B - NSF‏ @NASASpaceflight (https://twitter.com/NASASpaceflight) 24 сек. назад (https://twitter.com/NASASpaceflight/status/903239685878763520)

LIVE Coverage: PSLV launch with IRNSS-1H - UPDATES: https://forum.nasaspaceflight.com/index.php?topic=42196.0 ... (https://t.co/zHAy83hO8V)
(https://img.novosti-kosmonavtiki.ru/166675.jpg)

Цитировать (https://img.novosti-kosmonavtiki.ru/185376.jpg) Spaceflight101 LIVE‏ @S101_Live (https://twitter.com/S101_Live) 24 сек. назад (https://twitter.com/S101_Live/status/903243474820063233)

L-20 Min: Ground and onboard ordnances are now being enabled for flight, final status checks are coming up for flight authorization. #PSLV (https://twitter.com/hashtag/PSLV?src=hash)

ЦитироватьAug 31, 2017

Mission Director has authorised Vehicle Director for launch. Automatic Launch Sequence (ALS) program initiation authorised by Vechicle Director and ALS started for launch of PSLV-C39/IRNSS-1H Satellite mission at 18:47 hr IST

Цитировать (https://img.novosti-kosmonavtiki.ru/185376.jpg) Spaceflight101 LIVE‏ @S101_Live (https://twitter.com/S101_Live) 1 мин. назад (https://twitter.com/S101_Live/status/903245004159758336)

LAUNCH AUTHORIZATION GIVEN - #PSLV (https://twitter.com/hashtag/PSLV?src=hash), #IRNSS1H (https://twitter.com/hashtag/IRNSS1H?src=hash) & all ground support systems are ready for an on-time liftoff. http://cdn.24fd.com/events/isro/310817/pslv-c39/index.html ... (https://t.co/oL3Uhgag3C)


2 мин. назад (https://twitter.com/S101_Live/status/903244750664466435)

#IRNSS1H (https://twitter.com/hashtag/IRNSS1H?src=hash) spacecraft team confirms the satellite is configured for launch.

Цитировать (https://img.novosti-kosmonavtiki.ru/185376.jpg) Spaceflight101 LIVE‏ @S101_Live (https://twitter.com/S101_Live) 3 мин. назад (https://twitter.com/S101_Live/status/903245644529315842)

T-12 Minutes: #PSLV (https://twitter.com/hashtag/PSLV?src=hash)'s automatic launch sequencer has kicked in to take the vehicle through pressurization, transfer to internal & arming.

Цитировать (https://img.novosti-kosmonavtiki.ru/185376.jpg) Spaceflight101 LIVE‏ @S101_Live (https://twitter.com/S101_Live) 44 сек. назад (https://twitter.com/S101_Live/status/903246387877478401)

T-9 Minutes: The Secondary Injection TVC System on the 1st stage is setting up; it provides pitch & yaw control during flight. #PSLV (https://twitter.com/hashtag/PSLV?src=hash)

Цитировать (https://img.novosti-kosmonavtiki.ru/185376.jpg) Spaceflight101 LIVE‏ @S101_Live (https://twitter.com/S101_Live) 52 сек. назад (https://twitter.com/S101_Live/status/903246651783077888)

T-8 Minutes: Tanks on the second stage of the #PSLV (https://twitter.com/hashtag/PSLV?src=hash) are now pressurizing for flight. Telemetry checks are in work, data recorders running.

Цитировать (https://img.novosti-kosmonavtiki.ru/185376.jpg) Spaceflight101 LIVE‏ @S101_Live (https://twitter.com/S101_Live) 23 сек. назад (https://twitter.com/S101_Live/status/903247508922617856)

Final Tracking Checks are complete. All ground stations reported readiness to track the vehicle & relay telemetry. #PSLV (https://twitter.com/hashtag/PSLV?src=hash)

Цитировать (https://img.novosti-kosmonavtiki.ru/185376.jpg) Spaceflight101 LIVE‏ @S101_Live (https://twitter.com/S101_Live) 58 сек. назад (https://twitter.com/S101_Live/status/903249784437432320)

SHUTDOWN & SEPARATION of the second Stage. Altitude: 135 Kilometers.

