IRNSS-1I – PSLV-C(?) XL – Шрихарикота – 2018 г.

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ISRO working on substitute navigation satellite

Work has begun in Bengaluru to assemble a substitute navigation spacecraft, which became essential after the main backup was lost in a failed launch on August 31, 2017.

IRNSS-1I was earlier approved as a ground spare, to be sent to space in an emergency. The Indian Space Research Organisation has been training a team fr om an industry consortium to assemble this spacecraft and its lost fellow satellite, IRNSS-1H.

Will there be another backup, an IRNSS-1J, and if so, who would assemble it? M. Annadurai, director of ISRO Satellite Centre (ISAC), Bengaluru, said the current approval is for seven navigation spacecraft (all of which are in orbit) and two spares — IRNSS-1H and IRNSS-1I. Should a new backup be sought and approved, it may be part of another model of outsourcing of its satellites to the Indian industry. ISRO has just begun the process of identifying a set of external partners who would assemble its future satellites, he noted. Until now all Indian spacecraft have been assembled at ISAC by its engineers.

Is the Assembly of 1I being advanced? Back in December, the consortium of six industries was given six months to work on each spacecraft. The deadline for IRNSS-1I was around May 2018. Dr. Annadurai said that as of now, the timeline was the same. The launch of 1I, when it was ready, would also have to align with ISRO's other missions, he said.

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ISRO awaits the report of the failure analysis committee, which is looking into reasons why the launch failed, before it returns to launch its next missions. The seven IRNSS spacecraft, from 1A to 1G, are part of the ₹1,400-crore GPS-like fleet for India, called NavIC (Navigation in Indian Constellation). They were put in orbit between July 2013 and April 2016 and have a life of 10 years each.

Soon after all of them were in place, all three atomic clocks in IRNSS-1A failed, warranting its replacement. IRNSS-1H was sent up on a PSLV rocket but was not released from the upper heat shield of the rocket. It has been falling slowly to Earth in the same state, embedded in the heat shield. Which is wh ere 1I enters — as a backup to both IRNSS-1A and IRNSS-1H.

The atomic clocks on the other satellites are being used sparingly to extend the clocks' life in space. ISRO chairman A.S. Kiran Kumar recently said there was no urgency as the remaining six are working as planned.

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https://spaceflightnow.com/launch-schedule/

April 12     PSLV • IRNSS 1I
Launch time: TBD
Launch site: Satish Dhawan Space Center, Sriharikota, India

India's Polar Satellite Launch Vehicle, flying on the PSLV-C41 mission, will launch the IRNSS 1I navigation satellite. The payload is the ninth spacecraft in the Indian Regional Navigation Satellite System, which aims to improve positioning services over India and neighboring regions. The PSLV will fly in the PSLV XL configuration with enlarged solid rocket boosters. Delayed from March. [March 23]

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Isro stays optimistic for IRNSS-1I launch up next

Bangalore Mirror Bureau | Updated: Apr 4, 2018, 04:00 IST
 Even as GSAT-6A stays mum,Isro readies satellite for April 12

Even as the Indian Space Research Organisation (Isro) is making efforts to reestablish link with the GSAT-6A satellite, the space agency has one more launch lined up for next week.

The launch of the IRNSS-1I navigation satellite is scheduled from the Satish Dhawan Space Centre in Sriharikota, tentatively slotted on April 12.

The IRNSS-1I Navigation Satellite has already reached the spaceport after it was transported from Bengaluru last month.

Though Isro officials have maintained that all future missions are on schedule despite the GSAT-6A setback, the launch of the IRNSS-1I is giving jitters to the space agency. To add to the nervousness, this will be the first time that the testing, assembling and integration have been entirely done by the private sector.

The IRNSS-1I is a replacement to a satellite whose launch was a failure.

The PSLV-C41, which will launch the IRNSS-1I, itself is a replacement for the IRNSS-1H which was declared a failure after the satellite separation occurred within the heat shield of the PSLV-C39 launched on August 31 last year. The committee looking into what led to failure of PSLV-C39 mission (the first involving a PSLV rocket in 24 years) concluded that inadequate pressure buildup in the bellow led to the failure of Isro's PSLV-C39.

Incidentally, the IRNSS-1H was to replace the IRNSS-1A, the first of the seven IRNSS satellites, launched in 2013.

Isro had hoped that with the launch of the IRNSS-1H the three atomic clocks of the IRNSS-1A which stopped working in 2016 would be
rectified.

Meanwhile more than three days after it lost contact with the GSAT-6A satellite, the space agency is still making efforts to establish the link with the satellite which snapped while the third orbit raising manoeuvre was to be fired on April 1

Запуск навигационного спутника IRNSS-1I запланирован с космодрома Сатиш-Дхаван в Шрихарикоте, предварительно намеченного на 12 апреля.

Навигационный Спутник IRNSS-1I уже достиг космодрома после его транспортировки из Бангалора в прошлом месяце.

Хотя должностные лица Исро утверждают, что все будущие полеты осуществляются по графику, несмотря на неудачу с ГСАТ-6А, запуск IRNSS-1I вызывает дрожь у космического агентства. Чтобы добавить нервозности, это будет первый раз, когда тестирование, сборка и интеграция были полностью сделаны частным сектором.