Wednesday, November 22, 2023

Me? I'm Still Waiting For A "St. Elmo's Fire" Generating Flight On Mars... Heh.


NASA is learning lots of new low pressure atmosphere / chopper flying tricks, out 41 million miles into the night sky.

Below is the latest, but simple physics in that low pressure environment would suggest that if the copter is flown at high RPMs, at sunset -- we ought to see a very noticeable blue green glow -- St. Elmo's Fire.

That image is at right, with my old story on that possibility here, from February 2022.

But here is NASA's latest on chopper flying -- off world, on Barsoom:

. . .Over the past nine months, we have doubled our max airspeed and altitude, increased our rate of vertical and horizontal acceleration, and even learned to land slower,” said Travis Brown, Ingenuity’s chief engineer at JPL. “The envelope expansion provides invaluable data that can be used by mission designers for future Mars helicopters.”

Limited by available energy and motor-temperature considerations, Ingenuity flights usually last around two to three minutes. Although the helicopter can cover more ground in a single flight by flying faster, flying too fast can confuse the onboard navigation system. The system uses a camera that recognizes rocks and other surface features as they move through its field of view. If those features whiz by too fast, the system can lose its way.

So, to achieve a higher maximum ground speed, the team sends commands for Ingenuity to fly at higher altitudes (instructions are sent to the helicopter before each flight), which keeps features in view longer. Flight 61 established a new altitude record of 78.7 feet (24 meters) as it checked out Martian wind patterns. With Flight 62 Ingenuity set a speed record of 22.3 mph (10 meters per second) -- and scouted a location for the Perseverance rover’s science team.

The team has also been experimenting with Ingenuity’s landing speed. The helicopter was designed to contact the surface at a relatively brisk 2.2 mph (1 mps) so its onboard sensors could easily confirm touchdown and shut down the rotors before it could bounce back into the air. A helicopter that lands more slowly could be designed with lighter landing gear. So, on Flights 57, 58, and 59 they gave it a whirl, demonstrating Ingenuity could land at speeds 25% slower than the helicopter was originally designed to land at.

All this Martian Chuck Yeager-ing is not over. [Ed. Note: Glad to hear it! We have some. . . suggestions (see first paragraph)!] In December, after solar conjunction, Ingenuity is expected to perform two high-speed flights during which it will execute a special set of pitch-and-roll angles designed to measure its performance.

“The data will be extremely useful in fine-tuning our aero-mechanical models of how rotorcraft behave on Mars,” said Brown. . . .


The footage would be. . . amazing!

Okay -- likely falling silent now, until Friday -- with so many pots boilin' all at once here through late afternoon tomorrow. . . smile.

नमस्ते

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