DAYTON — Kroger Co. supermarkets on Monday began selling discounted tickets for the Vectren Dayton Air Show, scheduled July 7-8 at Dayton International Airport.

Vectren Corp. and Kroger are the principal corporate sponsors of the annual air show.

NASA astronaut Gregory H. Johnson, a 1980 graduate of what was then Park Hills High School in Fairborn who went on to fly two space shuttle missions on the orbiter Endeavour, is to appear at the air show, its organizers said Monday.

Johnson now serves at the NASA Glenn Research Center near Cleveland.

The air show will also feature NASA’s “Driven to Explore” exhibit, a multi-media display that tells the space agency’s story.

The Navy Blue Angels demonstration flying team is the headline act for the 2012 Dayton Air Show.