Цитировать (https://img.novosti-kosmonavtiki.ru/185376.jpg) Spaceflight101 LIVE‏ @S101_Live (https://twitter.com/S101_Live) 2 мин. назад (https://twitter.com/S101_Live/status/903249872492662784)

IGNITION of the third Stage confirmed! Burning 7 metric tons of solid propellant, PS3 delivers 25 metric-ton-force of thrust. #PSLV (https://twitter.com/hashtag/PSLV?src=hash)

Цитировать (https://img.novosti-kosmonavtiki.ru/185376.jpg) Spaceflight101 LIVE‏ @S101_Live (https://twitter.com/S101_Live) 47 сек. назад (https://twitter.com/S101_Live/status/903250492876353536)

There appears to be an underperformance in today's #PSLV (https://twitter.com/hashtag/PSLV?src=hash) mission.
(https://img.novosti-kosmonavtiki.ru/166654.jpg)

Цитировать (https://img.novosti-kosmonavtiki.ru/185376.jpg) Spaceflight101 LIVE‏ @S101_Live (https://twitter.com/S101_Live) 2 мин. назад (https://twitter.com/S101_Live/status/903251271796305920)

Fourth stage engine ignition confirmed, about a minute before the planned time. Appears to be an off-nominal flight. #PSLV (https://twitter.com/hashtag/PSLV?src=hash)
(https://img.novosti-kosmonavtiki.ru/166667.jpg)

Цитировать (https://img.novosti-kosmonavtiki.ru/186040.jpg) Chris B - NSF‏ @NASASpaceflight (https://twitter.com/NASASpaceflight) 49 сек. назад (https://twitter.com/NASASpaceflight/status/903251929022824449)

Hmmm, the overlaps seem off....
(https://img.novosti-kosmonavtiki.ru/166650.jpg)

Цитировать (https://img.novosti-kosmonavtiki.ru/185376.jpg) Spaceflight101 LIVE‏ @S101_Live (https://twitter.com/S101_Live) 1 мин. назад (https://twitter.com/S101_Live/status/903252271638642688)

#PSLV (https://twitter.com/hashtag/PSLV?src=hash) has achieved orbit. Remains to be seen if the vehicle can at least partially compensate for the shortfall.

Цитировать (https://img.novosti-kosmonavtiki.ru/185376.jpg) Spaceflight101 LIVE‏ @S101_Live (https://twitter.com/S101_Live) 43 сек. назад (https://twitter.com/S101_Live/status/903252634940960769)

Launch Controller taking a concerned look at a screen with what appears to be onboard camera footage inside the fairing. #PSLV (https://twitter.com/hashtag/PSLV?src=hash)
(https://img.novosti-kosmonavtiki.ru/166658.jpg)

Цитировать (https://img.novosti-kosmonavtiki.ru/186040.jpg) Chris B - NSF‏ @NASASpaceflight (https://twitter.com/NASASpaceflight) 52 сек. назад (https://twitter.com/NASASpaceflight/status/903252750460493825)

Sadly, this launch is looking like a failure. Let's see what the fourth stage can salvage....but this is not pretty:
(https://img.novosti-kosmonavtiki.ru/166665.jpg)

Цитировать (https://img.novosti-kosmonavtiki.ru/185376.jpg) Spaceflight101 LIVE‏ @S101_Live (https://twitter.com/S101_Live) 2 мин. назад (https://twitter.com/S101_Live/status/903253323578527744)

Spacecraft separation command has been issued. #PSLV (https://twitter.com/hashtag/PSLV?src=hash)
(https://img.novosti-kosmonavtiki.ru/166676.jpg)

Цитировать (https://img.novosti-kosmonavtiki.ru/186040.jpg) Chris B - NSF‏ @NASASpaceflight (https://twitter.com/NASASpaceflight) 2 мин. назад (https://twitter.com/NASASpaceflight/status/903253403182264321)

Looks like the fairing never separated either, which is absolutely a mission failure event.
(https://img.novosti-kosmonavtiki.ru/166677.jpg)

Цитировать (https://img.novosti-kosmonavtiki.ru/67516.jpg) Jonathan McDowell‏Подлинная учетная запись @planet4589 (https://twitter.com/planet4589) 3 мин. назад (https://twitter.com/planet4589/status/903253490696421376)

Orbit around 165 x 6554 km instead of 284 x 20650 km

Цитировать (https://img.novosti-kosmonavtiki.ru/185376.jpg) Spaceflight101 LIVE‏ @S101_Live (https://twitter.com/S101_Live) 1 мин. назад (https://twitter.com/S101_Live/status/903254211277750272)

Range Operations director confirms #PSLV (https://twitter.com/hashtag/PSLV?src=hash) failed to separate its payload fairing. Further analysis to be carried out. Launch Failure.

