- "A meter-tall stack of the worst business decisions you could possibly want."
- ―Mechtech Illustrated, criticizing the R5-series
The R5-series astromech droid was a line of low-cost astromech droids built by Industrial Automaton. Based upon the success of prior astromech models, such as the wildly popular R2-series, Industrial Automaton intended the R5-series to cater to budget buyers at the cost of some functionality.
Because of their inexpensive construction, however, droids of this series were plagued by a number of design flaws—most obviously, a sullen demeanor and sharp attitude resulting from deficiencies in the machine's personality matrix. Media outlets soon picked up on these errors: Mechtech Illustrated called the R5 model "a meter-tall stack of the worst business decisions you could possibly want."
After a particularly poor sales year, Industrial Automaton discontinued the R5 series in 22 BBY. To cover losses, the droid manufacturing firm repackaged R2-AG-series and R4-series droids in excess R5 shells.
During the Clone Wars, members of the R5-series were used by the Republic for a variety of roles, including use aboard starfighters like the ARC-170 and capital ships like the Acclamator-class assault ship.
One R5 unit in particular, R5-D4 was almost sold to Luke Skywalker by Jawas on Tatooine, but was exchanged for R2-D2, following a catastrophic failure of its motivator.
They were less commonly used by Rebel pilots because the extra height of the R5 made them a more prominent target in an X-wing's droid socket, although the Alliance used them in maintenance jobs extensively due to their low cost and the Alliance's desperate need for functional droids of any kind. Rebel technicians also upgraded some R5 units for starfighter use, bringing their astrogation capabilities up to the level of the R2-series, though the personality flaws persisted. Wedge Antilles used an R5 model with the designation of R5-D2, nicknamed "Mynock." The droid was upgraded and redesignated R5-G8 after a memory wipe, and Antilles changed its nickname to "Gate." When first assigned the droid, Antilles judged its slightly larger target profile to actually be an advantage, as it might block a laser that would otherwise reach the cockpit.
Due to their design problems, a number of R5 units were part of the population of ownerless, unwanted, and otherwise abandoned droids inhabiting Kligson's Moon.