Inside Ingenuity With AeroVironment, Part One: Designing It

Inside Ingenuity With AeroVironment, Part One: Designing It

April 19th noticed what some have christened “a second Wright Brothers second”—particularly, the profitable first powered managed flight by an plane on one other world. Reaching Mars on the underside of the Perseverance rover, the tiny, autonomous Mars Ingenuity Helicopter (5.4’ x 7.7’ x 6.4”) spun its 4-foot rotors and hovered 10 toes off the bottom for 30 seconds. By its third flight, a couple of days later, Ingenuity would rise 16 toes (5 m) up, and fly 164 toes (50 meters) at a high velocity of 6.6 ft/sec (2 m/sec). Back in 1903, the Wright Brothers logged 120 toes to finish the primary managed heavier-than-air powered flight. Now, squaring that circle, Ingenuity carries a bit of material from the wing of the Wright Flyer, and its flight website is known as Wright Brothers Field.

One hundred seventy million miles later, Ingenuity was able to fly on Mars. Photo courtesy nasa.gov.

Ingenuity represents a end result of labor by, amongst others, NASA/JPL, a bevy of firms—and AeroVironment. For the key producer of unmanned techniques, the flight path to Mars started in 2013, and featured continued collaboration, particularly with rotorcraft consultants at NASA, and with JPL engineers within the electrical, mechanical, techniques and automobile flight management areas. AeroVironment designed and developed Ingenuity’s airframe and main subsystems, together with its rotor, rotor blades, and hub and management mechanism {hardware}. The Simi Valley, California-based firm additionally developed and constructed high-efficiency, light-weight propulsion motors, energy electronics, touchdown gear, load-bearing buildings and thermal enclosures for NASA/JPL’s avionics, sensors and software program techniques.

AeroVironment president and CEO Wahid Nawabi summed up his firm’s contribution: “AeroVironment’s deep, wealthy and various historical past of designing dependable and efficient unmanned options that ship mission success in excessive environments, mixed with our expertise with near-space plane, make us uniquely suited to collaborate with NASA and JPL. We additionally included the ultra-lightweight and ultra-high-precision strategies integral to Nano initiatives which have been developed in our MacCready Works Advance Solutions laboratory.”

Subsequent protection will embrace different firms’ developmental work. Here, an AeroVironment engineering crew will talk about key contributions to Ingenuity’s skill to fly on a planet greater than 170 million miles and counting from earth in an environment 1% as thick as ours.

Comments have been edited and reordered for readability.

BEGINNINGS

Matt Keennon [AV’s technical lead for the rotor system development on the Mars Ingenuity Helicopter Program and an AeroVironment principal electrical engineer. Joined AeroVironment in 1996, and has worked mostly on micro/nano UAVs.]

AeroVironment began as an organization making pedal-powered airplanes, uncommon man-carrying airplanes, a Solar Challenger. When I got here on board in 1996, we had been creating small surveillance plane for the army, together with a flapping-wing plane. We did plenty of DARPA work and DARPA does the actually far-out tough issues, not figuring out essentially the place it’s going to go, what it will likely be used for. I used to be actually lucky to move up plenty of little initiatives that had been DARPA-funded, such because the Black Widow [the first micro air vehicle]. We additionally had the Hornet, which was our first gas cell-powered small automobile. And the Hummingbird was probably the most fantastical flying machine we may ever conceive of—and that was four-and-a-half years of banging our heads in opposition to the wall, attempting to determine that one out. That was sort of the premise for our bizarre and weird flying machines that appeared to swimsuit problem-solving for uncommon utility, uncommon necessities, actually tough buyer requests.

JPL requested us how can we exhibit flight in Mars simply, and once I got here on board, I introduced in my concepts from these different initiatives. And that’s why we did the sub-scale. And we additionally did this different one, which simply had a motor and rotor blades. It went up and down on rails, it truly regarded like the actual helicopter, but it surely’s simply principally an empty fuselage. But all of them labored, and served their goal of getting the joy and curiosity ranges raised to the following level of funding.

Ben Pipenberg [AV’s engineering lead on the Mars Ingenuity Helicopter Program and AeroVironment senior aeromechanical engineer; joined AV in 2014, worked on sub-scale, larger demonstrators and the final build.]

AeroVironment labored very briefly with JPL within the late Nineteen Nineties on some proposal efforts for a Mars helicopter; very imprecise, conceptual stuff that wasn’t funded on the time. But round 2012, 2013, the concept popped again up. The JPL chief engineer for this system got here again to AeroVironment and stated, “Hey, what do you consider serving to out with one thing like this?” That grew into some small-scale danger exams, primarily simply placing a rotor system right into a vacuum chamber representing a Martian ambiance, simply demonstrating that we will generate raise.

Early on, there was doubt, even inside NASA. With all these early exams, we’re attempting to determine what we don’t know, that we don’t know. There isn’t knowledge on the market that tells you ways that is going to work or what isn’t going to work proper. Coming up with exams which might be comparatively low cost and simple, and allowed to fail—that’s fairly essential.

OPERATIONAL REQUIREMENTS

Ben Pipenberg: Some conceptual designs for what the ultimate helicopter may seem like, they had been outlined as early as 2013. That [involved] a mix of parents, and AeroVironment was doing plenty of the airframe design. But the massive problem with a helicopter like that is that you simply’re not setting a helicopter on the floor of Mars after which flying it. You’re actually designing a small standalone spacecraft that additionally occurs to fly. Before we will ever get to the place we spin up the rotors and take off from the floor of Mars, an terrible lot that has to happen. And that basically defines what plenty of the automobile necessities are.

