Cover art
Steele, Allen. The Tranquillity Alternative. Ace 1996 (cover art by Bob Eggleton).

Steele, Allen. Alternate Space
Divergence: 1942 CE
What if: Warned that Nazi Germany was developing a trans-Atlantic rocket, the US started a crash rocket development program headed by Robert Goddard.
Series note: Series containing the short stories "Goddard's People" and "John Harper Wilson" and the novel The Tranquillity Alternative.

Steele, Allen. "Goddard's People"
Divergence: 1942 CE
Summary: A history of Project Blue Horizon and its critical race to prevent a Nazi rocket from bombing New York. Concludes with mention of the first manned mission to Mars in 1976.
Series note: An Alternate Space story.
Published: In Isaac Asimov's Science Fiction Magazine, July 1991; What Might Have Been? Volume 3: Alternate Wars (eds. Gregory Benford and Martin H. Greenberg), q.v.; and Rude Astronauts: Real and Imagined Stories, Legend 1992 (0099260018), Old Earth 1993 (1882968018BUY), Ace 1995 (044100184XBUY).
— Revision of "Operation Blue Horizon", in Worcester Monthly, September 1988.

Steele, Allen. "John Harper Wilson"
Divergence: 1942 CE
Summary: In 1969, the US government plans to claim the moon, but the commander of the first manned landing goes in peace for all mankind.
Series note: An Alternate Space story.
Published: In Isaac Asimov's Science Fiction Magazine, June 1989; and Rude Astronauts: Real and Imagined Stories, Legend 1992 (0099260018), Old Earth 1993 (1882968018BUY), Ace 1995 (044100184XBUY).

Steele, Allen. The Tranquillity Alternative
Divergence: 1942 CE
Summary: In 1995, the U.S. is about to decommission its nuclear missiles at Tranquillity Base and sell the installation to the Germans, but saboteurs are at work.
Series note: An Alternate Space novel.
Published: Ace 1996 (0441002994BUY), 1997 (0441004334BUY).
Original in: English.
Translation: Italian by Roberto Marini as La fortezza sulla Luna, Mondadori 1996.