This issue is a variant of The Unexpected (DC, 1968 series) #221 [Direct].
On-sale date from Comic Reader #198.
The astronauts consist of three men and three woman. However, five male names are given over the course of the story (Robert, Jeff, Al, Richard, and David). Two of the three women are named Karen and Abby.
Snyder credit per Gary Usher's Robin Snyder Comic Book List. Letters section includes a personal reply by Robin Snyder to a fan (Scott Hughes) over a letter he wrote. Comments from Jim Valencia, Jim Plank, Michael Iacca, Sue Randall, Charles David Haskell and Scott Hughes.