To be fair, Da Nang is centrally placed, has a nice coastal climate and has recently become an economic powerhouse. (And like most places in Vietnam, there are many thing to see for the historically, culturally or culinary inclined.) Interestingly, the mayor of Da Nang, who was responsible for dynamising the city, then became the ruler of Vietnam, which IMHO contributed to the country's recent economic growth.
If I ever go to Vietnam for work, that's where I intend to go. (Hanoi has a nice, beautiful central district, you would think you're in Paris in places, but its climate in summer is hot and wet. Saigon/Ho Chi Minh City is hot and dry in winter, and very hot and dry in summer. It is also a rather anarchic-looking city, mostly due to its explosive development.)
Unfortunately, while Vietnam is on the right side of the coast for launching rockets, it is also in a sort of tense place, not the kind of region where you want to launch rockets that could be confused with ballistic missiles. And as far as I know, there is also not much high-end aerospace industrial base, so you would have to start from scratch. Right now, I'd rather suggest to go to French Guyana. Try and directly negotiate with the French government to ease the bureaucratic nightmare. The PR angle of aerospace projects should help you. Also try and recruit as much local workforce as you can, there is an unemployment problem, so you will be on the good side of population and local authorities with the opportunity for development and employment.
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