The Indian Space Research Organisation (ISRO) achieved another milestone on Friday morning by successfully launching the third and final developmental flight of its Small Satellite Launch Vehicle (SSLV-D3) from the Satish Dhawan Space Centre in Sriharikota. This mission carried the 175-kg Earth Observation Satellite EOS-08, as confirmed by ISRO. This flight marks the last SSLV mission directly overseen by ISRO, with future missions transitioning to the private sector.
The SSLV is a small launch vehicle specifically developed by ISRO to meet the growing demand for launching small and micro-satellites into low Earth orbit (LEO). Capable of carrying payloads up to 500 kg, the SSLV was designed with commercialization in mind, offering a cost-effective and flexible solution for satellite deployment. This makes it an appealing option for various commercial space ventures globally, especially as the demand for launching smaller satellites continues to rise.
Measuring just 2 meters in diameter and 34 meters in length, the SSLV uses three solid-fuel stages and a final liquid-fuel stage. The liquid-fuel stage is employed to make precise velocity adjustments necessary for placing satellites into their designated orbits. This flexibility in launching small satellites has made the SSLV an attractive option in the increasingly competitive space launch market.
Following the successful launch, ISRO announced on its social media platform X (formerly Twitter), “The third developmental flight of SSLV is successful. The SSLV-D3 placed EOS-08 precisely into the orbit.” The launch of EOS-08 marks a significant achievement for ISRO, demonstrating the reliability of the SSLV platform and its capability to meet both national and international demands.
EOS-08 Mission and its Objectives
The EOS-08 mission aims to develop and deploy a microsatellite equipped with advanced payloads and to incorporate new technologies essential for future operational satellites. Built on the Microsat/IMS-1 bus, EOS-08 carries three primary payloads: the Electro Optical Infrared Payload (EOIR), the Global Navigation Satellite System-Reflectometry (GNSS-R) payload, and the SiC UV Dosimeter.
1. Electro Optical Infrared Payload (EOIR): This payload captures images in the Mid-Wave Infrared (MIR) and Long-Wave Infrared (LWIR) bands, both during the day and night. The EOIR is designed for a wide range of applications, including satellite-based surveillance, disaster monitoring, environmental observation, fire detection, and industrial and power plant disaster monitoring. It can also monitor volcanic activity.
2. Global Navigation Satellite System-Reflectometry (GNSS-R) Payload: This payload showcases the capability of GNSS-R-based remote sensing for various applications. These include ocean surface wind analysis, soil moisture assessment, cryosphere studies in the Himalayan region, flood detection, and monitoring inland water bodies.
3. SiC UV Dosimeter: This payload monitors UV irradiance at the viewport of the Crew Module in ISRO’s upcoming Gaganyaan mission. It also functions as a high-dose alarm sensor for gamma radiation, further enhancing ISRO’s capacity to monitor and manage space-based environmental conditions.
Transition to Private Sector Operations
This SSLV-D3 mission is particularly notable as it is the final SSLV launch directly conducted by ISRO. Moving forward, SSLV missions will be handled by private companies, signaling a significant shift in India’s space operations landscape. ISRO’s commercial arm, NewSpace India Limited (NSIL), has already signed a memorandum of understanding (MoU) with various international partners. For instance, NSIL has partnered with the Australian company Space Machines Company to launch a satellite that can repair other satellites while in orbit. This future mission will be one of many that NSIL will oversee as ISRO continues to encourage private sector participation in space exploration.
Overcoming Past Challenges
The SSLV program has not been without its challenges. The first developmental flight of the SSLV in August 2022 narrowly missed its target. However, ISRO quickly addressed the issues, and by February 2023, the SSLV successfully placed three satellites into a 450-km circular orbit, marking a significant recovery and demonstrating the resilience of the program.
With the successful launch of the SSLV-D3, ISRO has completed the developmental phase of its smallest rocket, paving the way for future missions to be carried out by private entities. This shift is expected to give a significant boost to NSIL and further solidify India’s position in the global space market.
The successful launch of SSLV-D3 carrying the EOS-08 satellite represents a crucial step forward for ISRO’s small satellite program. By completing this final developmental flight, ISRO has demonstrated the SSLV’s reliability and versatility, ensuring that India remains a key player in the global space industry. The transition to private sector operations will likely further enhance India’s space capabilities, catering to the growing demand for small satellite launches in low Earth orbit.
