Talking to the moon and beyond : Deep Space Network Frequency Utilization

Goldstone Deep Space Communications Complex in California

 Have you ever wondered how the earthlings heard the words, "That's one small step for man, one giant leap for mankind." in 1969? Over 50 years have passed and we've progressed a lot since then.

The Jet Propulsion Laboratory maintains NASA’s Deep Space Network. JPL maintains DSN from over 3 facilities around Earth, which are 120 degrees apart from longitude to enable more coverage and to maintain constant communication when the planet rotates. This also allows NASA to have radar and radio astronomy observations.

Radio antennas 

To answer the first question, during the Apollo 11 mission, NASA used 14 antennas and a couple other methods here on earth and utilized  the S-Band to communicate with the space shuttle. S-Band stands for the frequency range between 2-4GHz range. In 2022, we even use the same S-Band for Wi-Fi, TV Signals, Mobile Services and Satellite communications.

When it comes to communication or data transfer, higher frequency means higher bandwidth. In 1980’s and 1990’s NASA adopted the X-Band for their Deep Space Network communications. X-Bands hold 8-10GHz range dealing with more bandwidth. In 2000’s they adopted the Ka-Band ranging in 26.5-40GHz. It is expected that the Deep Space Network will support optical communications in infrared frequencies in the near future.

Since signals have to travel long distances before reaching the earth, there is a good chance that cosmic noise will interfere with the signals. Cosmic noise is generated from literally anything in space; Suns, planets and their atmospheres, asteroids, interstellar gasses and also but not limited to dark matter. To have an acceptable reception, the Jet Propulsion Laboratory uses large antennas with precise antenna pointing, sensitive receivers, cryogenically cooled low-noise amplifiers and computer algorithms for error correction.

Chanuka Bandara