DBT Bureau
Bhubaneswar, 17 August 2024
ISRO’s latest Earth Observation Satellite, EOS-08, was successfully launched on August 16 by the Small Satellite Launch Vehicle (SSLV)-D3 from the Satish Dhawan Space Centre in Shriharikota. Seventeen minutes after liftoff, the satellite was placed into a precise orbit 475 km above the Earth. The mission aims to advance several key objectives: designing and developing a microsatellite, creating payload instruments compatible with the microsatellite bus, and integrating new technologies essential for future operational satellites. By achieving these goals, EOS-08 will enhance Earth observation capabilities and support the development of more advanced satellite systems.
Built on the Microsat/IMS-1 bus, EOS-08 carries three payloads: Electro Optical Infrared Payload (EOIR), Global Navigation Satellite System-Reflectometry payload (GNSS-R), and SiC UV Dosimeter. The EOIR payload is designed to capture images in the Mid-Wave IR (MIR) and Long-Wave IR (LWIR) bands, both during the day and night, for applications such as satellite-based surveillance, disaster monitoring, environmental monitoring, fire detection, volcanic activity observation, and industrial and power plant disaster monitoring.
EOS-08 marks a significant advancement in satellite mainframe systems such as an Integrated Avionics system, known as the Communication, Baseband, Storage, and Positioning (CBSP) Package, which combines multiple functions into a single, efficient unit. This system is designed with cold redundant systems using commercial off-the-shelf (COTS) components and evaluation boards, supporting up to 400 Gb of data storage. Additionally, the satellite includes a structural panel embedded with PCB, an embedded battery, a Micro-DGA (Dual Gimbal Antenna), an M-PAA (Phased Array Antenna), and a flexible solar panel, each serving as key components for onboard technology demonstration.
The EOS-08 satellite features advanced technology, including miniaturized Antenna Pointing Mechanisms with a rotational speed of 6 degrees per second and ±1 degree accuracy. Its miniaturized phased array antenna enhances communication, while the flexible solar panel, incorporating a foldable substrate, GFRP tube, and CFRP honeycomb end panel, improves power generation and structural integrity. The use of a pyrolytic graphite sheet diffuser plate, with high thermal conductivity, reduces mass and supports various satellite functions. Additionally, the mission introduces a hinge-based fixture for integrating housekeeping panels, streamlining the Assembly, Integration, and Testing (AIT) phase. Novel technologies also include X-band data transmission with pulse shaping and Frequency Compensated Modulation (FCM), and an advanced battery management system using SSTCR-based charging and bus regulation.
The mission’s indigenization effort is evident in its solar cell fabrication processes and the use of a Nano-Star Sensor for Microsat Applications. Additionally, the inertial system benefits from reaction wheel isolators that attenuate vibrations and a single antenna interface is utilized for TTC and SPS applications. Thermal management is enhanced using materials such as AFE BGA, Kintex FPGA, Germanium Black Kapton, and STAMET (Si-Al Alloy) Black Kapton to handle the thermal properties of COTS components. The mission also incorporates an auto-launch pad initialization feature, further demonstrating its commitment to innovative mission management.
