And there is no where in the Constitution where it is forbidden,either.
There is the rub though isn't it? The Government has no power outside of what is deliniated to it through the Constitution. Essentially, that document is what "We the People," are ceding to the Government. It legally CAN'T do anything not writen there. It is a restrictive document, in that it restricts what the Government can do.
Unless you can find me the area covering Government run businesses in direct competition with private businesses, then the Government has no right to be running Nasa.
Care to join everyone else on the topic now?