<span class="SFPTagline"> From SCIFIPEDIA </span>

Depending upon the scope of your definition, Military SF might be seen as a very large percentage of contemporary SF. Many space operas involve ships whose crews are described as being members of the armed forces, even though their mission might be scientific or exploratory, including virtually every Star Trek novel. The term is more commonly limited to stories in which actual military action takes place or is contemplated. Sometimes this involves battles in outer space, between ships and perhaps space stations, but in recent years it has more commonly been set on a planet torn by civil war or invasion. A very common element in military SF is the mercenary unit, hiring its services to one party or another, often subsequently double crossed by its employers or, in some cases, its superiors.

Although more popular in recent years than in the past, military SF has a well established tradition. In Andre Norton's 1956 novel Star Guard she anticipated many authors who followed with her story of a military unit that discovers its mission on a contested world has been compromised, and that their theoretical friends and enemies have made common cause against them. The most consistently entertaining stories involving mercenary units are found in the Falkenberg series by Jerry Pournelle, particularly "Silent Leges", a tradition followed by several others, most notably David Drake with his Hammers Slammers novels and short stories. Keith Laumer's Bolo series, in which supertanks of the future are guided by transplanted human brains, has also inspired imitators like Leo Frankowski.

Perhaps the single best known military SF novel is Robert A. Heinlein's Starship Troopers, which follows the training and early career of a young man in a future interstellar war. Gordon R. Dickson's Dorsai series has also remained quite popular, a blend of straightforward military SF and interplanetary politics. David Weber's Honor Harrington series similarly alternates between military and political confrontations. Most military SF glosses over the downside of war and combat, but Joe Haldeman addressed that issue head on in his Hugo and Nebula Award–winning The Forever War and its two sequels.

Haldeman is not the only writer to have attempted a more realistic portrayal of military life. Lois McMaster Bujold's novels set in the Barrayar universe often involve extensive military operations, but without losing sight of the human elements. David Feintuch's series about Nicholas Seafort is relentless in its depiction of the pressures placed on soldiers in a crisis. Elizabeth Moon's Once a Hero is similarly strong on characterization and debunks some of the romantic attitudes toward combat.

Other well-written military adventures in space have been produced by John Dalmas, William C. Dietz, Roland Green, John G. Hemry, Rick Shelley, Timothy Zahn, and the collaborative team of David Sherman and Dan Cragg. Occasionally writers have turned an openly satirical eye to the subject. Harry Harrison's Bill, the Galactic Hero is the best of these. Robert Asprin's Phule series is also entertaining.