Ajay Kumar at 07:46, 2 September 2023

2023-09-02T07:46:21Z

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{{Short description|Indian Earth observation satellite}}
{{Use British English|date=May 2020}}
{{Use dmy dates|date=May 2020}}
{{Infobox spaceflight
| name = IRS-1A
| names_list = Indian Remote Sensing satellite-1A
| image =
| image_caption =
| image_size = 300px

| mission_type = [[Earth observation satellite|Earth observation]]
| operator = [[Indian Space Research Organization|ISRO]]
| COSPAR_ID = 1988-021A
| SATCAT = 18960
| website = https://www.isro.gov.in/
| mission_duration = 3 years (planned)<br/>4 years (achieved)

| spacecraft = IRS-1A
| spacecraft_type =
| spacecraft_bus = IRS-1
| manufacturer = [[Indian Space Research Organization]]
| launch_mass = {{cvt|975|kg}}
| dry_mass = {{cvt|895|kg}}
| dimensions = 1.56 m x 1.66 m x 1.10 m
| power = 600 [[watt]]s

| launch_date = 17 March 1988, 06:43:00 [[Coordinated Universal Time|UTC]]
| launch_rocket = [[Vostok-2M]] s/n L15000-79
| launch_site = [[Baikonur Cosmodrome]], [[Baikonur Cosmodrome Site 31|Site 31]]
| launch_contractor = [[Energia (corporation)|OKB-1]]

| entered_service = June 1988 <ref name="WMO"/>
| disposal_type =
| deactivated = 1 July 1992 <ref name="WMO"/>
| last_contact =

| orbit_reference = [[Geocentric orbit]]<ref name="Trajectory"/>
| orbit_regime = [[Sun-synchronous orbit]]
| orbit_periapsis = {{cvt|863|km}}
| orbit_apoapsis = {{cvt|917|km}}
| orbit_inclination = 99.01°
| orbit_period = 102.7 minutes
| apsis = gee

| instruments = Linear Imaging Self-Scanning Sensor-1 (LISS-1)<br/>Linear Imaging Self-Scanning Sensor-2 (LISS-2)

| programme = [[Earth observation satellite|Earth observation satellites series]]
| previous_mission =
| next_mission = [[IRS-1B]]
}}

'''IRS-1A''', Indian Remote Sensing satellite-1A, the first of the series of indigenous state-of-art [[remote sensing]] satellites, was successfully launched into a polar [[Sun-synchronous orbit]] on 17 March 1988 from the [[Soviet Union|Soviet]] Cosmodrome at [[Baikonur Cosmodrome|Baikonur]]. IRS-1A carries two sensors, LISS-1 and LISS-2, with resolutions of {{cvt|72|m}} and {{cvt|36|m}} respectively with a swath width of about {{cvt|140|km}} during each pass over the country. Undertaken by the [[Indian Space Research Organisation]] (ISRO). It was a part-operational, part-experimental mission to develop Indian expertise in satellite imagery.

== History ==
The availability of [[Landsat program|Landsat]] imagery created a lot of interest in the science community. The [[Hyderabad]] [[ground station]] started receiving Landsat data on a regular basis in 1978. The Landsat program with its design and potentials was certainly a great model and yardstick for the IRS programme. IRS-1A was the first [[Indian Remote Sensing Programme|remote sensing mission]] to provide [[Satellite imagery|imagery]] for various land-based applications, such as agriculture, forestry, geology, and hydrology.<ref name="Display">{{cite web |url=https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1988-021A|title=Display: IRS-1A 1988-021A|publisher=NASA|date=27 April 2021|access-date=12 May 2021}} {{PD-notice}}</ref> The mission's long-term objective was to develop indigenous remote sensing capability.<ref>{{cite web|url=http://idn.ceos.org/KeywordSearch/Supplementals.do?Portal=lsi&KeywordPath=Platforms&EntryId=IRS-1A&MetadataType=2|title=Indian Remote Sensing Satellite-1A|publisher=CEOS International Directory Network (IDN)|access-date=April 8, 2013|archive-date=3 March 2016|archive-url=https://web.archive.org/web/20160303235020/http://idn.ceos.org/KeywordSearch/Supplementals.do?Portal=lsi&KeywordPath=Platforms&EntryId=IRS-1A&MetadataType=2|url-status=dead}}</ref>

== Satellite description ==
The [[satellite bus]], measuring 1.56 m x 1.66 m x 1.10 metres, had the payload module attached on the top and a deployable [[Solar panels on spacecraft|solar panels]] stowed on either side. [[Spacecraft attitude control|Attitude control]] was provided by four-[[Reaction wheel|momentum wheels]], two [[Magnetic moment|magnetic torques]], and a thruster system. Together, they gave an estimated accuracy of better than ± 0.10° in all three axes.<ref name="Display"/>

== Instruments ==
IRS-1A carried two "Linear Imaging Self-Scanning Sensor", LISS-1 and LISS-2, with a [[spatial resolution]] of {{cvt|72|m}} and {{cvt|36|m}} respectively.<ref name="ESA">{{cite web
|url=https://directory.eoportal.org/web/eoportal/satellite-missions/i/irs|title=IRS-1A (Indian Remote Sensing Satellite-1A)|publisher=ESA Earth Observation Portal|access-date=12 May 2021}}</ref> The [[three-axis stabilisation|three-axis-stabilised]] Sun-synchronous satellite carried LISS sensors which performed "[[Push broom scanner|push-broom]]" scanning in [[Visible spectrum|visible]] and [[Infrared|near-infrared]] bands to acquire images of the [[Earth]]. Local equatorial crossing time (ECT) was fixed at around 10:30 of the morning.<ref name="Display"/>

== Launch ==
IRS-1A was launched on 17 March 1988, at 06:43:00 [[Coordinated Universal Time|UTC]]. It had a [[apsis|perigee]] of {{cvt|863|km}}, an [[apsis|apogee]] of {{cvt|917|km}}, an [[orbital inclination|inclination]] of 99.01°, and an [[orbital period]] of 102.7 minutes.<ref name="Trajectory">{{cite web|url=https://nssdc.gsfc.nasa.gov/nmc/spacecraft/displayTrajectory.action?id=1988-021A|title=Trajectory: IRS-1A 1988-021A |publisher=NASA|date=27 April 2021|access-date=12 May 2021}} {{PD-notice}}</ref>

== Mission ==
IRS-1A was operated in a [[Sun-synchronous orbit]]. IRS-1A successfully completed its mission on 1 July 1992 after operating for 4 years.<ref name="WMO">{{cite web|url=https://www.wmo-sat.info/oscar/satellites/view/irs_1a0|title=IRS-1A|publisher=World Meteorological Organization|date=28 July 2015|access-date=12 May 2021}}{{Dead link|date=August 2023 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>

== See also ==
{{Portal|Spaceflight}}
* [[Indian Remote Sensing]]

== References ==
{{Reflist|30em}}

== External links ==
* [https://web.archive.org/web/20101125194726/http://isro.org/satellites/irs-1a.aspx ISRO IRS-1A link]

{{IRS satellites}}
{{Indian spacecraft}}
{{Orbital launches in 1988}}

[[Category:Earth observation satellites of India]]
[[Category:Spacecraft launched in 1988]]
[[Category:1988 in India]]
[[Category:India–Soviet Union relations]]
[[Category:1988 in the Soviet Union]]

IRS-1A - Revision history

Ajay Kumar at 07:46, 2 September 2023