This is Showcase 1 (Tommy Tomorrow) , published by Mimosa (SA Magazine Co) +/- 1963-1964.
It reprints the cover and story from DC Comics' Showcase 46 (1963):
"Mission to Disaster"
Also reprinted is this story from DC Comics' Action Comics 250 (1959):
Tommy Tomorrow: "The Boy Planeteer!"
32 pages, glossy colour cover, black and white newsprint interior.
Here is the cover of issue 1 and DC Comics' original cover: