The author compares space travel to ocean travel.
| Date | Publication | Publisher | Type | Page | |
|---|---|---|---|---|---|
| September 1965 |
|
Voices from the Sky: Previews of the Coming Space Age | Harper & Row | Nonfiction | 64 |
| 1966 |
|
Voices from the Sky: Previews of the Coming Space Age | Gollancz | Nonfiction | 64 |
| October 1967 |
|
Voices from the Sky: Previews of the Coming Space Age | Pyramid Books | Nonfiction | 60 |
| 1969 |
|
Voices from the Sky | Mayflower | Nonfiction | 59 |
| 1969 |
|
Voices from the Sky | Mayflower | Nonfiction | 59 |
| January 1971 |
|
Voices from the Sky: Previews of the Coming Space Age | Pyramid Books | Nonfiction | 60 |
| February 1980 |
|
Voices from the Sky | Pocket Books | Nonfiction | 70 |