You have to think brand name, NASA as a brand is a big plus. They could initially have just the space-food, then they could branch out to camping food as well, where they could basically sell the food you are used to, but with the NASA brand, they would probably make more money.
The only down side I can see is that many would object to the federal government going into business, and competing against private companies. So what they could do instead is to license the NASA brand. I'm sure NASA could make some money off of this. It might reduce our taxes (although minimally). I think licensing a brand like NASA is akin to other licensing agreements the feds are already doing. As long as they don't dilute the brand, or put it on bad products, we may as well make some money off of it as it is a national resource.