Raumfahrt - Start von ISRO´s PSLV / IRNSS-1I Mission



Despite Gsat-6A jolt, Isro gears up for navigation sat launch on April 12


NEW DELHI: Despite snapping of the communication link with its recently launched communication satellite Gsat-6A, Isro is gearing up for the scheduled launch of its next navigation satellite IRNSS-1I on April 12.
Isro chairman Dr K Sivan told TOI that the "upcoming launches like of IRNSS-1I will not be affected because of the snapping of signal link with communication satellite Gsat-6A". While one team of Isro is busy with re-establishing the contact with Gsat-6A, the second team is busy in preparations for the launch of the navigation satellite, says a source in Isro.IRNSS-1I, which will be launched by PSLV-C41 rocket from Sriharikota on April 12, will replace faulty IRNSS-1A navigation satellite, whose three Rubidium atomic clocks (meant to measure precise location data) had stopped working two years ago. IRNSS-1I weighing 600kg (dry mass) and a life span of 10 years will become the eighth satellite to join the constellation of navigation satellites called NavIC (Navigation with Indian Constellation) or popularly known as IRNSS.The seven-satellite indigenous navigation system is a smaller version of the American GPS, which with 31 satellites has global reach. The 'desi' GPS 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.On August 31 last year, Isro tried to launch IRNSS-1H to replace faulty IRNSS-1A but the navigation satellite got stuck in the heat shield of the PSLV rocket during the launch. The satellite, still stuck in the heat shield and now declared space debris, is wandering in the near-earth orbit and will ultimately fall to the Earth.
On Gsat-6A, the space agency said efforts were on to resume communication with the satellite. Sources said there was no indication of any system malfunction or fluctuations during or after launch.



Update: 7.04.2018


ISRO gears up for PSLV mission next week


THIRUVANANTHAPURAM: For the Indian Space Research Organisation (ISRO), there’s simply no time to sit back and mope. ISRO is preparing for its next mission even as the space agency is yet to come out of the shock dealt by the March 29 GSAT-6A mission which went awry. The Polar Satellite Launch Vehicle C-41 (PSLV C-41) mission is slated to lift off from the Sriharikota spaceport on April 12. The PSLV C-41 mission will place in orbit the IRNSS-1I satellite, a replacement for the IRNSS-1A satellite, whose rubidium atomic clocks failed. Though ISRO had intended to replace it with the IRNSS-1H in August last year, that satellite failed to separate from the payload fairing of the PSLV C-39 rocket. 

IRNSS-1I is technically the ninth satellite in the constellation that makes up the Indian Regional Navigational Satellite System (IRNSS). What is significant is that the April 12 mission comes barely two weeks after the March 29 GSLV Mk-II mission which left the space agency in a tizzy after the payload - the GSAT-6A satellite - got ‘lost’ in space. ISRO is still trying to restore communication with the satellite. S Somanath, director, Vikram Sarabhai Space Centre (VSSC), ISRO’s lead agency for space vehicles, said the space agency expected the PSLV C-41 mission to be a smooth one. 

‘’We have not taken any additional precautions as the satellite is a different type. Moreover, we had conducted a successful PSLV mission, the PSLV C-40, in January this year,” Somanath said. For the C-41 mission also, ISRO will be employing an XL version of the PSLV, he said.

Quelle: The New Indian Express


Update: 11.04.2018


Navigation satellite IRNSS-1I to be launched on April 12


The Indian Space Research Organisation will on April 12 launch a navigation satellite, the eighth such satellite to be a part of a constellation, the space agency said on April 10.

The PSLV-C41/IRNSS-1I Mission is scheduled to be launched on at 4.04 a.m. IST on April 12. IRNSS-1I is expected to replace IRNSS-1A, the first of the seven navigation satellites, that was rendered ineffective after its three rubidium atomic clocks failed. The seven satellites are part of the NavIC navigation satellite constellation.

The launch will be ISRO’s second attempt at sending a replacement satellite. The previous mission of a PSLV carrying IRNSS-1H in August 2017 failed after the heat shield covering the satellite failed to separate.

“India’s Polar Satellite Launch Vehicle, in its forty-third flight (PSLV-C41) in XL configuration will launch IRNSS-1I Satellite from First Launch Pad (FLP) of SDSC (Satish Dhawan Space Centre), Sriharikota,” ISRO said. The IRNSS-1I mission will take place two weeks after the space agency launched GSAT-6A on board GSLV Mk-II. Though the rocket placed GSAT-6A in orbit, ISRO lost communication with the satellite.

Quelle: The Hindu


Update: 12.04.2018


Launch of Navigation satellite IRNSS-1I


























Quelle: ISRO


Update: 13.04.2018


IRNSS-1I up in space, completes first phase of Indian regional navigation constellation


Although 1I is the ninth to be launched in the NavIC navigation fleet, it counts as the eighth.

Navigation satellite IRNSS-1I was put in orbit by the Indian Space Research Organisation's (ISRO) PSLV-C41 rocket early on Thursday morning.

Eighth in the series, the 1425- kg satellite completes the first phase of the Indian regional navigation constellation, ISRO Chairman K. Sivan said.

The PSLV-C41 lifted off at 4.04 a.m., as planned, from the First Launch Pad of the Satish Dhawan Space Centre at Sriharikota in coastal Andhra Pradesh, and after a flight lasting about 19 minutes, the satellite separated from it.

The navigation satellites, dubbed India's own GPS (Global Positioning System), are meant for giving precise information of position, navigation and time of objects or people. They were built by a consortium of six Indian companies led by Alpha Design Technologies Ltd., Bengaluru.

They have a civilian and a restricted military/security application.

10-year job up there

Built for a 10-year job in space, 1I is expected to be ready for work in about a month after routine orbit manoeuvres and tests.

Now orbiting in a temporary sub-geosynchronous oval path about 281.5 km x 20,730 km from the Earth and inclined 19.2 degrees to the Equator, it will be gradually pushed in the coming days into a geosynchronous circular orbit 36,000 km away, at an inclination of 29° over 55° East longitude, ISRO said.

Although 1I is the ninth to be launched in the NavIC navigation fleet, it counts as the eighth, as the previous one, 1H, was lost in a faulty launch last August.

They were planned as backups but became necessary after the three imported rubidium atomic clocks on 1A failed while in orbit.

Both 1I and 1H extensively involved the consortium in the assembly, integration and testing in Bengaluru — an exercise that ISRO would replicate in coming missions, Dr. Sivan said.

Request to industry, institutions

"The NavIC constellation is going to create history and make innovative applications to the entire community in ocean-based services, especially for the underserved and unserved,” Dr. Sivan said in his post-launch address.

“Very recently we created a NavIC-based application that will be released soon. I request industry and institutions to take these applications to the user community.”

In a hint about the loss of the newest GSAT-6A communication satellite in March, he said ISRO engineers had braved setbacks and would continue to rise to new challenges.

ISRO teams returned to launch activities from home ground in record 14 days after sending up GSAT-6A on March 29. However the two missions used different launch pads.

Quelle: The Hindu







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