New Delhi, June 4 -- The space race used to be a rich-nation flex. America, Russia, and then China shot rockets into orbit while the rest of the world watched on livestreams.

But India rewrote that script, landing near the Moon's south pole before anyone else, and placing an observatory in orbit to study the Sun from space. And it did so on budgets that wouldn't cover a single Hollywood space movie.

Now, ISRO is throwing open its doors to private players, the government is loosening foreign direct investment (FDI) rules, and a sector once locked behind government gates is suddenly buzzing with companies building satellites, propulsion systems and launch tech.

For investors, it's a rare chance to get in early on an industry that's quite...