Ingenuity- Mars 2020 Helicopter, Deployment & Operations Options

[Art Martin]

I'm putting this in the Early Drives category because I believe that one of the primary purposes of these first drives is to find a spot for the helicopter.

Is anyone else wondering like I am just what the terrain needs to look like to set the helicopter down? It sure looks to me that the areas we're in right now are largely free of obstacles for flying and landing with no large rocks. Unless you go for some completely sand covered spot I'm not sure you're going to find any areas any more pristine. Does anybody have any info about what type of zone they are exactly looking for? Since the helicopter is not really designed to be used for investigation of terrain but more as just a proof of concept of flight, I would imagine the choice of area would be wide open and flat.

Here's what I've got so far about upcoming events.

1. The helicopter below the rover limits ground clearance so it is vital that the helicopter phase be early in the drives so the rover is not limited in mobility.

2. The main purpose of the helicopter is proof of concept of Mars flight so the emphasis is not using it for exploration/route planning/research photography but merely that we can sustain flight - take off, fly autonomously, and land safely.

3. Once deposited on the surface, it will take a number of days of check outs prior to the first real flight.

Should we create a new topic that is discussion about the helicopter?

[PDP8E]

Mike is right, the missing rotor is off to the left of the 'copter
.... but...
I conjecture that the helicopter rotors spun into the sand ridge in the 'box' (the scars are there?)
and somehow, Ingenuity corkscrewed over to the nearer ridge and "stuck the landing", minus a rotor that flew off between the ridges (left).

The Route Map gurus could probably give us the distance/height.



... as always, I could be wrong...

[mcaplinger]

I conjecture that the helicopter rotors spun into the sand ridge in the 'box' (the scars are there?) and somehow, Ingenuity corkscrewed over to the nearer ridge...

Those marks look unrelated to me. The simplest explanation is that the heli flew into the ground at an angle ("CFIT") and broke the blades, but the landing gear stance was large enough and the CG low enough that the usual tipover was avoided and it stayed upright while the rotors spun down. There's no need to invoke more complex gymnastics IMHO.

[serpens]

Those marks look unrelated to me. The simplest explanation is that the heli flew into the ground at an angle ("CFIT") and broke the blades,.....

Yes, the blade end position and nearby impact mark indicate a straight line to Ingenuity's position. But the actual impact sequence is less clear. There seem to be two blade collision points (upper and lower?) and the left side of the solar panel is pushed down 90 degrees. Hard to see anything but a strike by an upper blade segment causing that and Tau's image seems to reveal only the inner section of the blade. Carbon fibre is strong and light but the blade tip speed is around 240mps and the velocity squared dominates in kinetic energy. I may be missing something but the impact outcomes on the blade seem complex, possibly a bend fracture then break at both the bend and the blade root, all at an impressive rotational velocity. Is there a missing part of the blade hiding somewhere?

[Bill Harris]

Yes, the blade end position and nearby impact mark indicate a straight line to Ingenuity's position. But the actual impact sequence is less clear. There seem to be two blade collision points (upper and lower?) and the left side of the solar panel is pushed down 90 degrees. Hard to see anything but a strike by an upper blade segment causing that and Tau's image seems to reveal only the inner section of the blade. Carbon fibre is strong and light but the blade tip speed is around 240mps and the velocity squared dominates in kinetic energy. I may be missing something but the impact outcomes on the blade seem complex, possibly a bend fracture then break at both the bend and the blade root, all at an impressive rotational velocity. Is there a missing part of the blade hiding somewhere?

It can be hard to say or visualize what a copter blade will do when impacting soft substrate at a low angle.
Ginny is down for the count but led a most excellent technology demonstration.

--Bill

[rlorenz]

It can be hard to say or visualize what a copter blade will do when impacting soft substrate at a low angle.

The interaction of the striking blade tip with the sand ripple, and its direct local effects on a composite structure, are indeed not well-constrained.

However, I suspect it is the other blade of that rotor that broke and was flung away. You can see this happen on lots of youtube videos of helicopter crashes, notably those where the blades hit water. The sudden angular deceleration of the rotor causes a huge bending moment at the root of the other blades, which feel strong compulsion from Newton's First Law.......