A regenerable carbon dioxide (CO2) removal system has demonstrated its capability for Extended Duration Orbiter (EDO) missions during Shuttle Columbia flights STS-50, STS-52 and STS-55. The EDO requirements of missions up to 18 days and the capability for future missions up to 30 days necessitated the development and implementation of the regenerable CO2 removal system. The designed system offers a substantial weight and stowage volume reduction for missions beyond eight (8) days as compared to the baseline, nonregenerable, Lithium Hydroxide (LiOH) CO2 removal unit. 1 The system, referred to as the Regenerable CO2 Removal System (RCRS) was designed and developed by Hamilton Standard Division of United Technologies Corporation under contract to Rockwell International and NASA-Johnson Space Center.This paper presents an overview of the design characteristics and system performance. It includes the results from the development and qualification testing conducted at Hamilton Standard from November 1991 to February 1992, manned and unmanned testing conducted at NASA-JSC between March and April 1992 and the system's first three (3) Orbiter flights (STS-50, STS-52 and STS-55) in July and October 1992 and April 1993. During the first and third flights (STS-50, STS-55) the RCRS provided CO2 removal for both the Orbiter cabin and Spacelab.