Perseverance is the latest plucky Mars rover winging its way to the Red Planet, but it has some tricks up its sleeves that no other rover has managed before. Perseverance comes armed with microphones, which means it can document its travel to Mars like no other, and now NASA has released some of the sounds recorded by the spacecraft as it hurtles its way through deep space.
The other microphone is located in the rover's Entry, Descent and Landing (EDL) system, designed to record its, you guessed it, entry, descent, and landing. Again, if all goes as it should, the mic should pick up everything from the sound of the mortar releasing the parachute, to the landing engines, to the sound of the rover's wheels crunching on the Martian gravel.
During an in-flight check of the camera and microphone equipment on October 19, team members captured a 60-second audio file of the rover's inner workings, a subtle whir, as it whizzed through space.
"With apologies to the person who came up with the slogan for Alien, I guess you could say that in space no one may be able to hear you scream, but they can hear your heat rejection fluid pump," said Dave Gruel, lead engineer for the mission's EDL system. "The microphone we included to hear what it's like to land on Mars was actually able to pick up Perseverance's thermal system operating in the vacuum of space through mechanical vibration."
Of course, the sound waves did not travel through space for the mic to pick up. We think of sound as something that makes noise, but in physics terms, sound is just a vibration going through matter. In this case, the vibrations traveling through the rover itself were captured and turned into an electronic signal. The file was then processed by Danish company DPA Microphones, which manufactured the EDL hardware for the mission.
As fun as it is to hear the sound of a rover flying through space, the equipment check has vitally shown that the recording equipment works, and we have a lot more exciting sounds of Mars to look forward to.
"As great as it is to pick up a little audio on spacecraft operations in-flight, the sound file has a more important meaning," Gruel added. "It means that our system is working and ready to try to record some of the sound and fury of a Mars landing."
Despite previous efforts to send a microphone to Mars, this is the first time it's been successful. A similar design was onboard the Mars Polar Lander in the 1990s, but the spacecraft crashed on the surface and was lost. In 2008, one was attached to the Phoenix mission, but experienced electronics issues, so never worked. If Perseverance's "7 minutes of terror" goes ahead without a hitch, it's about to open up Mars to us in a way we've never experienced before.