Цитировать (https://img.novosti-kosmonavtiki.ru/186040.jpg) Chris B - NSF‏ @NASASpaceflight (https://twitter.com/NASASpaceflight) 3 мин. назад (https://twitter.com/NASASpaceflight/status/903254073172008960)

It looks like the spacecraft command to sep, worked and it now bouncing around in its fairing prison, in the wrong orbit too. (https://img.novosti-kosmonavtiki.ru/125491.png)

Цитировать (https://img.novosti-kosmonavtiki.ru/186040.jpg) Chris B - NSF‏ @NASASpaceflight (https://twitter.com/NASASpaceflight) 42 сек. назад (https://twitter.com/NASASpaceflight/status/903255052609040385)

ISRO say the launch is a failure, standby for words and then pull a Sea Launch on us by cutting the webcast.
(https://img.novosti-kosmonavtiki.ru/166678.jpg)

Цитировать (https://img.novosti-kosmonavtiki.ru/67516.jpg) Jonathan McDowell‏Подлинная учетная запись @planet4589 (https://twitter.com/planet4589) 1 мин. назад (https://twitter.com/planet4589/status/903255571381575681)

So we expect a single object cataloged in orbit: the combined 4th stage/fairing/payload.

Цитировать (https://img.novosti-kosmonavtiki.ru/67516.jpg) Jonathan McDowell‏Подлинная учетная запись @planet4589 (https://twitter.com/planet4589) 56 сек. назад (https://twitter.com/planet4589/status/903255782120095744)

Meanwhile the PSLV C39 third stage is in a suborbital trajectory. Original target was splash in Pacific just west of Chile.

Цитировать (https://img.novosti-kosmonavtiki.ru/185376.jpg) Spaceflight101 LIVE‏ @S101_Live (https://twitter.com/S101_Live) 22 сек. назад (https://twitter.com/S101_Live/status/903256190100045826)

Tracking data expected later today will confirm whether the PS4-IRNSS-1H-Fairing stack remained intact or whether there are debris. #PSLV (https://twitter.com/hashtag/PSLV?src=hash)

ЦитироватьLive PSLV-C39/IRNSS-1H Launch -ISRO

(https://img.novosti-kosmonavtiki.ru/220757.jpg) (https://www.youtube.com/user/amlansarma) AmlanTalks (https://www.youtube.com/channel/UCMOmu4E-7YYYAuhFb-nnuaw)

ЦитироватьPSLV-C39 launching IRNSS-1H Navigation satellite - Indian Regional Navigation Satellite System

(https://img.novosti-kosmonavtiki.ru/220717.jpg) (https://www.youtube.com/channel/UCIpP507KxXYZ2woNC1nV0LQ)
PTI News Corporation (https://www.youtube.com/channel/UCIpP507KxXYZ2woNC1nV0LQ)

Цитировать (https://img.novosti-kosmonavtiki.ru/186040.jpg) Chris B - NSF‏ @NASASpaceflight (https://twitter.com/NASASpaceflight) 4 мин. назад (https://twitter.com/NASASpaceflight/status/903259034328977410)

FAILURE PSLV launch with IRNSS-1H FAILS: ARTICLE: https://www.nasaspaceflight.com/2017/08/indian-pslv-irnss-replacement-launch/ ... (https://t.co/8ZGPEFmDCy) - COVERAGE: https://forum.nasaspaceflight.com/index.php?topic=42196.0 ... (https://t.co/zHAy83hO8V)
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Спойлер

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[свернуть]

Цитировать

Indian PSLV launch with IRNSS replacement satellite suffers apparent failure (https://www.nasaspaceflight.com/2017/08/indian-pslv-irnss-replacement-launch/)

Цитировать (https://img.novosti-kosmonavtiki.ru/185299.jpg) ANI‏Подлинная учетная запись @ANI (https://twitter.com/ANI) 9 мин. назад (https://twitter.com/ANI/status/903259756801835010)

Satellite got separated internally but it is enclosed within heat shield, fourth stage: ISRO Chief AS Kiran Kumar on failed IRNSS-1H mission
(https://img.novosti-kosmonavtiki.ru/166680.jpg)

Цитировать (https://img.novosti-kosmonavtiki.ru/186040.jpg) Chris B - NSF‏ @NASASpaceflight (https://twitter.com/NASASpaceflight) 4 мин. назад (https://twitter.com/NASASpaceflight/status/903264982183399425)

These shots show what we believe was satellite seperating, as commanded, but it was imprisoned inside the failed fairing.
(https://img.novosti-kosmonavtiki.ru/166682.jpg)

Спойлер

(https://img.novosti-kosmonavtiki.ru/166683.jpg)
(https://img.novosti-kosmonavtiki.ru/166684.jpg)

[свернуть]

ЦитироватьAug 31, 2017

PSLV-C39/IRNSS-1H Mission Unsuccessful

ЦитироватьAug 31, 2017

PSLV-C39 Flight Carrying IRNSS-1H Navigation Satellite Unsuccessful

The forty first flight of India's Polar Satellite Launch Vehicle (PSLV-C39), conducted today (August 31, 2017) evening from Satish Dhawan Space Centre SHAR, Sriharikota, was unsuccessful. PSLV-C39 had a normal lift-off at 1900 hrs IST (7:00 pm) and all the flight events took place exactly as planned, except heat shield separation. This resulted in satellite separation occurring within the heat shield. The satellite is inside the heat shield resulting in the unsuccessful mission. Detailed analysis is under progress to identify the cause of the anomaly in the heat shield separation event.

