R2-Delta
this was the name of an upgrade which was developed for use on R2-series astromech droids twenty years after the Battle of Endor. It involved new algorithms and programming to speed up the calculation of navigational data, shortening the time it took to develop a hyperspace jump. This allowed many owners of R2 units - especially large military concerns like the New Republic - to get many more years of service out of their large pool of R2 droids.