An instrument sterile adapter for coupling a surgical instrument and an instrument carriage and for defining a sterile interface between the surgical instrument and the instrument carriage, the instrument sterile adapter comprising: a first portion comprising an adapter control surface and a carriage engaging surface opposite the adapter control surface; couplers connected to the first portion; and a second portion coupled to the first portion and comprising a convex curved surface; wherein the instrument sterile adapter is configured to receive the surgical instrument mounted thereto and, in a mounted state of the surgical instrument, the adapter control surface abuts an instrument control surface of the surgical instrument; wherein the instrument sterile adapter is configured to be mounted to the instrument carriage and, in a mounted state of the instrument sterile adapter, the carriage engaging surface abuts a carriage control surface of the instrument carriage; wherein, in the mounted state of the instrument sterile adapter to the instrument carriage and the mounted state of the surgical instrument to the instrument sterile adapter, the couplers engage carriage control features of the carriage control surface and instrument control features of the instrument control surface such that motion of the carriage control features is transferred to the instrument control features via the couplers; wherein the convex curved surface is coupled to the adapter control surface with the convex curved surface substantially perpendicular to and facing the adapter control surface and being convex from a perspective at the adapter control surface; and wherein the convex curved surface is configured to, as the surgical instrument is mounted to the instrument sterile adapter, receive a corresponding concave curved surface of the surgical instrument extending from the instrument control surface. a first portion comprising an adapter control surface and a carriage engaging surface opposite the adapter control surface; couplers connected to the first portion; and a second portion coupled to the first portion and comprising a convex curved surface; wherein the instrument sterile adapter is configured to receive the surgical instrument mounted thereto and, in a mounted state of the surgical instrument, the adapter control surface abuts an instrument control surface of the surgical instrument; wherein the instrument sterile adapter is configured to be mounted to the instrument carriage and, in a mounted state of the instrument sterile adapter, the carriage engaging surface abuts a carriage control surface of the instrument carriage; wherein, in the mounted state of the instrument sterile adapter to the instrument carriage and the mounted state of the surgical instrument to the instrument sterile adapter, the couplers engage carriage control features of the carriage control surface and instrument control features of the instrument control surface such that motion of the carriage control features is transferred to the instrument control features via the couplers; wherein the convex curved surface is coupled to the adapter control surface with the convex curved surface substantially perpendicular to and facing the adapter control surface and being convex from a perspective at the adapter control surface; and wherein the convex curved surface is configured to, as the surgical instrument is mounted to the instrument sterile adapter, receive a corresponding concave curved surface of the surgical instrument extending from the instrument control surface.