ЦитироватьBREAKING NEWS | IRNSS-1H mission from Sriharikota was unsuccessful, says ISRO chairman | Press Meet

(https://img.novosti-kosmonavtiki.ru/220719.jpg) (https://www.youtube.com/user/thanthitv) Thanthi TV (https://www.youtube.com/channel/UC-JFyL0zDFOsPMpuWu39rPA)

Опубликовано: 31 авг. 2017 г.

ЦитироватьIndia's First Private Sector-Built Satellite Launch Unsuccessful, Says ISRO: 10 Facts

"The 41st mission of PSLV has been unsuccessful. The heat shield did not separate and the satellite remains enclosed within the heat shield," said ISRO chairman AS Kiran Kumar. The trouble began three minutes into the launch but the outcome was known only 19 minutes later. The failure is of the rocket and the satellite built by the private consortium remains untested, scientists said.
...

ЦитироватьTwo-Decade Success Streak Ends with PSLV Launch Failure on IRNSS-1H Mission
 August 31, 2017 (http://spaceflight101.com/pslv-c39/pslv-launch-failure-irnss-h/)

(https://img.novosti-kosmonavtiki.ru/153462.jpg) (https://img.novosti-kosmonavtiki.ru/153462.jpg)
File Image of India's PSLV Rocket taking off at Night – Photo: ISRO

A streak of 36 successful launches over a period of 18 years ended on Thursday when India's PSLV rocket suffered an in-flight failure that left its payload – a replacement satellite for the Indian Regional Navigation Satellite System – in a lower- than-planned orbit and possibly trapped underneath the rocket's payload fairing.

According to the Indian Space Research Organization, the fate of the PSLV was sealed three and a half minutes into its planned 19.5-minute mission when the protective payload fairing failed to separate from the ascending rocket. Dragging the dead weight of the fairing, the rocket did not have the energy needed to attain its planned orbit peaking 20,650 Kilometers in altitude and only reached a much lower orbit of 167 by 6,555 Kilometers.

Спойлер

An open question is whether the payload fairing remained intact around the IRNSS-1H satellite after it separated from the rocket's upper stage – creating a potentially dangerous configuration with a fully-fueled satellite bouncing around within the fairing. Tracking data expected later on Thursday will clarify if the fairing remained in place around the fourth stage.

(https://img.novosti-kosmonavtiki.ru/153471.jpg) (http://spaceflight101.com/pslv-c39/wp-content/uploads/sites/176/2017/08/pslvc39pic.jpg)
PSLV C39 Pre-Launch – Photo: Indian Space Research Organization

Thursday's launch marked the 41st flight carried out by the Polar Satellite Launch Vehicle that has become the undisputed workhorse of the Indian space program – supporting the country's Earth observation programs, sending up communications satellites and dispatching probes to the Moon and Mars, also becoming a player on the commercial launch market as a cost-effective alternative for small satellite operators. It marked the third failure encountered by PSLV following a mishap on its very first mission in 1993 and a partial failure on its first operational flight in 1997 that left the payload in a lower-than-planned orbit.

PSLV had raked up 36 consecutive successes since its C2 mission in 1999 and, in recent years, stepped up its launch pace to become a dependable workhorse, not only for India, but a number of international customers that placed satellites on the four-stage rocket.

Thursday's flight started with an on-time liftoff at 7 p.m. local time, 13:30 UTC from the Second Launch Pad at the Satish Dhawan Space Center on India's East Coast. Blasting off half an hour after sunset, PSLV raced into the night under the loud thunder of its massive solid-fueled core stage and four ground-lit boosters, catapulting the vehicle off its pad with a thrust of 700 metric-ton-force.

Powering away from the Indian coast toward the south east, PSLV ignited the two remaining boosters when passing 25 seconds into the mission to increase the vehicle's thrust to over 800 metric ton-force. The 44.4-meter tall rocket shed the four ground-lits at T+70 seconds followed by the twin air-lit boosters one minute and 32 seconds into the mission while the first stage continued to burn until T+110 seconds.

(https://img.novosti-kosmonavtiki.ru/153470.jpg) (http://spaceflight101.com/pslv-c39/wp-content/uploads/sites/176/2017/08/pslv-c39-7-1.jpg)
Actual Flight Events Timeline based on PSLV Telemetry (Fairing Separation not listed) – Image: ISRO / DD News

With the 20-meter long core stage dropping away, PSLV fired up the liquid-fueled Vikas 4 engine on the second stage, pushing the vehicle out of the atmosphere with a thrust of 81,500 Kilogram-force. Three minutes and 24 seconds into the mission, PSLV had reached an altitude of 115 Kilometers, making it safe to jettison the payload fairing that enshrouds the delicate satellite during atmospheric flight to protect it from aerodynamic forces which would easily rip it apart.

