Astronaut SistersBy: Julie Fortenberry Hold onto your juice boxeseverything floats in outer space! Set out for the stars in this warmhearted picture book ode to the transportive power of imagination. Fern and Rosie are astronaut sisters, ready to sail miles above the clouds. They slip on their boots (space boots). They strap on their helmets (space helmets). They pretend the swingset can launch them into the stars, and they lie on the grass gazing up at the real ones.