INSAT-4B
{{Infobox spaceflight
| name = INSAT-4B
| image =
| image_caption =
| mission_type = Communications
| operator = INSAT
| COSPAR_ID = 2007-007A
| SATCAT = 30793
| mission_duration = Planned: 12 years
Duration: {{time interval|11 March 2007|24 January 2022|show=ymd|sep=,}}
| spacecraft_bus = I-3K
| manufacturer = ISRO
| launch_mass = {{convert|3028|kg|lb}}
| dry_mass = {{convert|1335|kg|lb}}
| power = 5,859 W{{cite web |url=https://www.isro.gov.in/Spacecraft/insat-4b |title=INSAT-4B |work=ISRO |date=7 February 2022 |access-date=7 February 2022 |archive-date=7 February 2022 |archive-url=https://web.archive.org/web/20220207174933/https://www.isro.gov.in/Spacecraft/insat-4b |url-status=dead }}
| launch_date = {{start-date|11 March 2007, 22:03|timezone=yes}} UTC{{cite web|url=http://planet4589.org/space/log/launchlog.txt|title=Launch Log|first=Jonathan|last=McDowell|work=Jonathan's Space Page|access-date=12 November 2013}}
| launch_rocket = Ariane 5ECA
| launch_contractor = Arianespace
| entered_service =
| disposal_type = Graveyard orbit
| deactivated = {{end-date|24 January 2022}}
| orbit_epoch = 11 November 2013, 22:16:22 UTC{{cite web|url=http://www.n2yo.com/satellite/?s=30793|title=INSAT 4B Satellite details 2007-007A NORAD 30793|work=N2YO|date=11 November 2013|access-date=12 November 2013}}
| orbit_reference = Geocentric
| orbit_regime = Geostationary
| orbit_periapsis = {{convert|35776|km|mi}}
| orbit_apoapsis = {{convert|35809|km|mi}}
| orbit_inclination = 0.07 degrees
| orbit_semimajor = {{convert|42163.57|km|mi}}
| orbit_eccentricity = 0.0003909
| orbit_period = 23.93 hours
| orbit_longitude = 85.5° E (relocated on 20 Feb 2020)
83° E (relocated on 12 Oct 2019)
111.2° E (relocated on 18 Dec 2017)
93.48° E (till 11 Nov 2017)
| apsis = gee
}}
INSAT-4B was an Indian communications satellite which forms part of the Indian National Satellite System. Launched in 2007, it was placed in geostationary orbit at a longitude of 93.48° East.{{cite web|url=http://www.ucsusa.org/assets/documents/nwgs/UCS_Satellite_Database_9-1-13.txt|title=UCS Satellite Database|publisher=Union of Concerned Scientists|date=1 September 2013|access-date=12 November 2013|archive-date=4 January 2014|archive-url=https://web.archive.org/web/20140104234546/http://www.ucsusa.org/assets/documents/nwgs/UCS_Satellite_Database_9-1-13.txt|url-status=dead}}
Built by the Indian Space Research Organisation, INSAT-4B is based upon the I-3K satellite bus. It had a mass at launch of {{convert|3028|kg}}, with a dry mass of {{convert|1335|kg}} and was expected to operate for twelve years. Two solar arrays power the satellite, while its communications payload consists of twelve C and twelve {{Ku band}} transponders.{{cite web|url=http://space.skyrocket.de/doc_sdat/insat-4a.htm|title=Insat 4A, 4B|first=Gunter|last=Krebs|work=Gunter's Space Page|access-date=12 November 2013}}
Arianespace was contracted to launch INSAT-4B using an Ariane 5 ECA carrier rocket. The launch occurred on 11 March 2007 at 22:03 UTC, from ELA-3 at Kourou. The Skynet 5A military communications satellite for the British Ministry of Defence was launched aboard the same rocket.
INSAT-4B was successfully inserted into geosynchronous transfer orbit, from which it raised itself into geostationary orbit using a liquid-fuelled apogee motor. It received the International Designator 2007-007A and Satellite Catalog Number 30793.{{cite web|url=http://planet4589.org/space/log/satcat.txt|title=Satellite Catalog|first=Jonathan|last=McDowell|work=Jonathan's Space Page|access-date=12 November 2013}} As of 11 November 2013, it is in an orbit with a perigee of {{convert|35776|km|mi}}, an apogee of {{convert|35809|km|mi}}, inclination of 0.07 degrees and an orbital period of 23.93 hours.
