Yes. For about a decade Carmack funded a significant amateur space rocket effort -- Armadillo Aerospace. That shut down because of lack of money to devote to

Yes. For about a decade Carmack funded a significant amateur space rocket effort -- Armadillo Aerospace. That shut down because of lack of money to devote to the project. See http://arstechnica.com/science/2013/08/john-carmacks-8m-pipe-dream-meets-reality-armadillo-aerospace-on-life-support/ http://arstechnica.com/science/2013/08/john-carmacks-8m-pipe... He reached $8 million put in before reaching the decision that was too expensive for a hobby.