How Can Astronauts Communicate in Space: The Role of Radio Technology

Radio technology, a communication method that was invented more than a century ago, plays a crucial role in facilitating communication among astronauts both inside and outside the International Space Station (ISS) and other space missions. This article explores the unique challenges of communication in space and how astronauts use their technology to overcome these hurdles.

Communication in the ISS

When astronauts are operating inside the ISS or similar space stations, air-filled environments present minimal challenges for communication. Atmosphere provides a medium for sound waves to travel, allowing astronauts to talk directly without any specialized equipment. The habitual communication environment ensures that astronauts can conduct their daily operations without the need for any additional devices.

Radio Technology for Spacewalks

During spacewalks, when astronauts must venture outside the protection of a space station, the challenges of communication become more pronounced. Sound cannot propagate through space because it requires a physical medium to travel through, and there is a vacuum in space. As a result, astronauts need a different approach to communicate with each other and with ground control.

The essential piece of equipment for spacewalk communication is a radio device. Astronauts in space suits are equipped with radios that resemble walkie-talkies. These radios are designed to be voice-activated to prevent the astronauts from having to push buttons, a task that would be extremely difficult due to the gloves they wear on their hands. The equipment includes a microphone that allows astronauts to speak into their suits and a radio transmitter that sends their voice to the intended recipients, such as other astronauts or ground control.

Understanding Astronaut Communication

The process of communication begins with the astronaut, who uses the diaphragm to suck in air and then allows a controlled flow of air to pass through the vocal cords in the neck. The vibration of these vocal cords produces noise, which is further amplified and given resonance in the astronaut’s facial sinuses and mouth. The final act of speech is completed by the tongue and lips as they form the words that the astronaut's brain has decided to articulate. This vocal output is then transmitted through the space suit’s microphone to the radio device, which transmits the message over the radio waves to the ground crew or other astronauts.

Emergency Communication and Senses

While radio is the preferred and primary method of communication during spacewalks, there are scenarios where alternative methods might be necessary. In an emergency, two astronauts might be able to communicate by putting their helmets together and shouting, as the sound vibrations would travel through the material of the helmets. However, radio communication is the most reliable and practical solution, as it does not rely on the presence of a medium like air.

The space suit itself is designed with a radio transmitter and receiver integrated into the helmet. This built-in technology ensures that astronauts can communicate effectively regardless of their location or the presence of a physical medium. The use of radio technology has been essential for space exploration, especially during the 60 years since the first spacewalks were conducted.