The USS Lagrange (NCC-3916) was a Ptolemy-class transport/tug active in the 23rd century. (Star Fleet Technical Manual) Throughout much of its operational lifetime, Lagrange was assigned to the Starfleet First Fleet. In the mid-2280s, Lagrange, USS Constellation II and USS Polaris were the mainstays of the First Fleet Carrier Group. (Starfleet Communiqué 19) Lagrange was operating in Quadrant 0 as a free-flying command post in February 2288. (Star Trek: Avenger: "As Others See Us")