The environmental necessities had been straight from JPL. And that comes actually from the Mars 2020 mission: the Perseverance rover, mission, launch load necessities. The launch automobile—from an Atlas V, there’s a vibration spectrum we have now to outlive that defines many of the hundreds the helicopter is designed in opposition to. For controls, there are very particular necessities: pure frequency, rotor blades for hubs, touchdown gear and all of that flowed down from the JPL-GNC [guidance, navigation, control] crew. Sizing constraints was an enormous one—what the automobile goes to have to suit inside and unfold from, so there was plenty of work there. And that sort of went each methods, proper? AeroVironment saying, “Hey, that is what we’d like.” And, , Lockheed Martin [its Mars Helicopter Delivery System was designed to transport and deploy Ingenuity] and JPL working to accommodate that, and in addition us working to alter the automobile design to accommodate area out there. There was plenty of backwards and forwards on plenty of the surroundings units. Environmental necessities had been an enormous a part of it.

Matt Keennon: The wiring contained in the mast was sort of like a magic trick. It all needed to go in in a single piece after which department out and needed to be glued in place.

WEIRD AERIAL ROBOTICS

Ben Pipenberg: The first small-scale demonstrators that tried managed flight within the chamber [December 2014] had been comparatively uncontrollable.

Those preliminary small-scale helicopters had been primarily constructed the identical manner we’d construct a helicopter that flies right here on Earth. The downside we ended up having is that, primarily, in a Martian ambiance you might have these rotors spinning actually quick, you might have very low aerodynamic forces relative to the inertial forces within the rotor. And so the best way that the rotor system reacts to manage inputs may be very completely different. You even have a lot decrease aerodynamic damping. You can sort of consider it like this actually high-speed spinning flywheel you’re attempting to manage with very low aerodynamic forces, and there’s no damping. So whenever you see these items flying, they’re sort of far and wide, completely uncontrolled. We didn’t understand that originally, so after we realized that, then, “OK, the place do we have to put much more effort and time into the evaluation? Where is it actually going to be paying off for us?”

That was sort of when JPL took on all the avionics improvement, all of the steerage, navigation management, all of the simulation modeling. For probably the most half, they dealt with all of the batteries, charging photo voltaic array, all that. And AeroVironment took on the airframe, a rotor blade design propulsion motors, servo swashplates, the first construction.

Matt Keennon: Then we went to the full-size demonstrator, the chance discount, which was actually a lovely piece of engineering, That was the primary one which used the full-sized rotor blades. These had been all AeroVironment builds; the chance discount plane had the titanium components that JPL made.

Liftoff! Credit: NASA/JPL

SURVIVABILITY

Ben Pipenberg: In addition to all of these [space and Mars] environments, it has to outlive a check surroundings right here on Earth. That that’s the place by far probably the most working time is spent. Before we ever get to Mars, we’ve already gone by way of virtually the complete operational lifetime of the helicopter. We need to design for all of that. Flying on Mars is comparatively benign in comparison with launching on a rocket when it comes to automobile hundreds. The hub response forces in flight are very small in comparison with launching on the rocket. That’s actually the problem—you’re not simply designing this to fly on Mars, sadly; we’re attempting to design a really small, light-weight spacecraft that additionally occurs to fly.

ITERATIONS

Matt Keennon: A dozen ideas on paper had been by no means constructed. The first [built] one wasn’t actually a helicopter; it’s a field with a motor and rotors, however that was sort of the very first thing that regarded like a helicopter. And then for the subscale, there have been two variations that had barely completely different layouts, completely different passive stabilization techniques.

Then we went to the full-size plane. There was one model we known as the chance discount plane. And then we get into the place Ben is basically taking up the engineering design fashions.

Ben Pipenberg: After that first full-size helicopter, two engineering improvement fashions had been constructed. The intention there was that we’d begin to design what we’d name the flight mannequin, which is Ingenuity, a helicopter on Mars. Two engineering improvement fashions had been meant to be very comparable, that we’d be capable to check out. One was used for flight testing within the JPL 25-foot-wide area simulator. The different engineering improvement mannequin was used for environmental testing: thermal vacuum testing, launch hundreds, placing it on a shaker desk and vibrating it, attempting to simulate launch, in addition to shock testing, radiation and stuff like that. Those two helicopters had been functionally just like the flight automobile, and what we realized from these helicopters, we’d roll into the flight mannequin.

Matt Keennon: We additionally constructed one thing that regarded like a helicopter that was simply designed for testing the touchdown gear, the shock absorbers, the angles. We did all this in a movement seize room; it wasn’t a purposeful helicopter, but it surely was a purposeful prototype for testing the touchdown gear.

Ben Pipenberg: Representative mock-ups to check interfaces and deployments and issues like that. Various iterations of different subsystems. Not flyable helicopters, however used to check out flight life illustration, completely different subsystems.

At the top, all of it got here collectively. The airframe, the rotor system, the touchdown gear, all of that was mated to the avionics, the batteries, the photo voltaic array, which was an enormous crew effort. Solera developed the photo voltaic cells, we developed the construction they’re mounted on, and it was mated onto the rover by way of Lockheed Martin’s deployment system. An enormous crew effort. [Our] piece of it’s comparatively seen—plenty of the items you’ll be able to truly see whenever you have a look at an image of the helicopter, the touchdown gear that field on the underside and all of the mechanism and construction and rotor blades had been designed by AeroVironment.

That remaining flight mannequin, clearly, that’s sort of the Cadillac model. It had all the pieces constructed to actually survive on Mars.