NISAR and new space frontiers

The successful launch of the NASA-ISRO Synthetic Aperture Radar (NISAR) satellite on July 30 is possibly the most significant milestone for the Indian Space Research Organisation since the soft-landing of Chandrayaan-3 on the Moon in August 2023. The world’s most sophisticated and most expensive earth observation platform will scan the planet’s entire surface in astounding detail, every 12 days, creating a dataset unmatched in scale and clarity. About the length of a pickup truck, the satellite’s main body contains engineering systems and a first-of-its-kind dual-radar payload – an L-band system with a 25-cm wavelength and an S-band system with a 10-cm wavelength. Each system’s signal is sensitive to different sizes of features on Earth’s surface, and each specialises in measuring different attributes such as moisture content, surface roughness, and motion. These characteristics are important for studying a variety of natural surface conditions. When operating together, the two radars will collect data synchronised in time and location, extending the sensitivity of the measurements. For example, the S-band data will allow more accurate characterisation of shorter plants, such as bushes and shrubs, while the L-band data will sense taller vegetation such as trees. Terabytes of data generated each day will be free for researchers, who can more accurately predict the consequences of climate change, biodiversity loss, and the melting of the polar ice cap.

The decade-long collaboration between the two space agencies must not end with NISAR. Rather, it should inspire more advanced joint programmes as envisaged by the political leadership of the two nations. Long-duration human spaceflight missions, spaceflight safety, and planetary protection have been identified as some of the areas for initial collaboration. Space cooperation can also advance through industrial collaboration in connectivity, advanced spaceflight, satellite and space launch systems, space sustainability, space tourism, and advanced space manufacturing. India is also a signatory of the US-led Artemis Accords, which seek to provide a set of principles to enhance the governance of civil exploration and use of outer space.

The Indo-US space collaboration has come a long way from the days when Washington tried hard to prevent New Delhi from acquiring the cryogenic technology for rocketry. It was ironic that NISAR was launched using a GSLV that has a cryogenic engine in its core. The collaboration has led to the entry of Indian astronaut Shubhanshu Shukla to the International Space Station. His inputs will be vital in designing India’s own space station. The two countries would do well if they shield joint exploration of the outer world from the ongoing friction on the trade front.