Fairing separation is completed as early as safely possible to shed no-longer-needed mass and thus increase the rocket's performance, having to push less weight into orbit. However, in Thursday's case, no verbal confirmation of fairing separation was provided in real time and telemetry displays showing flight event times based on sensor data from the rocket did not register the fairing separation.

The second stage handed over to the solid-fueled third stage four minutes and 24 seconds into the flight, firing up its rocket motor on a 112-second burn to accelerate the vehicle onto a sub-orbital arc. Plots displaying the rocket's velocity vs. time and altitude vs. time as it progressed toward orbit began showing a considerable underperformance as the third stage was burning – a result of the rocket carrying the additional 1,150 Kilograms of fairing mass that were not planned to be present at this stage of the flight.

(https://img.novosti-kosmonavtiki.ru/153468.jpg) (http://spaceflight101.com/pslv-c39/wp-content/uploads/sites/176/2017/08/pslv-c39-3.jpg)
Trajectory Displays shows a significant underperformance suffered by PSLV C39 – Image: ISRO / DD News

The third stage managed to accelerate the vehicle to a speed of 6.96 Kilometers per second whereas the planned PS3 cutoff speed was 7.28km/s, representing a shortfall of 320 meters per second. In an attempt to rectify the situation, PSLV's computers calculated a new flight profile for the fourth stage, firing up its twin L-2-5 engines eight minutes and 50 seconds into the flight, around one and a half minutes earlier than planned. The fourth stage was up and running for eight minutes and 48 seconds, consuming all available propellants in an effort to stretch the rocket's available energy.

Data displays showed PSLV achieved an orbit of 167.4 by 6,554.8 Kilometers, inclined 19.18 degrees – well short of the target 284 x 20,650-Kilometer orbit. Spacecraft separation was commanded 17 minutes and 56 seconds into the flight at which point loaded springs were to push the IRNSS-1H satellite away from the rocket's fourth stage.

(https://img.novosti-kosmonavtiki.ru/153469.jpg) (http://spaceflight101.com/pslv-c39/wp-content/uploads/sites/176/2017/08/pslv-c39-5.jpg)
A Launch Controller looks at onboard video from PSLV showing the Fairing still in place around the satellite – Photo: ISRO / DD News

What transpired at this point is uncertain – one scenario could be that the satellite separated and ended up bouncing around within the closed fairing, but there are also possibilities of the fairing giving way. The satellite was likely programmed to extend its power-generating solar arrays after a defined period of time following separation which could be another potentially harmful event with the fairing still in position. Tracking data expected later on Thursday will confirm whether the PS4-IRNSS-Fairing stack remained intact or whether debris are present.

Thursday's PSLV mission carried IRNSS-1H – the eighth satellite to launch as part of the Indian Regional Navigation Satellite System (IRNSS) and one of two ground spares built for the operational seven-satellite constellation called into service after clock failures on the IRNSS-1A satellite left the orbiting constellation without redundancy.

(https://img.novosti-kosmonavtiki.ru/153463.jpg) (http://spaceflight101.com/pslv-c39/wp-content/uploads/sites/176/2017/08/9irnss-1hincleanroomatsdscshar12.jpg)
Photo: ISRO

Initiated in 2006, the IRNSS project has the overall goal of establishing an independent navigation capability across India for government and civilian use, ending reliance on outside programs such as GPS which may be disabled in times of distress. Opting for a regional solution, India deployed seven IRNSS satellites between 2013 and 2016, three residing in Geostationary Orbit above the equator and four orbit in inclined Geosynchronous Orbits using two orbital planes to create a coverage area across the entire Indian territory and around 1,500 Kilometers beyond its borders.

The satellites are nearly identical, based on the Indian Space Research Organization's I-1K platform, each weighing in at around 1,425 Kilograms and hosting three rubidium atomic clocks that deliver the ultra-precise timing needed for the generation of navigation signals which are then transmitted to the ground in the L5 band and processed by compatible receivers to calculate a user's position via triangulation – requiring a sufficient number of satellites, typically four, to be visible at any given time.

IRNSS was designed with redundancy on the constellation and satellite levels – installing three clocks on each satellite to protect against isolated failures and operating the constellation in a one-redundant configuration. Additional insurance against a system outage came in the form of two ground spares, intended to be sent up in case any of the active satellites encountered problems to guarantee the first IRNSS generation can meet its planned ten-year life time.

