An aerospace vehicle system, comprising: an external air supply device operative to selectively provide external air into the interior volume of an aerospace vehicle having an interior volume comprising at least a first interior volume portion and a second interior volume portion; a recirculation device operative to selectively move air between the first and second interior volume portions of the interior volume; a regenerative gas contaminant filter operative to remove gas contaminants from air; a plurality of bypass valves (20, 42, 46), each operative to selectively direct some or all of an airflow directed through the bypass valve (20, 42, 46) either into or around a downstream component (22, 44, 48); air quality sensors (18, 24, 40, 50); and a controller operatively connected to the external air supply device, recirculation device, regenerative gas contaminant filter, bypass valves (20, 42, 46), and air quality sensors (18, 24, 40, 50), and operative to control one or more of the external air supply device, recirculation device, regenerative gas contaminant filter, and bypass valves (20, 42, 46) in response to air quality deduced from the air quality sensors (18, 24, 40, 50), wherein the controller is operative to control an amount of recirculated air routed through the regenerative gas contaminant filter in response to air quality deduced from the air quality sensors (40, 50); and wherein said air quality sensors (40, 50) comprise an upstream air quality sensor upstream of the regenerative gas contaminant filter and a downstream air quality sensor downstream of the regenerative gas contaminant filter, and wherein the controller is operative to cause the regenerative gas contaminant filter to regenerate by removing contaminants in response to a difference in air quality deduced from comparing outputs of the upstream and downstream air quality sensors (40, 50), wherein the controller is operative to cause the regenerative gas contaminant filter to remove contaminants during regeneration by applying air at a temperature of at least 65.6 °C (140° F) to a sorbent used by the regenerative gas contaminant filter. an external air supply device operative to selectively provide external air into the interior volume of an aerospace vehicle having an interior volume comprising at least a first interior volume portion and a second interior volume portion; a recirculation device operative to selectively move air between the first and second interior volume portions of the interior volume; a regenerative gas contaminant filter operative to remove gas contaminants from air; a plurality of bypass valves (20, 42, 46), each operative to selectively direct some or all of an airflow directed through the bypass valve (20, 42, 46) either into or around a downstream component (22, 44, 48); air quality sensors (18, 24, 40, 50); and a controller operatively connected to the external air supply device, recirculation device, regenerative gas contaminant filter, bypass valves (20, 42, 46), and air quality sensors (18, 24, 40, 50), and operative to control one or more of the external air supply device, recirculation device, regenerative gas contaminant filter, and bypass valves (20, 42, 46) in response to air quality deduced from the air quality sensors (18, 24, 40, 50), wherein the controller is operative to control an amount of recirculated air routed through the regenerative gas contaminant filter in response to air quality deduced from the air quality sensors (40, 50); and wherein said air quality sensors (40, 50) comprise an upstream air quality sensor upstream of the regenerative gas contaminant filter and a downstream air quality sensor downstream of the regenerative gas contaminant filter, and wherein the controller is operative to cause the regenerative gas contaminant filter to regenerate by removing contaminants in response to a difference in air quality deduced from comparing outputs of the upstream and downstream air quality sensors (40, 50), wherein the controller is operative to cause the regenerative gas contaminant filter to remove contaminants during regeneration by applying air at a temperature of at least 65.6 °C (140° F) to a sorbent used by the regenerative gas contaminant filter.