TKMD at 10:54, 2 April 2026

2026-04-02T10:54:50Z

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{{Short description|Indian radar imaging satellite}}
{{Use Indian English|date=May 2021}}
{{Use dmy dates|date=May 2021}}
{{Infobox spaceflight
| name = EOS-09
| names_list = Radar Imaging Satellite-1B
| image = EOS-9 during Integration.webp
| image_caption = EOS-9 during Integration
| image_size = 300px
| mission_type = [[Imaging radar]]
| operator = [[ISRO]]
| COSPAR_ID =
| SATCAT =
| website = {{url|https://www.isro.gov.in/Mission_PSLV_C61_EOS_09.html|ISRO PSLV-C61 / EOS-09 Mission}}
| mission_duration = 5 years (planned)<br/>Failed to orbit
| spacecraft = EOS-09
| spacecraft_type =
| spacecraft_bus =
| manufacturer = [[ISRO]]
| launch_mass =
| dry_mass = 
| dimensions = 
| power = 
| launch_date = 18 May 2025, 05:59 [[Indian Standard Time|IST]]
| launch_rocket = [[PSLV-C61]]
| launch_site = [[Satish Dhawan Space Centre]], [[Satish Dhawan Space Centre|First Launch Pad (FLP)]]
| launch_contractor = [[ISRO]]
| entered_service =
| disposal_type =
| deactivated =
| last_contact =
| orbit_reference = [[Geocentric orbit]]<ref name="ISRO-C52"/>
| orbit_regime = [[Sun-synchronous orbit]]
| orbit_periapsis = {{cvt|526.7|km}} (planned)
| orbit_apoapsis = {{cvt|543.4|km}} (planned)
| orbit_inclination = 97.6°
| orbit_period = 95.2 minutes
| apsis = gee
| instruments = [[Synthetic-aperture radar|Synthetic Aperture Radar]] ([[C band (IEEE)|C-band]]) (SAR-C)
| programme = '''[[Indian Remote Sensing Programme|EOS series]]'''
| previous_mission = [[EOS-08]]
| next_mission = [[EOS-N1]]
| programme2 = '''[[RISAT|RISAT Series]]'''
| previous_mission2 = [[EOS-04]]
| next_mission2 = [[RISAT-2A]]
}}

'''EOS-09''' or '''Earth Observation Satellite-09''' (formerly known as RISAT-1B) was an [[ISRO|Indian Space Research Organisation]] [[Imaging radar|radar imaging]] satellite designed to provide continuous and reliable remote sensing data for operational applications across various sectors.<ref>{{Cite web|title=EOS-09|url=https://www.isro.gov.in/Mission_PSLV_C61_EOS_09.html|work=[[ISRO]]|access-date=2025-05-18|archive-date=16 May 2025|archive-url=https://web.archive.org/web/20250516062456/https://www.isro.gov.in/Mission_PSLV_C61_EOS_09.html|url-status=live}}</ref> It was intended to be a follow on to [[RISAT-1]] satellite with similar configuration. The satellite was developed by the ISRO and was the seventh in the series of [[RISAT]] satellites.<ref>{{cite web |last=Krebs |first=Gunter |url=https://space.skyrocket.de/doc_sdat/risat-1.htm |title=RISAT 1, 1A, 1B (EOS 04) |work=Gunter's Space Page |date=8 October 2021 |access-date=26 December 2021 |archive-date=26 December 2021 |archive-url=https://web.archive.org/web/20211226005804/https://space.skyrocket.de/doc_sdat/risat-1.htm |url-status=live }}</ref><ref name="nic-20230329">{{cite web |url=https://pqals.nic.in/annex/1711/AU4702.pdf |title=Unstarred Question No. 4702 |work=[[Lok Sabha]] |publisher=[[National Informatics Centre]] |date=29 March 2023 |access-date=12 April 2023 |archive-date=29 March 2023 |archive-url=https://web.archive.org/web/20230329144006/https://pqals.nic.in/annex/1711/AU4702.pdf |url-status=dead}}</ref><ref>{{cite web |url=http://database.eohandbook.com/database/missionsummary.aspx?missionID=865 |title=Mission Summary - RISAT-1B |work=[[Committee on Earth Observation Satellites|CEOS]] |date=2021 |access-date=26 December 2021 |archive-date=26 December 2021 |archive-url=https://web.archive.org/web/20211226005804/http://database.eohandbook.com/database/missionsummary.aspx?missionID=865 |url-status=live}}</ref>

