PSLV-C61

The PSLV C-61 was the 63rd flight of the Indian Space Research Organisation's Polar Satellite launch Vehicle and its 27th flight in the -XL configuration.The Mission launched on 18th May 2025 carrying EOS-09 (RISAT 1-B). ^{[1] [2]}

PSLV-C61

PSLV-XL launch
Launch	18 May 2025 ;5:59 AM IST (UTC +5:30)
Operator	Indian Space Research Organisation (ISRO)
Pad	Satish Dhawan Space Centre First Launch Pad
Payload	India EOS-09 (RISAT-1B)
Outcome	Failure
PSLV launches
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Payload

Earth Observation Satellite-09 (EOS-09), also called RISAT 1-B was planned to be the seventh satellite in ISRO's RISAT series.It is a C-band synthetic aperture radar satellite, enabling it to capture high-resolution images of Earth’s surface regardless of weather conditions, day or night.The satellite features five distinct imaging modes, enabling it to switch between ultra-high-resolution imaging, capable of detecting small objects, and broader scans for large-area observation. The satellite was expected to boost India's space surveillance capabilities and contribute to smarter governance and faster disaster response.It was to be launched into a sun-synchronosis orbit (SSO) amidst tension on the India-Pakistan border. ^{[3] [4] [1] [5]} Orbit Change Thrusters (OCT) were planned to be used to reduce the orbit altitude of the spent PS4 stage to reduce its life in orbit following by stage passivation. ^[2]

Launch Failure

PSLV-C61 launched from SDSC-SHAR at 5:59 AM IST on Sunday 18th May 2025. The First and Second stages performed normally. A failure of the third stage led to mission failure. ^{[6] [7]} Later reports indicated that a drop in chamber pressure of the third stage during its firing led to failure. ISRO's failure analysis committee is expected to release the final failure report within a month. ^{[8] [9]} .

ISRO Chairman V.Narayanan reported to the media that the FAC commitee report has been finalised and submitted to the Prime Minister's Office. He announced the return to flight launch of the PSLV Rocket within three months. ^[10]

Mission overview

• Mass:
  • Payload weight: 1710 kg ^[4]
• Overall height: 44.4 m (146 ft) ^[2]
• Propellant:
  • Stage 1 (PS-1) : Composite Solid (Solid Stage)
  • Stage 2 (PS-2) : Earth Storable Liquid (Liquid Stage)
  • Stage 3 (PS-3): Composite Solid (Solid Stage)
  • Stage 4 (PS-4) : Earth Storable Liquid (Liquid Stage)
• Propellant mass:
  • Stage 1:139,000 kg (306,000 lb)
  • Stage 2:41,000 kg (90,000 lb)
  • Stage 3:7,650 kg (16,870 lb)
  • Stage 4:1,600 kg (3,500 lb)
• Altitude: 529 km ^[4]
• Maximum velocity:
• Inclination: 97.6° ^[2]
• Azimuth: 140° ^[2]
• Period: 95.2 minutes

See also

• EOS-09
• List of PSLV launches
• ISRO
• RISAT
• PSLV

References

1. "MSN". www.msn.com. Retrieved 14 May 2025.
2. https://www.isro.gov.in/media_isro/pdf/PSLVC61/PSLV_C61_EOS_09_Brochure.pdf
3. "Isro to launch radar imaging satellite RISAT-1B aboard PSLV-C61 on May 18". India Today. 8 May 2025. Retrieved 14 May 2025.
4. Nigam, Saumya (12 May 2025). "ISRO's new satellite launch scheduled for June 18 for Defence and Disaster Monitoring". India TV News. Retrieved 14 May 2025.
5. "MSN". www.msn.com. Retrieved 14 May 2025.
6. ISRO Official (17 May 2025). ISRO’s 101st Launch | PSLV-C61 / EOS-09 | 18 May 2025 . Retrieved 18 May 2025– via YouTube.
7. "EOS-09 mission unsuccessful, will begin technical analysis, says ISRO chief - The Economic Times". m.economictimes.com. Retrieved 18 May 2025.
8. "NDTV Explains: Why ISRO's EOS-9 Satellite Launch Failed". www.ndtv.com. Retrieved 19 May 2025.
9. Jagannathan, Venkatachari. "Consecutive ISRO Mission Failure Raises National Security Concerns". Rediff. Retrieved 19 May 2025.
10. Nair, Aparna (11 August 2025). "India's space station plans gain momentum; first module launch targeted for 2028: ISRO Chief". The New Indian Express. Retrieved 3 August 2025.