My list of famous older science fiction books to read has once again become one item shorter. (That’s a bit of a rhetorical flourish, I admit; I don’t actually have such a list. But you know what I mean.) While not necessarily one of the deepest novels I’ve ever read, Mission of Gravity (1954) deserves its reputation for several reasons: for being a noteworthy example of “hard” sci-fi, for its unique efforts at world-building, and for its depiction of aliens who are truly “alien” (at least physically).
Plot synopsis: Mesklin is a massive, rapidly-spinning planet shaped like a flattened sphere, with the variable gravity that would entail — from 3 gees at the equator to several hundred gees at the poles (the book says 700, but Clement later calculated it to be closer to 250 or so). Mesklin is very cold, and has methane oceans and a hydrogen atmosphere. All in all, not a nice vacation spot for humans. Nevertheless, human scientists are drawn to Mesklin to study it’s unique gravitational properties. Looking to gain new insights into the nature of gravity, in the hopes of achieving anti-gravity technology, they send an unmanned rocket bearing billions of dollars worth of special probes and equipment to the planet. Only problem is, once it sets down, near one of the poles, it is unable to overcome the incredible gravity and lift off again — oops! Enter the natives. The Mesklinites are small centipede-like creatures; evolution has forced them to stay close to the ground, since a fall of even a few inches in such gravity can be deadly. The scientists make contact with a group of wandering Mesklinite traders who travel all over the planet, and who are happy to enter into a relationship with the humans: the humans will help them expand their maps of Mesklin (using their satellites), and the Mesklinites will help the humans by traveling to their stranded rocket and retrieving the instruments. The bulk of the book is taken up by the Mesklinites’ journey over their world and the adventures they have along the way.
The novel is solid on its science, as far as I can tell, and that’s no surprise since Clement had a physics degree and taught high school science. Planetary specs like rotational period and temperature were meticulously calculated, and many other scientific aspects were plausibly detailed and explained, from geology to meteorology to ballistics. The only possible weakness I noticed was in the area of biology. I kept thinking of how astronauts in space have to exercise to fight the atrophy of their muscles and bones; it seems to me that the Mesklinites, who usually live nearer the polar regions, would face the same problem when spending any lengthy periods of time near the equator in very weak (to them) gravity. In fact, I think it’s likely that going from a few hundred gees down to 3 would cause them even more serious medical problems than that. But I’m not really sure about that. At any rate, aside from biology, the rest of the science here seems pretty reliable.
I can’t say that the characters were as strong, however. The problem with the humans was that they seemed mere sketches of people; we get only the most superficial sense of who they are and what drives them. The problem with the Mesklinites was that, although very alien in body, psychologically they seemed far too human.
Those flaws aside, though, this was still a worthy read. It worked well as an intriguing presentation of a vastly different environment, and a rousing adventure story.
Also of interest was Clement’s essay at the end describing some of the ideas and calculations that went into the novel. And I like his concept of a “game” between sf authors and readers: the author does his best to offer a world that is solid and consistent, and then the readers try their best to find any mistakes. I know that game — it’s all part of the fun.