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Add YoursThere were a dozen of the surface vehicles, with their wide balloon tires and pressurized cabins, in the great servicing chamber. His father must have been expected, for they were led at once to the little scout car waiting by the huge circular door of the airlock. Tense with expectancy, Marvin settled himself down in the cramped cabin while his father started the motor and checked the controls. The inner door of the lock slid open and then closed behind them: he heard the roar of the great air pumps fade slowly away as the pressure dropped to zero.Then the "Vacuum" sign flashed on, the outer door parted, and before Marvin lay the land which he had never yet entered.
The vehicle is different because it is equipped and made for space travel. The interior is pressurized and cramped,
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If I Forget Thee, O Earth...