Eyes in the Sky: ISRO's RISAT-1B set to sharpen India's vigilance

After witnessing the tension at the borders, the ability to maintain unwavering surveillance over national territories is paramount. In a pursuit of enhancing vigilance, the Indian Space Research Organisation (ISRO) is poised to boost India's strategic surveillance capabilities with the upcoming launch of RISAT-1B, an advanced Earth observation satellite. The satellite is scheduled to lift off from the Satish Dhawan Space Centre in Sriharikota on 18 May 2025, aboard the Polar Satellite Launch Vehicle (PSLV-C61).

RISAT-1B, also designated as EOS-09, is not just another satellite; it represents the seventh flight unit in India's highly successful Radar Imaging Satellite (RISAT) programme. It is developed by ISRO and is engineered to provide all-weather, day-and-night imaging. This capability is crucial for a nation with extensive and diverse borders, often subject to challenging weather conditions that can impede traditional optical surveillance.

The satellite's primary instrument is a sophisticated C-band Synthetic Aperture Radar (SAR), capable of penetrating cloud cover, rain, and darkness to deliver high-resolution imagery of the Earth's surface, reportedly with a resolution of up to one meter. Weighing in at 1,710 kg and generating 2200 W of power, RISAT-1B will be injected into a 529 km sun-synchronous polar orbit by ISRO's trusted PSLV-C61 in its XL configuration. Its orbit is precisely calibrated with an Equator Crossing Time (ECT) of 06:00 (descending), enabling regular revisits to areas of interest.

RISAT-1B features multiple imaging modes, including spotlight mode for detailed observation of small areas and broader scan modes for wider area surveillance. This versatility makes it an invaluable tool for monitoring India's sensitive borders with Pakistan and China, detecting infiltrations, tracking suspicious movements, and supporting anti-terrorism operations. Its deployment is seen as particularly timely, reportedly expedited in the wake of recent national security concerns and events like "Operation Sindoor," representing the government's emphasis on bolstering surveillance infrastructure.

The stream of vital data from RISAT-1B will be downlinked in the X-band to appointed ground stations. The National Remote Sensing Centre (NRSC) in Hyderabad will play a key role in the dissemination of this off-line data, ensuring it reaches relevant defence and civilian agencies.

While the specific cost for RISAT-1B has not been publicly itemised, it is a key component of the ambitious Space-Based Surveillance-3 (SBS-3) mission. This broader initiative, approved in October 2024 with a reported budget of approximately USD 3 billion, envisages a constellation of 52 satellites dedicated to enhancing India's surveillance network.

Beyond its paramount role in national security, RISAT-1B's capabilities extend to a wide array of civilian applications. The data procured will be instrumental in disaster management, providing critical information for flood mapping, landslide monitoring, and assessing damage during natural disasters. In agriculture, it will aid in crop monitoring, soil moisture estimation, and forestry surveys. This dual-use nature significantly enhances the return on investment in such advanced space infrastructure, contributing to socio-economic development alongside strategic defence.

RISAT-1B represents a continuation of ISRO's acclaimed RISAT series, which has consistently proven its mettle in providing crucial geospatial intelligence. It will complement India's existing fleet of earth observation satellites, including the Cartosat and Resourcesat series, further strengthening the nation's indigenous space-based surveillance network.

The launch of RISAT-1B is not just another feather in ISRO's cap; it is a definitive statement of India's commitment to leveraging cutting-edge space technology for safeguarding its territory, ensuring the security of its citizens, and fostering national development. As RISAT-1B prepares to take its place as India's new 'eye in the sky,' it symbolises a significant stride in the nation's quest for self-reliance in critical strategic domains.