I am unsure about private salaries but in govt. jobs, because it follows a rigid structure, the salary is still lower than what you might expect and is around the mark of 20-25 thousand dollars per year. It's similar to administrative services or depending on the position, equal to teachers/professors .
I have heard my cousin say that its hard for people to move outside because for example SpaceX/NASA couldn't hire non-American person because of laws and regulations due to security purposes.
From what I know, my cousin actually got some job offers when he had gone to give a speech recently from Management companies
20-25k$ in India isn't bad but strictly speaking, Computer science earns comparable in India at the same level.
The value of the job is mostly in govt rather than private and the benefit of it is that the work is much less stressful rather than private companies stress and just like how NASA has some prestige attached to it in America, same way goes for ISRO in India.
I think so, but I can only say it about my cousin to whom this field of line was suggested by one of my uncles was that the most major prospect of a government job.
Within India, there is a very strong prestige surrounding govt. jobs, like a lot.
The cousin whom I am referring to actually even studied and gave some exams after becoming a rocket scientist to get into a sub part of civil services just on the side (to get even better salary), I am unsure if this is an Indian specific phenomenon or not, but the prospect of the govt job for most people is the combination of comfort,prestige etc.
The prestige of the govt job is so much to many people that another person I know has spent 7 years solely dedicated towards getting to a govt. job and they still sadly don't have it but they are close to getting it :-( and they denied one of the most prestigious private institutions just for the effort to study solely for govt. job (though they are from civil engineering background), they would've completed their degree by now and atleast gotten a package close to the cousin working in rocket science itself.
My cousin actually wanted to go into computer science, I was in 4th or 5th grade back then and little me was already arguing that he should go rather to the CS college because of my love to computers ;) ,but my cousins really happy now so its all fair and in all fairness he and everyone thinks it was a decent decision.
Back during the process of his college and eventually going to ISRO, it wasn't that well known, but then two missions made it really have a spotlight it was before there were movies and the national fame and recognition that it got, before that nobody knew too much of ISRO but then suddenly literally everyone knew what ISRO :)
Also, the papers regarding ISRO if going through the college route is the JEE Mains/Advanced exam. Based on my personal observation, it is like the gakao exam and its a really really soul-sucking exam :-(
Most people who actually top that exam leave the nation anyway and the most focus is on the IIT or rather on prestige rather than passion. It sucks a little because Computer science is treated as prestige rather than passion which hurts people like me who are passionate getting grinded into dust :-(
Indian society and gatherings really feel very prestige/respect focused in many areas to me, though I am not sure if its an Indian phenomenon or not. Respect/comfort/stability seems to mean a lot more in my opinion
I wouldn't be too sure about the immigration part, when even a software engineer hire for a defence/defence adjacent job requires jumping through a number of bureaucratic hoops of security clearances. Even the companies with deep pockets don't always get the best people in the world -- they just get the best people that HR can actually hire.
Also, there are plenty of space companies that aren't in the US/UK/China who are hiring (and more willing to work with non-domestic employees since they're playing catch-up), and plenty of companies in US/UK/China who employ contractors that aren't subject to the same hiring restrictions as the first-party/defense-contracted company.
There are a lot more specialized/high-expertise roles here than the ones critical to a nation's space program (or fungible with making weapons). Random examples off the top of my head include crew/life support expertise, launch facility engineering, LEO consumer telecommunications, and more. Space hasn't been fully commodified/detached from government interests--not by a long suborbital burn--but it's moving that direction enough to thaw out the ability to immigrate for work a bit.