Final answer:
An astronaut's mass remains constant at 60 kilograms regardless of being in Earth orbit, on the Moon, or on Earth; however, her weight changes due to different gravitational forces, being weightless in orbit, and only one-sixth of her Earth weight on the Moon.
Step-by-step explanation:
The mass of an astronaut remains the same regardless of their location, whether on Earth, in orbit, or on the Moon. However, the astronaut's weight changes due to the difference in gravitational pull in these locations. On Earth, the astronaut's weight is the force due to Earth's gravity acting on her mass. In orbit, astronauts experience apparent weightlessness because they are in free-fall towards Earth, but their mass does not change. On the Moon, the astronaut's weight is only one-sixth of her weight on Earth, due to the Moon's weaker gravitational force which is about one-sixth of Earth's. For example, if the astronaut weighs 600 N on Earth (assuming an acceleration due to gravity of approximately 9.8 m/s2), her weight on the Moon would be 100 N. Nevertheless, her mass would remain a constant 60 kilograms in all locations.