Impact of low gravity on water electrolysis operation

Advanced space missions will require oxygen and hydrogen utilities for several important operations including the following: (1) propulsion; (2) electrical power generation and storage; (3) environmental control and life support; (4) extravehicular activity; (5) in-space manufacturing and (6) in-space science activities. An experiment suited to a Space Shuttle standard middeck payload has been designed for the Static Feed Water Electrolysis technology which has been viewed as being capable of efficient, reliable oxygen and hydrogen generation with few subsystem components. The program included: end use design requirements, phenomena to be studied, Space Shuttle Orbiter experiment constraints, experiment design and data requirements, and test hardware requirements. The objectives are to obtain scientific and engineering data for future research and development and to focus on demonstrating and monitoring for safety of a standard middeck payload

Static feed water electrolysis module

An advanced static feed water electrolysis module (SFWEM) and associated instrumentation for generating breathable O2 was developed. The system also generates a H2 byproduct for use in an air revitalization system for O2 recovery from metabolic CO2. Special attention was given to: (1) eliminating water feed compartment degassing, (2) eliminating need for zero gravity condenser/separators, (3) increasing current density capability, and (4) providing a self contained module so that operation is independent of laboratory instrumentation and complicated startup/shutdown procedures

Iodine generator for disinfecting reclaimed water

System dispenses iodine into water tank automatically in quantities varying from 0.5 to 20 ppm. It stores 180-day supply of iodine crystals, sufficient to support six people consuming water at rate of 4.5 to 13.6 kg per person per day

Iodine generator for reclaimed water purification

The system disclosed is for controlling the iodine level in a water supply in a spacecraft. It includes an iodine accumulator which stores crystalline iodine, an electrochemical valve to control the input of iodine to the drinking water and an iodine dispenser. A pump dispenses fluid through the iodine dispenser and an iodine sensor to a potable water tank storage. The iodine sensor electronically detects the iodine level in the water, and through electronic means, produces a correction current control. The correction current control operates the electro-chemical iodine valve to release iodine from the iodine accumulator into the iodine dispenser

One-man, self-contained CO2 concentrating system

A program to design, fabricate, and test a 1-man, self-contained, electrochemical CO2 concentrating system is described. The system was designed with electronic controls and instrumentation to regulate performance, to analyze and display performance trends, and to detect and isolate faults. Ground support accessories were included to provide power, fluids, and a Parametric Data Display allowing real time indication of operating status in engineering units

Effects of modifications to the space shuttle entry guidance and control systems

A nonlinear six degree of freedom entry simulation study was conducted to identify space shuttle guidance and control system software modifications which reduce the control system sensitivity to the guidance system sampling frequency. Several modifications which eliminated the control system sensitivity and associated control limit cycling were examined. The result of the modifications was a reduction in required reaction control system fuel

Development of an iodine generator for reclaimed water purification in manned spacecraft applications

A successful 30-day test is described of a prototype Iodine Generating and Dispensing System (IGDS). The IGDS was sized to iodinate the drinking water nominally consumed by six men, 4.5 to 13.6 kg (10 to 30 lb) water per man-day with a + or - 10 to 20% variation with iodine (I2) levels of 0.5 to 20 parts per million (ppm). The I2 treats reclaimed water to prevent or eliminate microorganism contamination. Treatment is maintained with a residual of I2 within the manned spacecraft water supply. A simplified version of the chlorogen water disinfection concept, developed by life systems for on-site generation of chlorine (Cl2), was used as a basis for IGDS development. Potable water contaminated with abundant E. Coliform Group organisms was treated by electrolytically generated I2 at levels of 5 to 10 ppm. In all instances, the E. coli were eliminated

Advanced combined iodine dispenser and detector

A total weight of 1.23 kg (2.7 lb), a total volume of 1213 cu m (74 cu in), and an average power consumption of 5.5W was achieved in the advanced combined iodine dispenser/detector by integrating the detector with the iodine source, arranging all iodinator components within a compact package and lowering the parasitic power to the detector and electronics circuits. These achievements surpassed the design goals of 1.36 kg (3.0 lb), 1671 cu m (102 cu in) and 8W. The reliability and maintainability were improved by reducing the detector lamp power, using an interchangeable lamp concept, making the electronic circuit boards easily accessible, providing redundant water seals and improving the accessibility to the iodine accumulator for refilling. The system was designed to iodinate (to 5 ppm iodine) the fuel cell water generated during 27 seven-day orbiter missions (equivalent to 18,500 kg (40,700 lb) of water) before the unit must be recharged with iodine crystals

Development of the reentry flight dynamics simulator for evaluation of space shuttle orbiter entry systems

A nonlinear, six degree of freedom, digital computer simulation of a vehicle which has constant mass properties and whose attitudes are controlled by both aerodynamic surfaces and reaction control system thrusters was developed. A rotating, oblate Earth model was used to describe the gravitational forces which affect long duration Earth entry trajectories. The program is executed in a nonreal time mode or connected to a simulation cockpit to conduct piloted and autopilot studies. The program guidance and control software used by the space shuttle orbiter for its descent from approximately 121.9 km to touchdown on the runway

Triple redundant hydrogen sensor with in situ calibration

To meet sensing and calibration needs, an in situ calibration technique was developed. It is based on electrolytic generation of a hydrogen/air atmosphere within a hydrogen sensor. The hydrogen is generated from water vapor in the air, and being electrical in nature, the in situ calibration can be performed completely automatically in remote locations. Triply redundant sensor elements are integrated within a single, compact housing, and digital logic provides inter-sensor comparisons to warn of and identify malfunctioning sensor elements. An evaluation of this concept is presented