Before the advent of digital machines, "computers" were people. Thousands of these specialists, often women, performed complex calculations by hand. For example, in the 1940s, the National Advisory Committee for Aeronautics (NACA), the predecessor of NASA, employed hundreds of such "calculators." Beginning in the 1880s, "Harvard computers"—women at the Harvard Observatory—hand-analyzed stellar spectra. Willemina Fleming discovered 10 new stars. Henrietta Leavitt, studying 1,777 variable stars, derived the Cepheid period-luminosity law, a key to cosmic distances. During World War II, "computers" at Aberdeen Proving Ground manually calculated ballistics tables. Each trajectory required 750 calculations, taking 40 hours! Later, six such women, including Kathleen Antonelli, became the first programmers of ENIAC, one of the pioneers of electronic computing. At NASA, these "living computers" were key to the space race. Katherine Johnson, Dorothy Vaughan, and Mary Jackson from Langley verified the most complex orbital flight calculations. In 1962, Johnson personally confirmed John Glenn's trajectory, ensuring his safe return. These remarkable women, often working in the shadows, performed countless calculations, laying the foundations of modern science and astronautics. Their precision and intellectual labor made possible what today seems routine, and their contribution remains indispensable.