Growing up in the 1920s on a dirt-poor farm in North Dakota, Mary Sherman's life was filled with chores--until she finally began school and discovered she loved to learn. Mary excelled at science, especially chemistry, and leaped at the chance to work in a laboratory during World War II designing rocket fuels. And when the US decided to enter the space race, Mary was chosen over her male colleagues to create the fuel to launch a rocket carrying America's first satellite. With courage and perseverance, Mary's hard work and calculations paid off, opening up a brand-new frontier for exploration. This STEM biography of an unsung and courageous woman in science will inspire and motivate young readers.