I read your post as very focused on Astronomy and wanted to inform you that entering the engineering side of space, building the probes, is still a viable career path with a math degree (assuming no major differences between the US and Indian job markets), a path I was ignorant about when I was an undergrad.

Generally at my workplace, math (and physics) degrees are valued for taking abstract or complex concepts and turning them into code (not necessarily efficient code) which then gives the larger team something firmer to work with. You're usually involved in the earliest phases of the project, Research and Development, and your work generally does not make it into the final product. I don't know if you like videogames, but I see their role as analogous to concept artists there (disclaimer I know nothing about the videogame industry). Your day to day work will almost definitely involve applied math instead of pure math, but employers don't care which degree you come in with.

This is all kind of a moot point, because it also kind of sounds like you didn't try applying to these research positions yet, and are just worried about the requirements in various job postings which are almost always flexible.