Madrid, 8 (Europe Press)
NASA’s Perseverance rover on Mars used one of its two microphones to listen to the Ingenuity helicopter as it flew in the immediate vicinity for the fourth time on April 30th.
A new video clip (https://www.youtube.com/watch?v=y5niGi4k9vQ) combines helicopter images taken by Perseverance’s Mastcam-Z with sound from a microphone belonging to the rover’s SuperCam laser instrument.
The laser strikes rocks from a distance and studies its vapor with a spectrophotometer to reveal its chemical composition. The device’s microphone records the sounds of these lasers, which provide information about the targets’ physical properties, such as their relative hardness. The microphone can also record ambient noises, such as the winds of Mars
(https://soundcloud.com/nasa/listen-to-nasas-ingenuity-helicopter-as-it-flies-on-mars)
With persistence standing 80 meters from the helicopter takeoff and landing site, the rover mission was not sure if the microphone would pick up any sound from the flight. Even in flight, when the helicopter’s propellers rotate at 2,537 revolutions per minute, the sound is severely muffled by the thin atmosphere of Mars. It is even more obscured by the blowing of the Mars winds during the first moments of the flight. But despite everything, the drone can be heard above the wind.
“It’s a very good surprise,” said David Memon, professor of planetary science at the Higher Institute for Space (ISAE-SUPAERO) in Toulouse, France, and scientific director of the SuperCam Mars microphone. statement. “We did tests and simulations that told us that the microphone will hardly pick up the sounds from the helicopter, because the Martian atmosphere is dampened by the force of the sound propagation. We were lucky to record the helicopter at this distance. This recording would be a goldmine for our understanding of the Martian atmosphere.”
Doppler effect
Scientists have made the sound, recorded in mono, easier to hear by isolating the sound from the 84 Hz helicopter blade, reducing the frequencies to below 80 Hz and over 90 Hz, and increasing the size of the remaining signal. Some frequencies have been trimmed to highlight the helicopter’s hum, which is louder as the helicopter passes through the camera’s field of view.
“This is an example of how different arrays of payload instruments integrate with each other, resulting in information synergistic,” said Surin Madsen, director of persistent payload development at NASA’s Jet Propulsion Laboratory in Southern California. “In this particular case, the microphone and video allow us to monitor the helicopter as if we were there, and additional information, such as the Doppler effect, confirms the details of the flight path.”
