The Seetee series is a science fiction series by American writer Jack Williamson (writing under the pseudonym "Will Stewart.") It consists of several books and stories set in the late 22nd century, amid space-dwelling Asteroid Belt colonists who are attempting to harness the titular seetee (a phonetic for "CT" or "contraterrene" matter, an obsolete term for antimatter) for the benefit of humanity, while also attempting to overthrow the tyrannical central authority of the High Space Mandate. Publication History All the prose entries in the series were initially published in short story-length installments in Astounding Science Fiction magazine: Collision Orbit (short story, July 1942) Minus Sign (short story, November 1942) Opposites—React! (novelette, serialized January–February 1943) Seetee Shock (novel, serialized February–April 1949) Seetee Ship (novel, 1951, fixup of Minus Sign and Opposites—React!) Beyond Mars (comic strip, 1952–1955) The short story Collision Orbit was published in the July 1942 issue, and was followed by "Minus Sign" (in the November 1942 issue) and "Opposites—React!" (two installments in January and February 1943.) After a six-year hiatus, Williamson revisited the setting with "Seetee Shock," a novel-length story serialized in Astounding between February and April 1949. The second and third stories were subsequently combined into a fix-up novel, released as Seetee Ship in 1951 by Gnome Press in an edition of 4,000 copies, and had subsequent reprintings from several publishers, including a Lancer omnibus edition in 1972. (The first story in the series, "Collision Orbit," was not collected in either of the Gnome Press books, or in any later omnibus editions.) The stories' internal chronological order is identical to their order of publication, save for the 1951 fix-up Seetee Ship, which is set before Seetee Shock (1949), the first part of the series to be published in book form. While directly based on the Seetee series, with a very similar setting, characters, and technology base, the 1952 comic strip Beyond Mars did not share the same continuity; the strip's departures included Mars and Venus being home to intelligent alien races, and neither solar-system politics nor antimatter played a major part in the story. Setting In the late 22nd century, many asteroids had been made habitable decades ago by "asterites" or Belt colonists through the use of paragravity technology. They are currently governed by the High Space Mandate, a joint multilateral administration run for the benefit of - the major planets of the solar system. The four constituent