(https://img.novosti-kosmonavtiki.ru/153466.jpg) (http://spaceflight101.com/pslv-c39/wp-content/uploads/sites/176/2017/08/irnssconst.jpg)
IRNSS Constellation – Image: ISRO

The problems aboard IRNSS-1A began in mid-2016 with the failure of one of its three atomic clocks with the other two following suit over the course of the second half of the year. This left the satellite severely disabled in its ability to deliver accurate navigation data. IRNSS-1A is still providing systems messages and coarse navigation signals but is not useful in precision applications.

The plot thickened in 2016 when the European Galileo constellation also noted an alarming failure rate on its clocks, affecting both types used on the European system – the more accurate Hydrogen Masers and the Rubidium Atomic Standard Clocks which are considered more robust. IRNSS, Galileo and China's Beidou-2 navigation systems all use clocks from the same supplier, Swiss company Spectratime, and analysis of the failures on IRNSS and Galileo showed the exact same mechanism that implicated an inexpensive electronics component causing short circuits within the clocks.

(https://img.novosti-kosmonavtiki.ru/153460.jpg) (http://spaceflight101.com/pslv-c39/wp-content/uploads/sites/176/2017/08/3irnss-1hatcleanroomwithoneofitssolarpanelsdeployed.jpg)
Photo: ISRO

The early Galileo In-Orbit Validation Satellites and the Beidou-2 system were not affected by the clock troubles as an earlier production series at Spectratime did not feature the component in question.

As a result of the inquiry into the clock troubles, existing clocks were removed from the two IRNSS spares and Galileo satellites waiting for launch to undergo repairs before being re-installed on their respective satellites. However, for the satellites already in orbit, there is no fix for the systemic clock issue – leaving 18 Galileo satellites and seven first generation IRNSS satellites at risk of complete rubidium clock failure.

To extend the operational lives of the satellites in orbit, ISRO decided to change the procedure of how the three clocks are operated. Initially, two clocks were kept in a powered state with one in primary mode and the other as a hot backup while the third was powered down. As a life extension measure, IRNSS satellites now only have one clock in a powered state, keeping the other powered off to preserve their useful lifetime for when they are needed.

To keep the constellation in a fully operational configuration, ISRO elected to call up the two ground spares for launch in 2017. IRNSS-1H was to maneuver into a 29-degree inclined Geosynchronous Orbit at 55 degrees East to replace the IRNSS-1A satellite launched in July 2013. This role will now be filled by the IRNSS-1I satellite that had been preparing for a November liftoff on a PSLV to join the constellation as additional backup in case of future clock troubles.

[свернуть]

Цитировать (https://img.novosti-kosmonavtiki.ru/185421.jpg) Spaceflight101‏ @Spaceflight101 (https://twitter.com/Spaceflight101) 2 ч. назад (https://twitter.com/Spaceflight101/status/903290853891944448)

#PSLV (https://twitter.com/hashtag/PSLV?src=hash) Stage 4/IRNSS-1H Satellite/Payload Fairing cataloged as 2017-051A in a 166 by 6,556-Kilometer orbit, inclined 19.16°.

ЦитироватьИндийский навигационный спутник вышел из строя при запуске
НЬЮ-ДЕЛИ, 31 августа. /ТАСС/. Отказ системы защиты от перегрева привел к гибели индийского навигационного спутника 1Н, выведенного в четверг на орбиту ракетой- носителем PSLV. Об этом сообщил глава Индийской организации космических исследований (ISRO) Киран Кумар.
"У нас произошла проблема, мы пытаемся разобраться в ситуации, проводится детальный анализ", - заявил он, признав, что, несмотря на успешный вывод навигационного спутника-дублера на заданную орбиту, миссия провалилась.
"Спутник находится на заданной орбите, но тепловая оболочка, предохраняющая аппарат от перегрева во время полета, не раскрылась", - уточнил Кумар.
Ранее Индийская организация космических исследований известила об успешном 41-ом запуске ракеты PSLV, произведенном в 19:02 (16:32 мск) с космодрома на острове Шрихарикота в Бенгальском заливе.

Спойлер

По замыслу индийских ученых, 1Н массой 1425 кг должен был подменить первый из семи уже работающих на орбите спутников навигационной системы - 1А, у которого вышли из строя трое рубидиевых атомных часов. Аналогичная проблема с атомными часами произошла недавно у европейской системы Galileo - сбои случились на половине спутников европейского созвездия.
Для постройки и тестирования 1H ISRO впервые привлекла консорциум из шести малых и средних частных индийских предприятий.

[свернуть]

Цитировать

31.08.2017 

Запуск индийского навигационного спутника признан неудачным (http://novosti-kosmonavtiki.ru/news/34585/)
... Запуск признан неудачным – не произошел сброс головного обтекателя. Хотя космический аппарат и удалось вывести на околоземную орбиту с параметрами 19,16 град. х 166 х 6556 км, использовать его по назначению не представляется возможным.

