Hal Clement's 1979 novel, Mission of Gravity, is one of the tent poles of hard science fiction, fashioning an oblong world, Mesklin, where polar gravity reaches into the low 700g-range while counteracting centrifugal force at its equator allows for a more human-friendly 3g. When human explorers lose a probe at one of the planet's crushing poles, they enlist a crew of native sentient millipede sailors on a quest across their home world on a search and recovery mission. Though Frank Herbert's Dune series (or Niven's "Known Space") is the better-known planet-maker, Clement's work is at once less messianic and more thoughtful: less epic fantasy and more speculative, in the best sense of the word.

The strength of the piece is its clarity and wide accessibility, focusing as it does on the interaction between human handlers and their Mesklinite wards who, as it happens, have an extremely similar psychological constitution to the explorers of Earth's Age of Discovery. In its way, then, Clement's republished anthology, Heavy Planet is both science fiction and historical fiction -- mining the familiar for the possible in ways that any successful fiction must. It's seldom given over to technical jargon, relying instead on fairly elementary physics to dictate the twists and hardships faced by alien Barl and the intrepid crew of the Bree. The best moment is its quietest, as a human explorer lifts Barl from the ground to gain a better vantage point on top of a human vehicle: the good intentions of the man at direct odds with the instincts and phobias of a creature that has spent its life in mortal terror of heights and falls.

Exploring the equatorial regions in hopes of material gain, the sailors of the Bree are forced to traverse the middle of their planet, encountering odd native tribes and beasts along the way. Heavy Planet reads like Caesar's The Conquest of Gaul in some ways, anthropology by way of mythmaking. The crucial difference, however, lies in Clement's extrapolations of the possible based upon known science at the time of its 1953 writing, allowing explanations of the hard science to flow naturally from the narrative. That Heavy Planet is Clement's best-remembered and most beloved work is easy to understand: it's smart without being intimidating, based in science without being stale, and fantastic without being ludicrous -- all but unknown until now is the sequel, Star Light, published in 1970 with a returning cast of long-lived Mesklinites (Barl and first mate Dondragmer) and a new generation of human partners.

Star Light sets the millipede mariners on a new planet of interest to humanity, in closer partnership though still working through misunderstandings and unexpected dramas. Our alien allies are cast, this time around, as more duplicitous in their hunger for knowledge and, commensurately, more suspicious of humanity's desire to educate. Separated by a generation in the fiction and seventeen years in reality, this second Mesklin novel finds Clement falling more often into the sort of exhausting scientific explanation that Heavy Planet, for the most part, avoided. The story is not as strong this time around -- the main conflict of the piece stems from our human nervousness and impetuosity set against the relative calm and unflappable reaction to duress of the Mesklinites. A story based so firmly in the psychology of its protagonists places Clement a little outside of his strengths, marking Star Light as a nice passing of time for the fan (a little like Maria Doria Russell's unnecessary follow-up to The Sparrow), but conspicuously lacking in freshness and, most importantly, that illusion of ease.

Collected by Tor books under their impressive "Orb" imprint, Hal Clement's Mesklin work is collected in part (a more complete collection can be found courtesy the New England Science Fiction Association Press under the title: The Essential Hal Clement, Volume 3: Variations on a Theme by Sir Isaac Newton) in a handsome trade paperback that, besides the novels Mission of Gravity and Star Light, features a short story, "Lecture Demonstration," a novella, "Under," and a lecture, "Whirligig World." (The version of Star Light that appears in the collection -- titled Heavy Planet -- follows the Ballantine paperback text by request of Clement, marking it as the definitive edition of the work.) Neither "Lecture Demonstration" nor Under make much of an impression beyond the sort of snapshot themes that remind of Harlan Ellison's Medea anthology series. The former, in particular, begins to resemble a sort of "minute mystery" conceit that invites the reader to engage in pocket scientific sleuthery at the expense of narrative storytelling.

More successful in terms of unfolding a mystery against the backdrop of philosophy and, almost as a consequence, science fiction, is grandmaster A.E. Van Vogt's The World of Null-A. The first in a trilogy of books interested in theories of general semantics and the dissolving of Aristotelian logic (the "null-A" of the title), the novel was written in 1944 (published in serial form in 1945) and not surprisingly features a few conventions of the hardboiled detective genre that proliferated in film (as film noir) and popular culture in that period. The protagonist Gilbert Gosseyn is a hero with a mysterious past engaged in an Oedipal quest of self-discovery aided/impeded somewhere along the way by a femme fatale and eventually a monolithic entity. The novel predicts the work of Philip K. Dick, Alfred Bester, and Philip José Farmer in its almost German existentialist conceits of the slipperiness of identity and oppressiveness of society, finding itself amazingly current given the contemporary affection for post-modernism in genre pictures (The Matrix, Dark City, The Truman Show, and so on). Gosseyn gradually discovers that he is, in fact, only one of several Gilbert Gosseyns, each designated as "The One" prophesied to overthrow "the game," an artificial construct of a sentient machine designed to mold caste realities in the kind of sterile world imagined later in Logan's Run -- taking some of the elements from Huxley's philosophical benchmark Brave New World written over a decade previous.

More, Van Vogt's interest in Nietzche's superman raises thorny questions in regards to popular genre manifestations; The World of Null-A is less interested in science, despite its robotic planes and sympathetic computers, as it is in pushing the primacy of man's potential. Even as The World of Null-A explores terraforming (Venus is colonized after ice from Jupiter is towed there and allowed to integrate over the course of centuries), betrayals political and sexual, and even interplanetary warfare, the real hero of the novel is the power of logic and the Will to Power of the individual consciousness. Though certainly more esoteric than Clement's Mission of Gravity, Van Vogt's piece conveys impossibly complicated rhetorical theorems in ways offhand and surprisingly accessible. Both novels are seen as benchmarks of hard science fiction and both avoid the pitfalls that comprise the popular hard science fiction bogies of obsessive explanation and maudlin introspection.

Finding itself in a new edition, again courtesy Tor's "Orb" imprint, The World of Null-A remains a vital work nearly sixty years after its initial publication, raising questions about reality in an age where questions of personal identity and privacy are again hot topics. For all of Clement's pulp ease, his work remains more a nostalgic curiosity (and an enjoyable one) than a breathing document adaptable to each generation of readers: more Heinlein than Laumer, in other words. Van Vogt's novel is richer for its prophecy, made all the more fascinating for its status as the first major trade SF genre hardcover ever published in the United States -- despite a withering contemporary review by Damon Knight. Courageous and respectful of its audience, The World of Null-A is challenging and entertaining where Mission of Gravity is mostly just entertaining. There's room for both, certainly, and the real winner is Tor and "Orb," fast becoming the invaluable resource for print that Anchor Bay has already become for cinema and DVD.

Walter Chaw trained in British Romanticism and Critical Theory, and is now the chief film critic for FilmFreakCentral.net. Syndicated weekly in 32 small print journals, he is a nationally accredited member of the Online Film Critics Society. His previous reviews in Strange Horizons can be found in our Archive.