The National Science Foundation is also a division of the US government, and the National Sanitation Foundation (which goes by NSF) is also a well-known large and established private org.
The name would be "NSF Space Flight". Since the National Science Foundation is, unlike NASA, not involved with making rockets, a mix-up wouldn't be so bad.
The National Science Foundation is also a division of the US government, and the National Sanitation Foundation (which goes by NSF) is also a well-known large and established private org.
NSF is taken, too.