My original tumblr post was here. This comics page was originally posted on Tumblr by Vintage Geek Culture who attributes it to Gil Kane. A minor mystery hovers around this comic, as the the Grand Comics Database does appear to have an entry for Astra: Girl of the Future, however there it is listed as a Tijuana bible. This particular page doesn’t betray any of that; the subject matter is too standard and the production values to high. It seems likely that the GCD entry is a parody of a real comic. A bit more searching, however, does turn up the story “The Mad Brain” with an Astra character in Sensation Comics #106 (1942).