Critical Difference by Murray Leinster — Read

The sun was halfway toward mid-sky, and still attended by its sun-dogs, / though they were fainter than at the horizon. The sky was darker. The / mountain peaks reached skyward, serene and utterly aloof from the / affairs of men. This was a frozen world, where there should be no / inhabitants. The city was a fleet of metal hulks, neatly arranged on / the valley floor, emptied of the material they had brought for the / building of the colony. At the upper end of the valley the landing-grid / stood. It was a gigantic skeleton of steel, rising from legs of / unequal length bedded in the hillsides, and reaching two thousand feet / toward the stars. Human figures, muffled almost past recognition, / moved about a catwalk three-quarters of the way up. There was a tiny / glittering below where they moved. They were, of course, men using / sonic ice-breakers to shatter the frost which formed on the framework / at night. Falling shards of crystal made a liquidlike flashing. The / landing-grid needed to be cleared every ten days or so. Left uncleared, / it would acquire an increasingly thick coating of ice. In time it could / collapse. But long before that time it would have ceased to operate, / and without its operation there could be no space travel. Rockets for / lifting spaceships were impossibly heavy, for practical use. But the / landing-grids could lift them out to the unstressed space where Lawlor / drives could work, and draw them to ground with cargoes they couldn't / possibly have carried if they'd needed rockets.

Massy reached the base of the grid on foot. It was not far from the / village of drone-hulls. He was dwarfed by the ground-level upright / beams. He went through the cold-lock to the small control-house at the / grid's base.