== Satellite description ==
[[Synthetic-aperture radar|Synthetic Aperture Radar (SAR)]] can be used for [[Earth observation satellite|Earth observation]] irrespective of the light and weather conditions of the area being imaged.<ref name="hindu-risat1radar">{{cite news |url=http://www.thehindu.com/sci-tech/technology/article3350204.ece|title=RISAT-1's radar can see through clouds and work in darkness|newspaper=The Hindu|date=25 April 2012|location=Chennai, India|first=N. Gopal|last=Raj}}</ref> It complements/supplements data from [[Resourcesat-2|Resourcesat]], [[Cartosat]] and [[RISAT-2B]] Series.<ref name=":0">{{Cite web|title=PSLV-C52/EOS-04 Brochure - ISRO|url=https://www.isro.gov.in/pslv-c52-eos-04-mission/pslv-c52-eos-04-brochure|access-date=2022-02-17|website=www.isro.gov.in|archive-date=9 February 2022|archive-url=https://web.archive.org/web/20220209140030/https://www.isro.gov.in/pslv-c52-eos-04-mission/pslv-c52-eos-04-brochure|url-status=dead}}</ref> The satellite carries a [[C band (IEEE)|C-band]] synthetic-aperture radar (SAR) and has a liftoff mass of {{cvt|1710|kg}}.<ref name="ISRO-C52">{{cite web|url=https://www.isro.gov.in/launcher/pslv-c52-eos-04-mission|title=PSLV-C52/EOS-04 Mission|access-date=9 February 2022|publisher=ISRO|archive-date=9 February 2022|archive-url=https://web.archive.org/web/20220209012447/https://www.isro.gov.in/launcher/pslv-c52-eos-04-mission|url-status=dead}}</ref> The EOS-09 orbit is expected to be in a polar and [[Sun-synchronous orbit]] (SSO) at 05:30 AM LTDN, at approximate altitude of 529 km.<ref name="UIM2016">{{cite web|last=Reddy|first=O.V. Raghav|date=3 February 2016|title=Future Earth Observation Missions of ISRO, NRSC User Interaction Meet 2016|url=http://nrsc.gov.in/sites/all/pdf/modnrscUIM%20_Raghava%20Reddy_1.pdf|url-status=dead|archive-url=https://web.archive.org/web/20170203144958/http://nrsc.gov.in/sites/all/pdf/modnrscUIM%20_Raghava%20Reddy_1.pdf|archive-date=3 February 2017}}</ref>

== Launch Failure ==
The [[PSLV-C61]] mission launched EOS-9 on 18 May 2025 at 5:59 AM IST. The first and second stages performed nominally, however, the third stage experienced an anomaly which resulted in loss of mission. ISRO is investigating the failure.<ref>{{Cite web |title=EOS-09 mission unsuccessful, will begin technical analysis, says ISRO chief - The Economic Times |url=https://m.economictimes.com/news/science/isro-launches-eos-09-aboard-pslv-c61-boosting-indias-surveillance-and-remote-sensing-powers/articleshow/121243650.cms |access-date=2025-05-18 |website=m.economictimes.com}}</ref><ref>{{Cite AV media |url=https://www.youtube.com/watch?v=y63x4kjvAc0&ved=2ahUKEwjpgp_T-qqNAxUo1TgGHXjQAn4QwqsBegQIERAE&usg=AOvVaw3pJjTU4LNboN-XF9jIVe1l |title=ISRO's 101st Launch {{!}} PSLV-C61 / EOS-09 {{!}} 18 May 2025 |date=2025-05-17 |last=ISRO Official |access-date=2025-05-18 |via=YouTube}}</ref>

== See also ==
{{Portal|Spaceflight}}
* [[PSLV-C61]]
* [[List of Indian satellites]]
* [[ISRO]]
* [[RISAT]]
* [[PSLV]]

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

{{PSLV}}
{{RISAT satellites}}
{{Indian spacecraft}}
{{Rest of the World Reconnaissance Satellites}}
{{Orbital launches in 2025}}

[[Category:Earth observation satellites of India]]
[[Category:Space synthetic aperture radar]]
[[Category:Spacecraft launched by India in 2025]]
[[Category:RISAT]]
[[Category:Space accidents and incidents in India]]

{{India-spacecraft-stub}}

EOS-09 - Revision history

TKMD at 10:54, 2 April 2026