For works with similar titles, see Cosmos.
*Until September 1934, issues were published without copyright notice
- Chapter 1 – Faster Than Light by Roger Sherman Hoar as 'Ralph Milne Farley'
- Chapter 2 – The Emigrants by David Henry Keller
- Chapter 3 – Callisto’s Children by Arthur J. Burks
- Chapter 4 – The Murderer From Mars by Alfred Johannes Olsen as 'Bob Olsen'
- Chapter 5 – Tyrants of Saturn by George Henry Weiss as 'Francis Flagg'
- Chapter 6 – Interference on Luna by John W. Campbell
- Chapter 7 – Son of the Trident by Raymond A. Palmer as 'Rae Winters'
- Chapter 8 – Volunteers From Venus by Otis Adelbert Kline and E. Hoffman Price
- Chapter 9 – Menace of the Automaton by Abner J. Gelula
- Chapter 10 – Conference at Copernicus by Raymond A. Palmer
- Chapter 11 – The Last Poet and the Robots by Abraham Grace Merritt
- Chapter 12 – At the Crater’s Core by J. Harvey Haggard
- Chapter 13 – What a Course! by E. E. Smith
- Chapter 14 – The Fate of the Neptunians by P. Schuyler Miller
- Chapter 15 – The Horde of Elo Hava by L. A. Eshbach
- Chapter 16 – Lost in Alien Dimensions by Eando Binder
- Chapter 17 – Armageddon in Space by Edmond Hamilton