Drone

Drones are aerial vehicles that operate on Batteries by flying between selected Drone Ports.

Usage
Each Drone can only be assigned to 1 home Drone Port, and that home Drone Port can only be linked to 1 other Drone Port (that Drone Port, in turn, doesn't necessarily need to be linked back to this Drone Port). There is no limitation on the numbers of assigned Drones unloading on a Drone Port, however one must be queued until the other fully unloads. Waiting Drones will circle above the Drone Port.

When flying from one Port to another, a Drone will show a take-off animation, wiggling around, rise vertically, turning mid-air then fly roughly in a straight line to the destination, then descends, followed by some wiggling animation and finally docks. Drones will attempt to navigate around obstacles mid-flight. As the take-off and landing can take up a considerable amount of time, the efficiency of Drones increases with distance.

A Drone consumes a minimum of 4 Batteries per trip plus 1 Battery per km of flight distance.

Drones are potentially the 2nd fastest mean of transportation, second to the Hyper Tube cannon. Pioneers can stand on the Drone for a ride, however, a fall protection equipment such as a Jetpack is highly recommended as the Drone will push away the pioneer mid-air when it starts accelerating forward.

Logistics
Drones can be used for long-range low-throughput transportation, such as of high-end products, which usually come in small per-minute quantities. Drones can only transport between two Drone Ports, the home Port and any other Port. At least one of the Drone Ports requires a steady supply of Batteries to power the Drone(s). Unlike trains, Drones don't block the input of items during the cargo loading animation.

Behavior
Drones will try to fly from Drone Ports to other Drone Ports as straight as possible. When terrain is in the path, the Drone will try to avoid the object. To path, Drones uses a 64 x 64 grid of the world to generate their path.

Drones have only one home Port, which is the Port the Drone is built on. No more additional Drones can be build onto a Drone Port, but multiple Drones can serve it as their destination Port. If multiple Drones are awaiting to be unloaded at the same time, they will fly around the Port at a 20m radius, stacking vertically with an 8m gap in between.

A Drone will initially take the required amount of batteries for a round trip from its home Port, consuming the Batteries immediately upon takeoff. If the Drone is being supplied with Batteries in its destination (non-home) Port instead, it will take the requried amount of batteries for a round trip, but not consume them until it returns to its home Port and takes off from it, taking no Batteries from the home Port. In this scenario, it has to be manually supplied with Batteries from the home Port for its first trip, as it would not take off from the home Port to start transporting otherwise.

Efficiency
After the first round trip is finished, the stack throughput of the Drone will be shown in the Drone's home Port, alongside its maximum throughput and Batteries required per round trip. The efficiency of Drones increases with travel distance, as the landing and take-off animation takes 51 seconds. If the route is too short, most of it will be the landing animations; it would take 102 seconds to move items from two Drone Ports immediately next to each other.

Trivia

 * The development of Drones was vaguely alluded to on May 15th, 2020: "There's going to be a new vehicle in Tier 7 or 8".
 * The inclusion of Drones was jokingly "confirmed" on July 23rd, 2020, via Jace's high quality screenshots/mspaint art video.
 * During Update 5 and some of Update 6, the drones used the spirit of the portable miner in their recipe to drill straight under the ground, ignoring the world grid and flying under the map. This was fixed during Update 6's Experimental Period.
 * The drones have a theoretically unlimited queue for the holding pattern on drone ports if the port is unpowered and can remain in the air in the holding pattern for a extremely long time

History

 * Patch 0.4.0.11: Reduced default round-trip Battery cost for Drones to 4 (from 5) and reduced cost/distance from 1.66 to 1 Battery per kilometre.
 * Patch 0.4.0.10: Fixed bug where the distance between Drone stations wouldn’t be calculated properly, causing incorrect round-trip time estimates and battery consumption, Battery consumption should now properly increase over larger distances.
 * Patch 0.4.0.6:
 * Drone Pathfinding and World Grid improvements. Drones will now fly to the closest cell if trying to pathfind outside of the grid instead of crashing. Building outside of the grid might have some weird behaviour but shouldn’t cause crashes anymore
 * Removed an ensure that caused many crashes when loading a big save
 * Fixed a bug where Drones would skip a station if saving when it’s docking, causing it to take off and bring the items back again when loading
 * Patch 0.4.0.4:
 * Potential fix for a scenario where the Drones would take a nonsensical path to their destination
 * Fixed a bug where Drones would teleport when dismantling a Drone Station they are about to dock on
 * Fixed a rare crash related to Drones
 * Fixed Drone Ports allowing duplicate names
 * Patch 0.4.0.0: Introduced