RISAT-1

RISAT-1 had a mass at liftoff of {{cvt|1858|kg}}, making it the heaviest Earth observation satellite to be launched by India, and the heaviest satellite to be launched using a Polar Satellite Launch Vehicle. It had the capability to take images of Earth during day and night, as well as in cloudy conditions.

The satellite is equipped with a 160 × 4 Mbit/s data handling system, 50 Newton-metre-second reaction wheels, and a phased array antenna with dual polarisation.{{cite news|url=http://pibmumbai.gov.in/scripts/detail.asp?releaseId=E2012PR3130|title=The importance of RISAT-1|access-date=26 February 2013|newspaper=Press Information Bureau, Mumbai|date=26 April 2012}}

The mission has an approximate cost of {{INRConvert|4.90|b}};the spacecraft itself cost {{INRConvert|3.79|b}} to develop, and a further {{INRConvert|1.11|b}} to launch.{{cite news|url=http://timesofindia.indiatimes.com/india/India-successfully-launches-first-microwave-radar-imaging-satellite-RISAT--I/articleshow/12877123.cms|title=India successfully launches first microwave radar imaging satellite RISAT–1|newspaper=The Times of India|date=26 April 2012}} The satellite had a design life of five years.

The satellite was used for natural resources management, primarily agriculture planning and forestry surveys, as well as to predict and prevent flooding. It was used for monitoring paddy plantations and yields in the kharif season and to assist India's food security planning. Pictures from RISAT-1 was used to estimate the number of hectares being farmed in India, to assess crop health and predict total yield. It was also used to identify wreckage from aircraft that crashed in forested areas. RISAT-1 was not designed as a surveillance satellite, given its reliance on the C-band.

Its synthetic-aperture radar (SAR-C) has a resolution of 3 m to 50 m. It also supports a spotlight mode for prolonged focus on a given geographical area at a resolution of 1 m. Most of the design and the installation of basic instrument subsystems for the satellite was conducted in 2010.{{cite web|url=http://www.isro.gov.in/rep2005/EOS.htm|title=Earth Observation System |publisher=ISRO|access-date=21 March 2009|archive-url=https://web.archive.org/web/20081010150300/http://www.isro.gov.in/rep2005/EOS.htm|archive-date=10 October 2008}}

RISAT-1 was launched at 00:17 UTC (05:47 IST) on 26 April 2012 by a Polar Satellite Launch Vehicle, flight number C19, flying in the XL configuration with extended length solid strap-on boosters. The launch, which was the third flight of the PSLV-XL configuration, took place from the First Launch Pad of the Satish Dhawan Space Centre in Sriharikota, Andhra Pradesh. The launch marked the twenty-first flight of the PSLV, and its nineteenth successful launch.{{cite news |url=http://www.thehindu.com/news/national/article3355368.ece|newspaper=The Hindu|location=Chennai, India|first=M. Dinesh|last=Varma|title=PSLV-C19 puts RISAT-1 in orbit|date=26 April 2012}}

After launch RISAT-1 was placed in 470 x 480 km orbit with near 97° inclination. In next two days, RISAT-1 raised its orbital altitude using on-board propulsion to place itself into its operational Sun-synchronous orbit of 536 km with 06:00 Local Time of Equator Crossing.{{cite web|url=https://www.isac.gov.in/earth-observation/html/risat-1.jsp|title=RISAT-1|website=isac.gov.in |access-date=2018-02-22}}{{cite web|url=https://www.isro.gov.in/update/28-apr-2012/radar-imaging-satellite-risat-1-successfully-placed-its-final-orbit|title=Radar Imaging Satellite (RISAT-1) successfully placed in its final orbit|publisher=ISRO|website=isro.gov.in|access-date=2018-02-22|archive-date=22 February 2018|archive-url=https://web.archive.org/web/20180222165106/https://www.isro.gov.in/update/28-apr-2012/radar-imaging-satellite-risat-1-successfully-placed-its-final-orbit|url-status=dead}} The satellite began its normal operations with a repetitive cycle of 25 days.

On 30 September 2016, Joint Space Operations Center identified a debris generating event near RISAT-1.{{cite web|url=https://twitter.com/JointSpaceOps/status/783812350860140544|title=Debris-causing event ID'd near RISAT-1 (#38248) on 30 September 2016}}{{cite web|url=https://orbitaldebris.jsc.nasa.gov/Quarterly-News/pdfs/ODQNv20i4.pdf|title=NASA Orbital Debris Quarterly News, Volume 20, Issue 4, October 2016}} {{PD-notice}} The event created 16 pieces out of which 15 decayed and one was catalogued on 6 October 2016 under NORAD ID: 41797 and COSPAR ID: 2012-017C and decayed on 12 October 2016. Cause of this event was not officially declared but could be related to power system of satellite.{{Cite news |last=Krishnan |first=Raghu |date=2018-05-09 |title=It will take 3 years for industry to absorb satellite tech: K Sivan, ISRO chairman |work=The Economic Times |url=https://economictimes.indiatimes.com/news/science/it-will-take-3-years-for-industry-to-absorb-satellite-tech-k-sivan-isro-chairman/articleshow/64088256.cms |access-date=2023-05-07 |issn=0013-0389 |quote=In GSAT-6A, there could be a power issue. A spark could have led to a short circuit. In the last three satellites — GSAT-6, RISAT and GSAT-6A — we have shifted to a higher-powered satellite bus. We saw there were similar problems in RISAT after it completed its life.}} A month later on 3 November 2016, RISAT-1 data was declared unavailable on ESA's Copernicus Space Component Data Access portal due to satellite outage. Satellite was experiencing anomalies but ISRO denied they were related to fragmentation event.{{cite news|url=https://www.deccanchronicle.com/science/science/280317/risat-1-satellite-is-functioning-normally-says-isro.html|title=Risat-1 satellite is functioning normally, says ISRO}}{{cite web|url=https://spacedata.copernicus.eu/web/cscda/news/archive/-/asset_publisher/MUXrdlTX10kW/content/risat-1-unavailability|title=RISAT-1 unavailability|publisher=ESA}}

On 26 July 2017, Department of Space released names of its operational satellites in a reply to a Parliamentary query and RISAT-1 was not included in the list.{{cite web |url=http://164.100.47.194/Loksabha/Questions/QResult15.aspx?qref=54824&lsno=16|title=Details of satellites being operated by the country at present|last1=MORESHWAR PATIL|first1=KAPIL|last2=PATIL DANVE |first2=RAOSAHEB|date=26 July 2017|access-date=22 February 2018|last3=Singh|first3=Jitendra}}{{cite web|url=http://164.100.47.190/loksabhaquestions/annex/12/AU1824.pdf|title=Details of satellites being operated by the country|date=26 July 2017|access-date=22 February 2018|archive-date=22 February 2018|archive-url=https://web.archive.org/web/20180222165155/http://164.100.47.190/loksabhaquestions/annex/12/AU1824.pdf|url-status=dead}} Later in Annual Report 2017–18 of Department of Space, RISAT-1 was declared non-operational.{{cite web |url=https://www.isro.gov.in/sites/default/files/article-files/node/9805/annualreport2017-18.pdf|title=Annual Report Department of Space 2017-18|website=isro.gov.in|publisher=Department of Space, Government of India|archive-url=https://web.archive.org/web/20180213093132/https://www.isro.gov.in/sites/default/files/article-files/node/9805/annualreport2017-18.pdf|archive-date=13 February 2018|access-date=22 February 2018|quote=Anomalies have been observed towards the end of 5 years mission life and satellite is no more operational.}}

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Category:Spacecraft launched in 2012

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Category:RISAT