Partial power failure
On 10 July 2010 INSAT-4B suffered a disruption in power supply from one of the two solar panels, rendering half of its transponder capacity useless. After review the cause of malfunction was found out to be electric arcing in slip ring of one of the solar panels.{{Cite book|title=My Odyssey: Memoirs of the Man behind the Mangalyaan Mission|last=Radhakrishnan|first=Koppillil|publisher=Penguin UK|year=2016|isbn=978-9385990380|pages=190}} Similar partial power supply failure also affected Eutelsat W2M now known as Afghansat 1 and caused delay in launch of GSAT-8 due to required design changes in relevant power systems of satellite bus.{{Cite news|url=http://www.hindustantimes.com/india/india-losing-satellites-due-to-failure-of-imported-components/story-G4G7RDgXxSkqxdNIicgYkL.html|title='India losing satellites due to failure of imported components'|date=2010-07-11|work=hindustantimes.com/|access-date=2017-12-19|language=en}}{{Cite web|url=https://cag.gov.in/uploads/download_audit_report/2014/Union_Compliance_Satellite_Capacity_DTH_Service_22_2014_chapter_2.pdf|title=Management of satellite capacity for DTH service by Department of Space (Report number 22 by Comptroller Auditor General)|date=2014|access-date=5 March 2023}}
Relocation
On 11 November 2017, INSAT-4B maneuvered to lower its altitude and drifted eastward to reach new slot at 111.2°E on 18 December 2017.{{Cite web|url=https://www.space-track.org/|title=Archived TLE data from Space-track.org|access-date=19 December 2017}}
On 20 August 2019,{{Cite web|url=https://www.satellite-calculations.com/Satellite/getpositionhistory.php?30793?archive/2019/August/2019_August_|title=Historical satellite position data for INSAT-4B for the month of August 2019 Jens T. Satre www.satellite-calculations.com|website=www.satellite-calculations.com|access-date=2019-10-12}} altitude of INSAT-4B was raised and it was relocated to new 83°E slot on 12 October 2019.{{Cite web|url=https://www.satellite-calculations.com/Satellite/getpositionhistory.php?30793?archive/2019/October/2019_October_|title=Historical satellite position data for INSAT-4B for the month of October 2019 Jens T. Satre www.satellite-calculations.com|website=www.satellite-calculations.com|access-date=2019-10-12}}
On 15 February 2020, altitude of INSAT-4B was lowered and it was relocated to new 85.5°E slot on 20 February 2020.{{Cite web|url=https://www.satellite-calculations.com/Satellite/getpositionhistory.php?30793?archive/2020/February/2020_February_|title=Historical satellite position data for INSAT-4B for the month of February 2020 Jens T. Satre www.satellite-calculations.com|website=www.satellite-calculations.com|access-date=2020-02-20}}{{Cite web|url=https://ultra.news/s-e/49603/who-will-get-isros-new-capacity-sun-dish-or-tata-sky|title=Who will get ISRO's new capacity- Sun, Dish or Tata Sky?|date=2020-02-08|website=Ultra News|language=en-US|access-date=2020-02-20|archive-date=2020-02-20|archive-url=https://web.archive.org/web/20200220220622/https://ultra.news/s-e/49603/who-will-get-isros-new-capacity-sun-dish-or-tata-sky|url-status=dead}}
Decommissioning
Towards the end of its life INSAT-4B was placed in Graveyard orbit under post mission disposal procedure and subsequently decommissioned on 24 January 2022, in accordance with the space debris mitigation guidelines recommended by UN and the Inter Agency Space Debris Coordination Committee (IADC).{{Cite web|title=Successful post mission disposal of INSAT-4B Satellite - ISRO|url=https://www.isro.gov.in/update/07-feb-2022/successful-post-mission-disposal-of-insat-4b-satellite|access-date=2022-02-07|website=www.isro.gov.in|archive-date=2022-02-07|archive-url=https://web.archive.org/web/20220207234350/https://www.isro.gov.in/update/07-feb-2022/successful-post-mission-disposal-of-insat-4b-satellite|url-status=dead}}
References
{{Portal|Spaceflight}}
{{reflist}}
{{INSAT Satellites}}
{{Indian spacecraft}}
{{Orbital launches in 2007}}