John Glenn did not have any brothers or sisters
yup, their names are Charlie Glenn, Jake Glenn, David Glenn, Phillip Glenn, Phyllis Glenn, and Katie Glenn.
no
John and Annie Glenn had two children: John David (born 1945) and Carolyn Ann (born 1947).
John Glenn has never been to Mars, nor has any other human being.
stewie
4 sisters
John Glenn's full name is John Herschel Glenn, jr.
John Glenn's full name is John Herschel Glenn, jr.
No
No, john glenn is not single.
John Glenn's Wife's Name is Anne Glenn