A "weighing scale" in space: How to measure body mass in microgravity?

During the journey of space exploration, astronauts' health monitoring is particularly important. As one of the key indicators for assessing health status, body mass is not only a basic parameter for assessing health, but also reflects the physiological changes of astronauts in space. During long-term space stays, changes in astronauts' body mass can provide important information about their metabolism, fluid balance, and muscle atrophy. This information is crucial for adjusting diet, exercise plans, and even predicting and preventing space diseases.

On Earth, we can measure it with a simple scale. However, in the microgravity environment of space, measuring body mass becomes a technical challenge. So, how do astronauts complete this measurement in space? On Earth, the scales we are used to using do not work in space, because in a microgravity environment, traditional measurement methods fail. Therefore, scientists have developed a special "space scale" - a mass meter. This instrument can overcome the measurement difficulties brought about by microgravity and accurately measure the body mass of astronauts.

The design principle of the mass measuring instrument is based on Newton's second law, that is, force equals mass multiplied by acceleration. When using it, astronauts will be fixed on a special bracket, and then a known constant force will be applied through a constant force mechanism to make the astronauts move in a uniformly accelerated straight line in a microgravity environment. By accurately measuring the displacement, speed and time during this movement, the instrument can calculate the acceleration and then deduce the astronauts' body mass based on Newton's second law.

With the continuous advancement of space technology, the mass measuring instrument has also undergone many upgrades and improvements. From the first generation to the second generation, and then to the latest optimized version, the scientific research team has made great efforts to improve the measurement accuracy, stability and ease of operation. These improvements not only improve the accuracy of the measurement, but also make the astronauts' experience in mass measurement more comfortable and efficient.

For astronauts, the process of measuring their body mass using a mass meter is relatively simple. They first need to be fixed on the bracket in a specific way to ensure that all parts of the body are placed correctly. Then, a teammate pushes the bracket to the specified position and waits for the bracket to reset. Finally, the astronaut's body mass can be quickly obtained through the instrument's built-in calculation system.

Measuring body mass in space is a complex and sophisticated technology that integrates knowledge from multiple fields such as physics, biomedicine, and aerospace engineering. Through this technology, we can not only better understand the physiological state of astronauts in space, but also provide a more solid health protection foundation for future space exploration.

Review: Xinhuanet Science Department