ISRO’s SSLV-D3 successfully launches EOS-08 Earth Observation Satellite

IN NEWS: ISRO’s SSLV-D3 successfully launches EOS-08 Earth Observation Satellite

Introduction

6The Indian Space Research Organisation (ISRO) successfully launched the Earth Observation Satellite EOS-08 aboard the Small Satellite Launch Vehicle (SSLV)-D3 on 16 August 2024 at 9:17 AM from Satish Dhawan Space Centre, Sriharikota. This was the third and final developmental flight of SSLV, marking the completion of SSLV development phase.

About SSLV-D3 Mission

• SSLV (Small Satellite Launch Vehicle) is a three-stage rocketwith:
  • All solid propulsion stages
  • Velocity Trimming Module (VTM) (liquid-based terminal stage)
• Height: ~34 m
• Payload capacity: Up to 500 kg to Low Earth Orbit (LEO) (~500 km)
• Key Features:
  • Low cost
  • Quick turnaround time (~72 hours)
  • Minimal launch infrastructure
  • On-demand launch capability
  • Ability to launch multiple satellites

Significance:

• Marks entry of ISRO into small satellite launch market
• Enables commercial launches via NSIL (NewSpace India Ltd)
• Demonstrates repeatable flight performance

EOS-08 Satellite: Key Features

• Type: Earth Observation Satellite
• Mass: ~175.5 kg
• Power generation: ~420 W
• Orbit: Circular LEO at 475 km altitude
• Inclination: 37.4°
• Mission Life: 1 year
• Built on Microsat/IMS-1 bus

Primary Objectives

• Development of microsatellite platform
• Payload compatibility with microsatellite bus
• Testing new technologies for future operational satellites

Payloads on EOS-08

1. Electro Optical Infrared Payload (EOIR)

• Operates in:
  • Mid-Wave IR (MIR)
  • Long-Wave IR (LWIR)
• Capabilities:
  • Day & Night imaging
• Applications:
  • Surveillance
  • Disaster monitoring
  • Environmental monitoring
  • Fire detection
  • Volcanic activity observation
  • Industrial & power plant monitoring

2. GNSS-Reflectometry Payload (GNSS-R)

• Uses GNSS signals for remote sensing
• Applications:
  • Ocean surface wind analysis
  • Soil moisture assessment
  • Cryosphere studies (Himalayan region)
  • Flood detection
  • Inland waterbody detection

3. SiC UV Dosimeter

• Measures UV irradiance
• Acts as high-dose gamma radiation alarm sensor
• Application:
  • Used in Gaganyaan Mission (Crew Module monitoring)

Technological Advancements in EOS-08

Integrated Avionics System (CBSP Package)

• Combines:
  • Communication
  • Baseband
  • Storage
  • Positioning
• Supports up to 400 Gb data storage
• Uses COTS (Commercial Off-The-Shelf) components

Advanced Satellite Systems

• Micro-DGA (Dual Gimbal Antenna)
• M-PAA (Phased Array Antenna)
• Flexible Solar Panel
• Embedded battery & PCB structural panel

Miniaturisation & Precision

• Antenna pointing speed: ~6°/sec
• Accuracy: ±1°

Thermal & Structural Innovations

• Pyrolytic graphite sheet diffuser
  • High thermal conductivity (350 W/mK)
• Materials used:
  • Germanium Black Kapton
  • STAMET (Si-Al alloy)
  • AFE BGA, Kintex FPGA

Communication & Data Transmission

• X-band data transmission
• Uses:
  • Pulse shaping
  • Frequency Compensated Modulation (FCM)

Battery & Power Management

• SSTCR-based charging system
• Sequential regulation at 6 Hz

Indigenisation & Innovation

• Indigenous solar cell fabrication
• Nano-Star Sensor
• Reaction wheel isolators (vibration reduction)
• Single antenna interface for TTC & SPS
• Auto-launch pad initialization feature

Assembly & Testing Innovation

• Hinge-based fixture system
• Reduces Assembly, Integration & Testing (AIT) time

Additional Mission Outcomes

• Satellite injection: ~13 minutes after launch
• SR-0 Demosat (0.2 kg) also placed in same orbit
• Demonstrates small satellite ecosystem capability

Conclusion

The SSLV-D3 EOS-08 mission represents a major milestone in India’s space programme, completing the SSLV developmental phase and positioning India as a competitive player in the global small satellite launch market, while also showcasing advanced indigenous satellite technologies for future missions including Gaganyaan.