India, July 28 -- The Nasa-Isro Synthetic Aperture Radar (Nisar) mission will lift off on Wednesday. At first glance, it's the world's most expensive Earth observation satellite: a $1.5-billion mission, 2,800 kg observatory, carrying two different radar frequencies (L-band and S-band), capable of detecting centimetre-level surface changes globally every 12 days. A technical marvel. And notably, its data will be freely available and open to the public.

But, Nisar is more than a satellite. It represents the quiet convergence of two space philosophies - one born from the urge to explore the planets, and the other grounded in the belief that space should serve people back home. Nisar is the first mission of its kind: a dual-band Synthetic Ap...