Marooned — E. Robert Dunn

After surviving an onslaught from a Tauron Occupation armada, the Pioneer Pod 4 has careened onto a supercontinent that centered itself on an alien planet's equator. Utopia Lost. A doomed globe has become the refuge for the stranded Aidennians, their prison. The pale primary sun burns away the morning chill and the clinging damp mist, revealing a gigantic silent world. Commander Capel and his crew of the Pioneer 4 notice their life-raft world is undergoing changes. The world's tri-suns are found to be on a countdown to detonation. The only course open to the Aidennians is to repair their impaired ship and evacuate.