Ever wonder how Indian astronauts communicate with Earth without a signal? they use…

In a historic moment for India’s space sector, Indian Air Force Group Captain Shubhanshu Shukla reached the International Space Station (ISS) as part of the Axiom-4 mission. The Ax-4 mission was launched on June 25 from NASA’s Kennedy Space Center, which is located in Florida. Group Captain Shukla, along with other astronauts, took a 28-and-a-half-hour journey on the Dragon spacecraft to reach the ISS. He held a video call with Prime Minister Narendra Modi and also interacted with several Indian students. But do you know how astronauts communicate with Earth when space has no network or mobile towers?

Sound Waves Cant Travel As Space Has No Air

As we all know, space has no air, and sound waves cannot travel without air, making conventional voice communication impossible. Since sound waves can’t be used, astronauts rely on radio waves to communicate with Earth. Notably, sound is a mechanical wave that cannot travel on its own and needs a medium like air or water.

The Only Mode Of Communication Is Radio Waves

In order to communicate with Earth, astronauts use radio frequencies which is a type of electromagnetic radiation. These waves don’t need any medium such as air or water to travel. Astronauts use microphones and transmitters, which are fitted in their helmets, that convert speech into radio signals. These signals then transmitted to Earth through satellite antennas. The ground stations catch these frequencies and convert them back into audio.

NASA’s Global Communication Network

NASA’s Space Communications and Navigation (SCaN) system maintains constant contact with spacecraft. This network uses large, strategically placed antennas to ensure uninterrupted communication.

Astronauts Use Relay Satellites

ISS uses relay satellites to communicate with the Earth. These satellites hover in high Earth orbit and act as intermediaries, catching signals from astronauts and sending those signals to ground stations. The same pattern will be followed whether it’s a voice message, video call or an image.

Laser-Based Space Communication Is The Future

NASA is exploring laser communication technology as a faster, higher-quality alternative to the current radio-based system used for space communication. While radio waves and antenna networks currently maintain contact with spacecraft, laser systems, employing infrared beams, are being developed to significantly improve data transmission speed and clarity.

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