In which the travellers, gazing solemnly upon the distant Earth and conjecturing their uncertain fate, debate the perplexing mechanics of their celestial voyage and the perplexing motions of their projectile as it dances between two great gravitational powers. They resolutely prepare to employ the last means at their disposal—the recoil of their rockets—at the critical moment of gravitational balance, as they await with mingled hope and dread the unknown consequences of their daring journey.