Today, Walmart and Zipline are announcing preliminary plans “to bring first-of-its kind drone delivery service to the United States.” What makes this drone-delivery service the first of its kind is that Zipline uses fixed-wing drones rather than rotorcraft, giving them a relatively large payload capacity and very long range at the cost of a significantly more complicated launch, landing, and delivery process. Zipline has made this work very well in Rwanda, and more recently in North Carolina. But expanding into commercial delivery to individual households is a much different challenge.
Along with a press release that doesn’t say much, Walmart and Zipline have released a short video of how they see the delivery operation happening, and it’s a little bit more, uh, optimistic than we’re entirely comfortable with.
Here’s the video:
And here’s all of the actually useful information from the one-page press release:
The new service will make on-demand deliveries of select health and wellness products with the potential to expand to general merchandise. Trial deliveries will take place near Walmart’s headquarters in Northwest Arkansas. Zipline will operate from a Walmart store and can service a 50-mile radius, which is about the size of the state of Connecticut. The operation will likely begin early next year, and, if successful, we’ll look to expand.
At first glance, there’s basic feasibility here, in the sense that most health and wellness products are likely to be of the size and weight to be transportable by one of Zipline’s drones—called Zips—and that a Zipline fulfillment center with a drone catapult and retrieval system could be set up to operate in a Walmart parking lot (or somewhere nearby) without any problems. However, drone delivery needs a lot more than basic feasibility to be successful—without more detail in the press release, we’ve had to look carefully at the video, and we’ve got some questions.
From the beginning of the video until about 20 seconds in, everything seems straightforward. A customer places an order, and a Zip is loaded and launched. Zipline has been doing this in Ghana and Rwanda for years, and we’ve seen firsthand how fast and efficient their operation is. It’s easy to see how this could translate into shipping items from a Walmart.
Our first question comes up at 22 seconds in, which shows a Zip flying along over a suburban or rural area a couple of hundred feet off the ground. Generally, this airspace is uncontrolled, meaning that other aircraft could be operating nearby. Zipline’s drones can detect other aircraft that are equipped with ADS-B transmitters, which covers an increasing number of manned aircraft. However, up to 400 feet of altitude, airspace is (with some exceptions) typically open to consumer drones as well, which usually do not have ADS-B transmitters. We know that Zipline is working on its own onboard sense and avoid system, but until they have that working, there’s a risk of a Zip colliding with another drone. The sky is big, so this may not be very likely, but it’s still something that should be taken into consideration. One way of mitigating this risk is by flying higher than 400 feet, but that starts getting into more complicated stuff with the U.S. Federal Aviation Administration. Zipline and Walmart are undoubtedly getting into complicated stuff with the FAA anyway, though, so maybe that’s the plan.
From 26 seconds to 30 seconds, we see what looks like the same kind of Zip delivery that we saw in Africa, so that’s cool. But between 31 and 35 seconds, the video shows exactly where that delivery happened: What appears to be a walkway up to a suburban house, in between a parked car, a porch, and the street. As far as we know, and based on what we’ve seen of Zips making deliveries, this kind of precision is simply not possible for a package on a parachute dropped from a fixed-wing drone.
While Zips do their best to make pinpoint deliveries, even going as far as compensating for wind whenever possible, you really need a circular-ish open area with a radius of perhaps 5 meters or so for the Zips to deliver to. And you wouldn’t really want to have something like a house adjacent to that, since there’d be some risk of a package landing on the roof. Being close to a road would be even worse, because you can imagine how a driver might react if a wayward box on a parachute landed on their windshield by surprise. Finally, since Zips descend to somewhere between 35 and 50 feet to release the package, you need a flight path across the delivery area that’s free of obstructions. Zips can drop packages from higher altitudes, of course, but if they do, the delivery area needs to be even larger.
We sent Zipline and Walmart some specific questions about what’s going on in the video and how the delivery process will actually work, and received the following response:
The video represents the vision for how the delivery service to Walmart customer homes will work. We’ll be happy to keep you posted on the technical aspects of the operation as we get closer to launching the trial.
We sent a follow-up email to Walmart asking for some clarification, but they weren’t able to share any additional detail on the record.
The issue I have with Walmart’s desire to show their vision is that I really don’t see how this vision could ever become a reality through Zipline, because as far as we’re aware Zipline’s parachute system fundamentally cannot achieve the porch-level precision that the video advertises. This is a big deal, because it places substantial constraints on where Walmart will be able to deliver to, and dense suburbs as shown in the video may realistically be off the table. What the video shows is more the sort of thing that most consumers probably associate with drone delivery because it’s been relentlessly promoted by companies like Google and Amazon, relying on the precision of rotorcraft. But that’s just not what Zipline does, and honestly, the fact that Zipline doesn’t do that stuff is one of the reasons that we think Zipline’s tech is uniquely useful.
Putting the video and the press release aside, let’s think about what Zipline and Walmart could realistically accomplish together. Assuming that “we’ll be happy to keep you posted on the technical aspects of the operation” actually means “we don’t have any easy answers to the questions that you asked” rather than “we have some amazing and secret new parachute steering technology* that will solve every problem,” what would Zips delivering stuff from Walmart actually look like?
The biggest issue here, I think, is making deliveries with fixed-wing drones dropping boxes on parachutes in relatively dense suburban neighborhoods. I just don’t see how that’s going to work in a safe and scalable way, and of course urban deliveries would be even worse. But that’s totally fine—in high density areas, other delivery systems already exist and can operate efficiently. There are legacy delivery systems (like humans moving stuff in trucks) and gig workers, as well as new technologies like sidewalk robots, autonomous vehicles, or hybrid systems. In order for these delivery systems to make sense, though, there needs to be a certain density of customers, such that the balance of time making deliveries versus time spent getting from one place to another works out in your favor. Otherwise, your delivery system is hard to make sustainable.
What this means is that if you live in a rural area, your options for on-demand delivery are much more limited, which is part of the reason that Zipline exists in the first place: It excels in fast, efficient deliveries to isolated locations that are a substantial distance away. They do this kind of delivery better than anyone else, and rural delivery is a niche that rotorcraft or sidewalk robots or whatever just can’t compete in. Furthermore, for many people who live in rural areas, this kind of delivery would be incredibly valuable because options are so limited. For Zipline, the great thing about focusing on rural rather than suburban delivery is that delivery becomes much less complicated. People are more spread out, and it’s more likely that more homes will have backyards that can easily support a Zip parachute delivery. It really seems like rural areas, rather than suburbs, is where a Zipline Walmart partnership would have the most value, at least if Zipline is not going to somehow significantly alter its operation.
In the past, I’ve been super skeptical of urban (and to a lesser extent, suburban) delivery drones. I still am, primarily because I’m not convinced that the risk and expense of using drones to deliver things is worth it, relative to already established delivery systems or new delivery systems (like ground robots) that operate more conventionally. But rural delivery is different, and Zipline has shown that they can do it quickly and efficiently. So much of drone delivery really seems like it’s just companies reacting to the positive press that they inevitably get, combined with consumers asserting that it’s something they want without really thinking about whether it’s something that will make a tangible difference to their lives. For someone who lives far away from the nearest Walmart, though, being able to order and receive something like medicine in an hour without having to leave their yard could make a difference in a way that only Zipline can, at this point, deliver on.
*I desperately want this to be the case