Star Light
Hal Clement
 Star Light is set several decades after the events of Mission of Gravity. It takes place mostly on the supergiant planet Dhrawn, which some suspect of being a failed star. The planet has an ammonia/water atmosphere with some oxygen, at temperatures ranging from 70 kelvins to almost the freezing point of water. The planet rotates extremely slowly, taking around two months for one revolution. It also has a long eccentric orbit around its star, which is a red dwarf, Lalande 21185. Much of the planet's heat seems to come from within. The gravity at the surface is 40 times the Earth's. Almost everything about the planet defies scientific theory, including its size, lack of hydrogen, its temperature, and the presence of free oxygen in its atmosphere. A consortium of spacefaring races, including humans, recruits Mesklinites, the centipede-like natives of the high-gravity planet Mesklin, to explore Dhrawn. The recruits include Barlennan and Dondragmer, respectively the Captain and First Mate of the Bree, a merchant vessel of Mesklin, which sailed to Mesklin's south pole to rescue a probe sent by humans. Now, thanks to institutes of learning set up on Mesklin, the natives have produced capable explorers who can go where other races cannot. Barlennan is in command of the main base on Dhrawn while Dondragmer commands a "land cruiser", the Kwembly. This is a tracked vehicle about 30 meters long, 6 meters high and the same wide. It is designed to move like a large worm on independently steerable trucks. The power is supplied by self-contained fusion generators but the controls are simple pulley-and-rope systems using Mesklinite materials which the crew can repair themselves. There are several more cruisers, and each has audio/video links for communication with satellites. The humans and others are on a satellite in synchronous orbit above the explorers on the ground. Unfortunately the planet's slow rotation means that they are about 10 million kilometers above the surface, and signals take over 30 seconds to travel to the satellite. Real time conversations are therefore impossible. On the satellite are linguist "Easy" Hoffman and her son Benj, who is both an engineer and a linguist. Both speak fluent Stennish, the Mesklinite language, and have formed close personal relationships with the explorers on the surface. They are later joined on the satellite by Ib Hoffman, Easy's husband and Benj's father. One of the cruisers, the Esket has apparently suffered a catastrophe and all the crew have vanished, much to Easy's dismay. The cruisers communicators still function, but all they show are views of a deserted ship. In reality, Barlennan is executing a complicated deception. A wily negotiator who successfully blackmailed the humans into giving him technology in Mission of Gravity, he is apparently plotting to gain yet another advantage from the situation he created. The exact nature of his objectives is unclear. Soon, however, the Kwembly is in very real trouble. As the planet warms, the complicated phase transitions of water and ammonia mixtures at these low temperatures mean that a frozen lake can melt in seconds, carry the ship off in a flood, and equally suddenly leave it hung up on large rocks, unable to move as the liquid around it freezes again, trapping some of the crew below the surface in their protective suits. These events, along with some bad timing, lead to the discovery of Barlennan's trickery when Easy recognizes a friend of hers from the Esket as he appears, as if from nowhere, but actually from one of the dirigibles that Barlennan is clandestinely using to move his men and materiel around. The Hoffmans would prefer to deal honestly with the Mesklinites, but they have to deal with the prejudices, not only of fellow humans with political motives, but with the more paranoid of the non-human supervisors of the mission. Having an inkling of what Barlennan is really after, Ib Hoffman finally breaks the deadlock with an idea that will save the crew of the Kwembly and make the mission successful beyond the dreams of its planners.