А.Ж.

Цитироватьzandr пишет:
"Спутник находится на заданной орбите, но тепловая оболочка, предохраняющая аппарат от перегрева во время полета, не раскрылась", - уточнил Кумар.

ЦитироватьISRO suspects pyro elements failed to separate rocket's heat shield

As a result of the heat shield not separating the 1,425 kg navigation satellite IRNSS-1H got stuck inside it resulting in the failure of the around Rs 250 crore mission.

By: IANS (http://indianexpress.com/agency/ians/) | Published:September 6, 2017 2:56 pm

(https://img.novosti-kosmonavtiki.ru/115320.jpg)
According to K. Sivan, Director, Vikram Sarabhai Space Centre (VSSC), all the systems during the rocket's flight worked well while the only suspect place is the pyro elements. (Image Source: PTI)

The Indian space agency is strongly suspecting the failure of pyro elements for the non-separation of the heat shield of its rocket Polar Satellite Launch Vehicle's (PSLV) XL variant on Aug 31, said a senior official. As a result of the heat shield not separating the 1,425 kg navigation satellite IRNSS-1H got stuck inside it resulting in the failure of the around Rs 250 crore mission.

Спойлер

Normally the heat shield will be separated soon after the rocket crosses the earth's atmosphere. According to K. Sivan, Director, Vikram Sarabhai Space Centre (VSSC), all the systems during the rocket's flight worked well while the only suspect place is the pyro elements.

The VSSC is part of the Indian Space Research Organisation (ISRO). "Tests are going on to find out the reasons for the failure of heat shield separation. Each test takes around 72 hours," Sivan told IANS.

One fortunate aspect of the failure is that ISRO has all the flight data as the rocket was not lost during its one way journey. Sivan said the heat shield would separate after on-board computers give the command to ignite the explosives. The explosives would then ignite and explode to separate the two parts of the heat shield joined by bolts.

[свернуть]

ЦитироватьThe Indian Space Research Organisation expects to resume launch of satellites in a couple of months once its failure analysis committee releases its report. The committee is conducting tests on why the PSLV-C39 mission of August 31 failed to release a back-up navigation satellite into space.

ISRO Chairman A.S. Kiran Kumar on Friday said the committee would release its report "very soon".

Спойлер

The launches would be resumed in November or December after necessary steps are taken. He was speaking on the sidelines of an event to mark 25 years of the formation of Antrix Corporation, which markets ISRO's products and services.

On the loss of IRNSS-1H in the launch, Mr. Kiran Kumar said the existing fleet of six spacecraft met all required specifications and there was no urgency for a replacement. "The overall performance of the [navigation] system is not affected," he said.

[свернуть]

ЦитироватьPyro devices to blame for PSLV failure: ISRO
 
Special Correspondent

Thiruvananthapuram, September 23, 2017 00:00 IST
Upd ated: September 23, 2017 04:57 IST

The Indian Space Research Organisation (ISRO) has come round to the inference that the PSLV C-39 mission on August 31 was doomed by the failure of the pyro devices that actuate the separation of the heat shield encasing the satellite from the rocket.

Спойлер

A high-level meeting chaired by ISRO chairman A.S.Kiran Kumar held at the VSSC here on Friday came to the conclusion on the failure of the pyro devices. The meeting was informed that simulation exercises were on to ascertain the reason for the malfunctioning of the pyro devices.

'Component isolated'

"We have isolated the component responsible for the failure of the mission but it remains to be established why it failed to function," VSSC Director Dr. K.Sivan said. "We are testing various versions and hope to arrive at a consensus in seven to 10 days". The exercises are expected to help the scientists analyse the failure from various angles.

ISRO had declared the PSLV- C39 mission unsuccessful after the heat shield refused to open and release the IRNSS-1H navigation satellite on board. The failure review committee se t up by ISRO had zeroed in on the electrically-operated pyro devices as the culprit after it was found that the command for separation had gone through but failed to trigger the mechanical process that pops open the heat shield.

Pyro devices use small charges to actuate the release mechanism that forces the fairings apart.

[свернуть]

ЦитироватьIsro to launch Cartosat 2 sat with 30 nano sats in mid-December

Surendra Singh (https://timesofindia.indiatimes.com/toireporter/author-Surendra-Singh-30991123.cms) | TNN | Updated: Oct 23, 2017, 05:26 IST

...
Dr Sivan said, "After the IRNSS-1H satellite failure, corrective measures will be taken in all rockets before the launches." Though the inquiry into reasons for the heat shield glitch is still going on, "initial findings suggested a defect in the pyro elements of the rocket which deal with the stage separation mechanism". The VSSC director said the committee probing the failure of IRNSS-1H launch will submit its investigation report much before the upcoming launches.

