Gijsbert Tan

The FAE Electrolyser Flight Experiment FAVORITE: Current Development Status and Outlook

At the 2002 ICES, FAVORITE, the orbital flight experiment for a fixed alkaline electrolyte (FAE) electrolyser stack was presented. The planning at that time was to fly the experiment in September 2003 on board the SpaceHab mission STS-118 with the space shuttle COLUMBIA flight ISS-13A.1. Due to the tragic accident of COLUMBIA on Feb. 1st, 2003, these plans became obsolete and alternative launch opportunities were looked for. They were finally found with the unmanned Russian FOTON-M2, which is built by TsSKB-PROGRESS in Samara, Russia and scheduled for launch from the Baikonur cosmodrome in April 2005. Because of the switch from a manned to an unmanned mission and other operational constraints, FAVORITE had to be redesigned in several parts. This paper summarizes the objectives of the flight experiment and describes the required design changes. It also presents an overview of the actual development status as well as of the work ahead.

Results of Breadboard Tests Withan Integrated CO2, Humidity and Thermal Control System

Membrane gas absorption and desorption (MGA/MGD) for the removal of CO 2 in manned spacecraft or other enclosed environment is subject of study by Stork and TNO for many years. The system is based on the combination of membrane separation and gas absorption. Advantage of this technology is that the system not only can be used to remove the carbon dioxide but also to control the relative humidity and temperature. Absorption of moisture and heat is achieved by cooling the absorption liquid below the dewpoint temperature of the gas stream. From the start in 1995, the Crew Transfer Vehicle is used as a basis for the design (1,2). Compared to the planned air conditioning system, consisting of a condensing heat exchanger, LiOH cartridges and a water evaporator assembly, MGA/MGD shows advantage in volume, mass and power consumption. The absorption liquid circulates through the spacecraft thermal control loop, replacing the coolant water. The CO2 absorption capacity of the absorption liquid is restored in a desorption unit. This process is based on pervaporation. The absorption liquid is led through this membrane unit in which a reduced pressure is maintained using the space vacuum. Due to this pressure difference a driving force for water vapor and CO2 is created. The water evaporation and the CO2 desorption rate are controlled by a throttle valve in the venting duct to the vacuum source. Because the absorption liquid is used as coolant, temperature increases, a driving force for water vapor and CO2 mass transfer is created. Should additional heat rejection be required (off nominal case), it is established by dumping extra water, using the associated heat of vaporization. For the initial studies an existing laboratory set-up has been applied for the practical work. In 1999 a project started on the development of a dedicated breadboard. In this paper, the test results of this breadboard assembly will be presented. Copyright