Yesterday (Friday 7th of May) NASA released recorded sound of its Ingenuity helicopter, during its fourth Mars flight on the 30th of April!
We have honestly lost count of the number of firsts in the Perseverance/Ingenuity Mars mission. First, we saw video of a Mars landing, for the first time. We heard the winds in Mars’ thin atmosphere. Then of course came the helicopter, making flight after flight. And now, NASA is presenting us with sound it recorded, of the whirring rotors of a helicopter on another world!
With atmosphere as thin as that on Mars, sound can’t travel great distances easily. Plus, there is quite a bit of background noise, from the winds on the planet. At the time that NASA recorded its sound, the Ingenuity helicopter was 262 feet (80 metres) away from Perseverance.
Of course the helicopter sound that NASA recorded has had to undergo some enhancement, to get what you hear here. But that we have it at all, is impressive enough. The mission’s own team didn’t know if capturing this audio would actually work. The team behind the design of the microphone thought that the sound would only barely register!
And actually, the microphone that NASA used to capture this sound, had nothing to do with the helicopter mission. This mission’s assortment of cool facts continues with the actual purpose of this microphone, that rivals the helicopter. It has to do with a laser. The kind of laser that zaps things – in this case, rocks!
How NASA Recorded The Sound Of The Helicopter
The device in question is the ‘SuperCam’ laser instrument. And it really works by zapping rocks from a distance. Meanwhile, its spectrometer studies the chemical composition of the vapour, and a microphone records the sound of the strike. The sound reveals information about the properties of the target. It is this microphone that NASA used, to record the helicopter’s sound!
Now, if you’re expecting whirring helicopter noises, like that of the Hueys in Apocalypse Now, you will be disappointed. The blades of this incredible flying machine spin at 2,537 rpm. In this atmosphere, NASA’s recorded result is a deep sound, unlike any helicopter – or drone. The frequency is at around 84 Hertz. Perhaps the low frequency helped the sound travel a bit farther?
We don’t know if the mission team is planning any flights that would bring the helicopter closer to Perseverance. But increasing its collection of helicopter sounds on Mars, is likely a very low priority for NASA! As we saw recently, the mission is now switching focus to Perseverance itself and its other instruments.
But Ingenuity absolutely proved its worth! So NASA will switch its focus from “mere” testing of Mars flight, to operational usage. It will be interesting to see what results this new mission will have.
Until these results come, you can listen to the helicopter sound that NASA recorded, below! Headphones might work better than speakers.