#145 Heavy weather: Mission of Gravity (1954) by Hal Clement

The classic which helped to define hard science fiction

Whatever your definition of "hard science fiction", Hal Clement's 1954 novel Mission of Gravity is sure to meet it. Rich with meaty discussions of the hard sciences, and written with a stern adherence to scientific plausibility, Clement's third novel is one of the definitive works of hard SF. 

For more classic SF reviews and discussion, visit andyjohnson.xyz. To get free weekly classic SF updates, sign up here.

Transcript

In the November 1957 issue of Astounding Science Fiction, the critic P. Schuyler Miller used the term “hard science fiction” in print for the first time. He had coined a term to describe SF that aspires to scientific rigour and plausibility, a term still in common use in SF circles today. But scientifically rigorous SF was not new, and one of the definitive novels in this style had been published years earlier: Hal Clement’s Mission of Gravity (1954). 

Set on one of the most famously strange worlds in science fiction, this 1950s classic is about cooperation between humans and aliens in a uniquely hostile environment.

From Harvard to Hal’s hellworlds

Born Harry Clement Stubbs, Hal Clement (1922 - 2003), began publishing science fiction even before he finished his university studies. His first story, “Proof”, was published in Astounding in June 1942, while Clement was studying astronomy at Harvard. He joined the United States Air Force and crewed a B-24 Liberator in combat missions over Europe during the latter part of World War II. For many years, he taught chemistry and astronomy at the prestigious Milton Academy in Massachusetts. 

Mission of Gravity was Clement’s third novel - his first two were Needle (1950) and Iceworld (1953). All three were originally serialised by Astounding, under the editorship of John W. Campbell Jr. Throughout his career as a writer, Clement was known for his scientific rigour, grounded in his deep knowledge of the hard sciences. His stories and novels are frequently set on “puzzle planets”, or “hellworlds”, planets with highly specific conditions which differ greatly from Earth and provide his protagonists with ample scientific and engineering challenges. Mission of Gravity would become the definitive example of this type. 

Welcome to Mesklin

The novel is set entirely on Mesklin, a planet which exemplifies Clement’s “puzzle planet” concept and remains a famous location in the grand tradition of hard SF. Located in the 61 Cygni star system, its properties are extreme. It has 16 times the mass of Jupiter, and rotates very quickly resulting in a day that lasts just under 18 Earth minutes. The peak temperature is -50 °C, and the planet is so cold that its oceans are made of liquid methane and ammonia falls as snow. 

The most notable aspect of this bizarre world is its gravity. At Mesklin’s poles the gravity is a crushing 700 times higher than that of Earth; at the equator, the planet’s rapid spin produces a centrifugal force that negates much of this, resulting in a comparatively bearable three times Earth gravity. It is Mesklin’s intense gravity that attracts the interest of starfaring humans. They cross the gap of 11 lightyears between Earth and 61 Cygni, intending to gather critical data that they hope could make possible the construction of an anti-gravity device. Unfortunately, their lander becomes stranded at one of the poles, unable to take off again. This is where Clement’s plot begins.

With help from little friends

As hostile as Mesklin is to fragile, fleshy humans, it does have intelligent life of its own which is adapted to local conditions. Human explorer Charles Lackland, who is stationed in a special dome to protect him from the comparatively mild gravity of the equator, has befriended a uniquely brave and industrious local. Barlennan is the captain of the Bree, a sailing ship which plies the methane oceans for trade and profit. He is also, like all Mesklinites, a one-foot long, many-legged centipede-like creature, with a hardened exoskeleton. 

Barlennan agrees to take the Bree and its crew on an epic journey to recover the human-built equipment from the pole.The captain is a canny operator, however, and may ask Lackland and his colleagues on an orbiting station for a greater payment than they had planned to give.

Episodes in hard and soft science

The journey of the Bree consumes almost all of Mission of Gravity and is quite episodic in structure. Each of these episodes is a means for Clement to explore the geography, biology, meteorology, and especially physics of his imagined planet. Early on, Lackland rather rudely picks up Barlennan and puts him on top of his “tank”, an armoured vehicle designed to cope with Mesklin’s gravity. Barlennan is initially terrified - he knows that in such high gravity, a fall from the tank’s roof could be fatal. Clinging on for dear life, he soon begins to enjoy the ride.

Later, Lackland and the Bree crew find themselves in a city built by other Mesklinites from a different culture. On the way in, they notice many boulders positioned at the rim of the bowl-like city. They realise almost too late that the locals have built their city as a giant trap - in high gravity, the boulders can be rolled down with such immense force that even Lackland’s tank would be destroyed. Time and again, the protagonists encounter challenges which reflect Mesklin’s unique conditions, and find a solution rooted in real science and engineering.

Clement’s hard science credentials in Mission of Gravity are hard to fault, but the same cannot be said for other elements of the novel. The deployment of so-called “soft” sciences is much more dubious. In particular, Barlennan’s ability to learn English fluently within six weeks is absurd on its face. Clement makes little or no attempt to give the Mesklinites their own culture or mode of speech - even when the novel opens, Lackland and Barlennan speak as if they attended the same California technical college.

Legacy of the Mission

Decades on, Clement's breakthrough novel is a little stilted and dated. The lengthy explanations of technical challenges come at the expense of character development or any kind of cultural plausibility. More recently, some of those writers who followed in Clement's footsteps have been more successful in these respects.

In some ways, Mission of Gravity is surprising for a novel written in the early 1950s. Strikingly, Clement did not write a story of human chauvinism or supremacy. While Barlennan is only really alien in physiological terms, and not in cultural ones, he is a more than equal partner in the story. Sometimes, he accepts suggestions from Lackland but more often it is Barlennan’s ingenuity and knowledge of his own world that wins the day. Clement makes the point that it is indigenous people who know their own environments best. It is also interesting that at no point do the humans look down on their Mesklinite partners, despite their distinctly non-humanoid appearance. 

Mission of Gravity lacks the depth of character and pace to completely transcend its early 1950s origins - but it remains a key milestone in hard SF, one with some perhaps surprising perspectives for its era.