By Echo Wang, Milana Vinn and Joey Roulette NEW YORK, Jan 30 (Reuters) - SpaceX (SPAX.PVT) generated about $8 billion in profit on$15 billion to $16 billion of revenue last year, ​two people familiar with the company's results said, providing fresh insight into the ‌financial health of Elon Musk’s space company that is expected to go public later this year. SpaceX's most recent ‌financials, which have not been previously reported, led some banks to estimate that the company could raise more than$50 b ...