SRIHARIKOTA: India’s long cherished dream of owning an indigenous navigation satellite system, officially known as NavIC (navigation with Indian constellation), has been accomplished as ‘workhorse’ Polar Satellite Launch Vehicle (PSLV-C41) successfully launched IRNSS-1I, eighth and the last satellite of the IRNSS constellation into the targeted Sub-Geosynchronous Transfer Orbit on Thursday. Within a month from now, the space agency will start rolling out a slew of navigation applications.
In a pre-dawn operation, the rocket measuring 44.4 m in height and weighing 321 tonnes lifted off from the first launch pad at 4.04 am from the Satish Dhawan Space Centre (SDSC) SHAR, Sriharikota. Within 20 minutes, IRNSS-1I was placed in the desired orbit.
It is a culmination of 17 years of rigorous work by Indian space scientists. India took a firm decision on IRNSS in 1999 after the US government refused to share GPS data that would provide vital information on Pakistani troops position during Kargil war. As in the previous launches of the IRNSS satellites, PSLV-C41 has also used ‘XL’ version of PSLV equipped with six strap-ons, each carrying 12 tonnes of propellant.
IRNSS-1I is a back-up navigation satellite for IRNSS-1A. The Rs 1,420-crore NavIC suffered setback in January last year, when three rubidium atomic clocks of IRNSS-1A 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.
Soon after the success of the mission, ISRO Chairman K Sivan said, “PSLV-C41 precisely injected the eighth navigation satellite of India of the NavIC constellation into the targeted orbit. The entire ISRO community worked tirelessly to achieve this success. We have adopted a new technology called friction stir welding, which will improve the productivity and enhance the payload capability of the vehicle,” he said and added that the participation of the industry has been enhanced this time and space agency was slowly moving towards getting the entire satellite and the launch vehicle made from the industry.
ISRO Satellite Centre Director Mylswamy Annadurai said the solar arrays onboard IRNSS-1I have been successfully deployed and it would take about one month for the satellite to join its siblings after necessary orbit raising manoeuvres.
However, Sivan said the wait for NavIC applications was over. “Within a month from now, various NavIC application will be rolled out. I request the industry and institutions to come forward to take these (navigation) applications to the user community,” he said.
This holds significance in the backdrop of the Comptroller and Auditor-General’s adverse report, which was recently tabled in Parliament. The report criticised delays in NavIC saying an expenditure of Rs 1,283 crore had already been incurred on it,but the system was yet to be operationalised.
NavIC consists of three segments -- space, ground and user. The space segment comprises seven satellites in IRNSS series, while the ground segment is responsible for maintenance and operation of NavIC constellation.
The user segment comprises frequency user receivers capable of getting NavIC signals. “Though the space segment has been completed, NavIC remained non-operational due to non-completion of ground segment and user segment,” the report had said.
Further, ISRO officials said the crucial miniaturisation of chipsets that go into the wireless devices such as cell phones and wi-fi receivers has been achieved. Initially, the ISRO had invited industry to design and develop the chipsets.
However, little interest was shown due to high investment costs. “Market did not want to take the first step. So we took it on ourselves. Our Semiconductor Laboratory in Chandigarh has developed the digital chips and for manufacturing prototypes of RF Front End hardware, we gave the order to Tower Jazz, which is a US-based firm specialising in silicon germanium technology suited for increasing bandwidth. We are planning to set up a fabrication facility with silicon germanium processing technology in the SCL,” a senior scientist told Express.
Meanwhile, as reported by Express, the ISRO indicated that the phase two of IRNSS programme was on with advanced navigation satellites. Significantly, ISRO chief said the forthcoming navigation satellites will have rubidium atomic clocks developed by Ahmedabad-based Space Applications Centre, instead of imported clocks.
Missing GSAT-6A traced
Nearly a fortnight after ISRO lost communication satellite GSAT-6A, the space agency claimed on Thursday it has successfully tracked down the spacecraft and knows exactly its location and axis.Sivan told Express that after an exhaustive search involving multiple agencies across the globe, including the North American Aerospace Defence Command (NORAD), “We are able to track the satellite. The initial analysis suggests that the spacecraft is intact and rotating round the earth with a perigee (closest point to earth) of 26,000 km and apogee (farthest from earth) of 36,000 km,” he said.
To a query, Sivan said finding the satellite does not guarantee its recovery. “For some reason, we are still unable to establish communication. Our scientists are working round-the-clock. However, it is a big positive step that we know the spacecraft is in safe mode and intact,” he explained.GSAT-6A was launched on March 29 by GSLV-F08. The second orbit raising operation of the satellite has been successfully carried out on March 31. After the successful long duration firings, when the satellite was on course to normal operating configuration for the third and the final firing, scheduled for April 1, communication from the satellite was lost.
No fund crunch
ISRO chief has downplayed reports that the space agency was facing a fund crunch for its ongoing activities. “There is no fund crunch. We will ensure that the ongoing activities are not affected. What happened was the budgetary approval was based on previous year’s performance. We have to utilise the funds allotted fully, otherwise there will be a slight reduction. We can always propose a revised budgetary estimate. Getting funds is not a problem. It has been wrongly reported that the ISRO was facing funds crunch,” he clarified.
The total allocation for the Department of Space for next fiscal in the Union Budget for 2018-19 is around Rs 10,783 crore (including the Rs 8,936.97 crore for various space related projects), up from Rs 9,155.52 crore allocated for 2017-18 net of recoveries and receipts.
Nine launches in next eight months
Listing out the space mission for 2018, Sivan said the agency would launch 5.7-tonne GSAT-11, a high throughput satellite using Ariane rocket followed by GSAT 29 launch using GSLV Mk III rocket. There are also launch missions for remote sensing satellites and NavIC satellite onboard PSLV. The Chandrayaan-2/moon mission is planned by the year-end
RLV programme progressing steadily
Another ambitious programme Reusable Launch Vehicle (RLV) is progressing steadily. S Somanath, Director, Vikram Sarabhai Space Centre, said the next phase will be to test ground landing. ‘”In the previous RLV mission, we made simulated landing on the sea. Now, we will land on the wheels. It will be a helicopter drop test.
The next step will be to take it to an orbit, put in the orbit and do some useful tests and make a ground landing. The first step will be realised in the near future and the next one will be carried out after getting approval from the government. It is in engineering phase,” Somanath said.