Space – NASA’s Mars helicopter will soon attempt something for the first time
NASA’s Chief Pilot for its Mars helicopter named Ingenuity has said that flights on the Red Planet are getting harder and harder.
Chief Pilot Havard Grip has written on NASA’s website about the recent difficulties the Ingenuity team is facing with launches. Grip explains that due to Mars’ seasonal variations drop, researchers are recording a drop in atmospheric density in the Jezero Crater where Ingenuity is located. While the drop seems significant when looking at in terms of numbers, Grip says that it has a major impact on Ingenuity’s ability to fly.
Don’t rule out NASA scientists just yet, as they do have a plan to combat this issue of atmospheric density. Grip says, “We will begin by performing a high-speed spin of the rotor without leaving the ground, reaching a peak rotor speed of 2,800 rpm (more than a 10% increase relative to our prior Mars experience of 2,537 rpm). If all goes well, we will follow this with a short test flight at a slightly lower rotor speed of 2,700 rpm. This would be our 14th flight.“
Additionally, Grip writes that the Ingenuity team will be spinning Ingenuity’s rotors faster than they have ever been spun before. “In fact, they will have to spin faster than we have ever attempted with Ingenuity or any of our test helicopters on Earth. This is not something we take lightly, which is why our next operations on Mars will be focused on carefully testing out higher rotor speeds in preparation for future flights.“
Grip explains why Ingenuity flights are becoming harder and harder;
When we designed and tested Ingenuity on Earth, we expected Ingenuity’s five-flight mission to be completed within the first few months after Perseverance’s landing in February 2021. We therefore prepared for flights at atmospheric densities between 0.0145 and 0.0185 kg/m3, which is equivalent to 1.2-1.5% of Earth’s atmospheric density at sea level. With Ingenuity in its sixth month of operation, however, we have entered a season where the densities in Jezero Crater are dropping to even lower levels. In the coming months we may see densities as low as 0.012 kg/m3 (1.0% of Earth’s density) during the afternoon hours that are preferable for flight.
The difference may seem small, but it has a significant impact on Ingenuity’s ability to fly. At our lower design limit for atmospheric density (0.0145 kg/m3), we know that Ingenuity has a thrust margin of at least 30%. Thrust margin refers to the excess thrust that Ingenuity can produce above and beyond what is required to hover. That additional thrust is needed on takeoffs and climbs, during maneuvers, and also when tracking terrain with varying height. But if the atmospheric density were to drop to 0.012 kg/m3 in the coming months, our helicopter’s thrust margin could drop to as low as 8%, which means that Ingenuity would be operating close to aerodynamic stall (a condition where further increases in the blade’s angle of attack does not produce more lift, only more drag).
If you are interested in reading more about NASA’s next upcoming flight with Ingenuity, check out this link here.