The space agency on Friday released new footage shot by the six-wheeled robot of its rotorcraft mate making its fourth flight on April 30 – this time accompanied by an audio track.
The nearly three-minute video begins with the low rumble of the wind blowing over Jezero Crater, where Perseverance landed in February on a mission to search for signs of ancient microbes.
The ingenuity takes off and its blades can be heard humming softly as they spin at nearly 2,400 rpm on the 262-meter (872-foot) round trip.
Mission engineers were unsure of picking up the flight noise, as Perseverance was parked 80 meters (262 feet) from the take-off and landing point.
The Martian atmosphere is about one percent of the density of our planet, which makes everything much quieter than on Earth.
“It’s a very good surprise,” said David Mimoun, professor of planetary science at the Institut Supérieur de l’Aéronautique et de l’Espace (ISAE-SUPAERO) in Toulouse, France, and chief scientist for the SuperCam microphone. March.
“We had performed tests and simulations which told us that the microphone would hardly pick up the sounds of the helicopter, because the atmosphere of Mars strongly dampens the propagation of sound,” he added.
The SuperCam is an instrument onboard Perseverance that laser zaps rocks from a distance to study their vapor with a device called a spectrometer that reveals their chemical composition.
It also comes with a microphone to record sounds, which gives additional information about the physical properties of targets, like their hardness.
Likewise, Mimoun explained, Ingenuity’s new flight recording “will be a gold mine for our understanding of the Martian atmosphere.” In addition to having a lower volume, sounds emitted on Mars travel more slowly than on Earth, due to the cold temperatures, which average -81 degrees Fahrenheit (-63 degrees Celsius) at the surface.
The speed of sound on the planet is therefore around 540 mph (around 240 meters per second), compared to around 760 mph (around 340 meters per second) here.
Mars’ atmosphere, which is 96% carbon dioxide, tends to absorb high-pitched sounds, so only lower-pitched sounds can travel long distances.
NASA improved the audio, which was recorded in mono, by isolating the pitch of the helicopter’s blades at 84 hertz and reducing the audio at frequencies below 80 and above 90 hertz. They then increased the volume of the remaining signal.
Soren Madsen, head of Perseverance payload development at NASA’s Jet Propulsion Laboratory, said the recording was an example of how mission instruments can work in tandem to improve our understanding of the Red Planet.
As ingenuity moves away from perseverance and shooting, the height decreases, and as it returns, the height increases.
This is known as the Doppler effect and provides an additional layer of confirmation of the helicopter’s flight path when it is out of visual range.
Posted in Dawn on May 9, 2021