Although the phrase "Submitted for your approval" from Rod Serling's opening narration has come to be closely identified with the show (and is often used by Serling impressionists), it is heard in four episodes: Cavender Is Coming (1962), In Praise of Pip (1963), and A Kind of a Stopwatch (1963), and at the end of "The Parallel" as well.
The comic book that Maggie is reading in the living room (just before she goes to get her father a cup of coffee) is Mysteries of Unexplored Worlds #32 (October 1962), a science fiction title published by Charlton Comics. Appropriately, the cover depicts a man floating helplessly in outer space.
The dialog spoken by Steve Forrest when he is in the capsule is taken almost verbatim from the capsule communications of John Glenn's Project Mercury first manned orbital mission of Friendship 7.
Steve Forrest played the protagonist, Major Robert Gaines, in this episode while his elder brother Dana Andrews played the protagonist, Paul Driscoll, in the preceding episode No Time Like the Past (1963).
At about 5 minutes in the "Capcom" communication centre, the consoles closest to the camera are the same as The Outer Limits (1963) "O.B.I.T." console (without the "mixing bowl"-shaped view screen). It's also seen as Mr. Waverly's overseas relay console occasionally in The Man from U.N.C.L.E. (1964).