This is a scam as evidenced by any number of hoax websites.
I saw this on Facebook – Nigerian Lost in Space Needs $3 Million to Get Home: https://boingboing.net/2016/02/12/nigerian-astronaut-lost-in-spa.html. Definitely worth being this week’s Weirdness Wednesdays post. Looks like this scam has been around since at least early 2016, but it’s having a revival this month.
A friend fell for the Nigerian love scam even though she knew about Nigerian scams. She sent the supposed U. S. Army officer over $5,000 and asked me to help. I said no. If he were truly in the U. S. military and was stuck in Nigeria, contacting the American embassy or someone in the Army would have gotten him out of the country. He had no problem contacting my friend using the Internet. Worse for her, she said the I. R. S. hit her with a tax bill for sending that much money to Nigeria.
Other Weirdness Wednesdays posts: https://upsdownsfamilyhistory.wordpress.com/tag/Weirdness-Wednesdays/