He said the faulty satellite stuck inside the heat shield is still orbiting the outer space and is "unlikely to fall into the Pacific Ocean anytime soon". On August 31, PSLV-C39 could not deliver the 1.4-tonne IRNSS-1H in the geo orbit as its heat shield did not get separated minutes after the rocket's lift-off from Sriharikota.

ЦитироватьMake in India: Joint venture of Isro and private firms to launch rocket by 2020
Chethan Kumar (https://timesofindia.indiatimes.com/toireporter/author-Chethan-Kumar-479220652.cms) | TNN | Updated: Oct 30, 2017, 19:22 IST

...
Inadequate pressure failed heat-shield separation

Isro chairman AS Kiran Kumar on Monday said that inadequate pressure in the bellow pump resulted in the heat shield not separating from the satellite, resulting in a failure of the mission on August 31.

The PSLV C-39 was carrying the IRNSS-1H was then declared an unsuccessful mission. The committee looking into the failure analysis, Kumar said, has found that the automated commands were performed accurately.

"There was no fundamental problem, that's clear. A system that has performed so well on so many occasion could not just go wrong. The failure happened because there was not enough pressure in the bellow pump, which resulted in the non-separation," Kumar said.

He said that a lot of external variables were responsible for this and the final report of the committee is awaited. Another senior official from Isro said that the simulations and other analysis by the committee is complete and that the report will soon be out.

Цитироватьtnt22 пишет:
The failure happened because there was not enough pressure in the bellow pump , which resulted in the non-separation," Kumar said.

ЦитироватьСтарый пишет:

В каком таком нижнем насосе?

ЦитироватьThe fairing is separated at an altitude of 115 Kilometers. Separation is accomplished by a linear piston cylinder separation and jettisoning mechanism (zip cord) running along the full length of the PLF and a clamp and joint at the base of the fairing. Both systems are pyrotechnically initiated. The gas pressure generated by the zip cord expands a rubber bellow that pushes that piston and cylinder apart, pushing the fairing halves laterally away from the launcher.

Цитироватьche wi пишет: 
Там же не "below" pump, а "bellow" pump.

ЦитироватьТам же не "below" pump, а "bellow" pump.

Цитировать(https://img.novosti-kosmonavtiki.ru/194830.gif) (http://timesofindia.indiatimes.com)
Isro cautious about December satellite launch
Nov 17, 2017, 06.44 PM IST

THIRUVANANTHAPURAM: After the recent failure of PSLV-C39 on August 31 this year, Isro centres here including VSSC and LPSC are doubly cautious. They are focused on the next mission of PSLV-C40 to launch 31 satellites including Cartosat -2ER by December end this year.
...

In the previous PSLV launch, there was no design fault. The heat-shield at the top nozzle of the rocket failed to release the satellite into orbit and it could be due to a fault in pyro-techniques, he said.

Normally the heat shield split into two halves at the conical nozzle opens up to release the satellite into the orbit, it failed to open 20 minutes after lift-off, the scientist explained. The heat shield is designed to absorb excessive heat produced by friction against atmosphere during take-off and to protect the components and fuel tanks of the rocket.

"The reason why it failed could be due to some hitch in the pyrotechnic material of the heat shield or probably failure of the springs to trigger the force against atmosphere to open the shield to eject the satellite out. The exact reasons are being ascertained by the 'Failure Analysis Committee of core scientists and the report will be released soon, said a lead scientist at VSSC.

...

While a VSSC scientist said, the failure analysis report is ready but it will be released only within the Isro centres. Based on its findings and recommendations all precautions will be taken to avert any failure, we are doubly cautious. A series of tests will be conducted before the next mission of PSLV-C40 slated for Dec end, he said.

...

Цитировать (https://img.novosti-kosmonavtiki.ru/185687.png) NewSpace India‏ @NewSpaceIndia (https://twitter.com/NewSpaceIndia) 6 мин. назад (https://twitter.com/NewSpaceIndia/status/975505815883866112)

Decay rate of IRNSS-1H/PS4 stack. http://dlvr.it/QLWfKx  (https://t.co/8alzE1VOkY)
(https://img.novosti-kosmonavtiki.ru/330655.png)

Цитировать(https://img.novosti-kosmonavtiki.ru/67516.jpg)Jonathan McDowell‏Подлинная учетная запись @planet4589 (https://twitter.com/planet4589) 2 ч. назад (https://twitter.com/planet4589/status/984260544264855552)

The IRNSS-1I navigation satellite launched today follows the failed launch of IRNSS-1H last year; it was left in a 6500 km apogee orbit which has now decayed to 4500 km
(https://img.novosti-kosmonavtiki.ru/162595.jpg)