Shuttle Program

After it has been separated, hydrogen is an unusually clean-energy carrier and clean enough for the U.S. space shuttle program to use hydrogen-powered fuel cells to operate the shuttle s electrical systems while the by-product of drinking water is used by the crew. 

Is it time to rethink the manned space program Despite the Columbia, Challenger, and Apollo disasters, NASA has called for the shuttle program to continue. President Bush s January 2004 initiative for a moon base and manned flights to Mars has led to much discussion about cost, safety, and priorities. 

Alkaline fuel cell (AFC) was used for Apollo and Space Shuttle program. Alkaline fuel cell employs liquid alkaline, e.g., KOH, as an electrolyte so that fuel, as well as air or oxygen, should be free of CO2 because the strong alkaline electrolyte reacts with CO2 to form carbonates, which reduces the ionic conductivity. Electrodes, e.g., Ni, Ag, and metal oxides, are relatively inexpensive compared to that of other fuel cells. 

Space Shuttle Program Petition for HCFC 141b Exemption Allowance. NASA http //www.nasa.gov/pdf/45331main hcfc5 002.pdf (accessed 5/2006)... 

A decade later another plant was built at Michoud to serve the Space Shuttle program. This plant was similar to the earlier plant at Michoud, in fuel source and in process cycle. 

Aeronautics and Space Administration space shuttle program. However, the high glass transition temperatures of polyimides make processing difficult. Thus, the acid and amine monomers often are polymerized in solution to form a poly(amic-acid) resin. This polyimide precursor resin solution may be applied then to a fiber backing and cured at 200-300°C to form a thermally stable polyimide composite. 

The largest LH2 tank constructed so far is the NASA 3407 vacuum perlite-insulated spherical storage tank at the Kennedy Space Center, Florida, used in the US space shuttle program. The outer sphere is made from carbon steel with an inside diameter of 21.34 m and the inner sphere is made from austenitic stainless steel with an inside diameter of 18.75 m the ullage is about 10 %. The tank has a boiloff rate of 0.03 % or approx. 800 1 per day [51]. For comparison purposes the LH2 storage tank within the External Tank (47 m height, 8.4 m diameter) of the US Space Shuttle has a volume of almost 1600 m. ... 

Space Shuttle Program Safety and Mission Assurnace Manager... 

Following the successful completion of the orbital flight test phase of the Shuttle program, the system was declared to be operational. Subsequently, several safety, reliabihty, and quality assurance organizations found themselves with reduced and/or reorganized functional capabilities.. . . The apparent reason for such actions was a perception that less safety, reliability, and quality assurance activity would be required during routine Shuttle operations. This reasoning was faulty. 

The desire to predict the future often leads to collecting a large amount of information based on the hope that something useful will be obtained and noticed. The NASA Space Shuttle program was collecting six hundred metrics a month before the loss of Columbia. Companies often collect data on occupational safety, such as days without a lost time accident, and they assume that these data reflect on system safety [17], which of course it does not. Not only is this misuse of data potentially misleading, but collecting information that may not be indicative of real risk diverts limited resources and attention from more effective risk-reduction efforts. 

After the Columbia accident, safety standards in the Space Shuttle program (and the rest of NASA) were effectively anchored and protected from dilution over time by moving responsibility for them outside the projects. 

Ocasio, W. (2005) The opacity of risk Language and the culture of safely in NASA s space shuttle program , in W. H. Starbuck and M. Farjoun (eds.) Organization at the Limit Lessons from the Columbia Disaster. Blackwell Malden, p. 103-115. 

Other workers gradually went to less concentrated alkali (30-40% KOH) than found in Bacon s and P W s batteries. For the space shuttle program, United Technology Corporation (UTC-Power) developed a battery of alkaline fuel cells where 35% KOH immobilized in an asbestos matrix was used as the electrolyte. The electrodes contained a relatively large amount of platinum catalysts, so that at a temperature of 250°C it was possible to work at very high current densities, of up to 1 A/cm. ... 

Safety, reliability, maintainability, and quality provisions for the space shuttle program... 

The real development of carbon-earbon composites started in 1958, with US Air Force sponsored work, which later received a massive boost with the onset of the Space Shuttle Program. Carbon-carbon composites can be tailor-made to give a wide family of products by controlling the choice of fiber type, fiber presentation and matrix. 

Electrochemical Impedance Studies of AFC Cathodes. A review of the state of the art of alkaline fuel cell is given by McLean et al. [2002]. The electrolyte in AFC is a concentrated KOH solution, 25-50 wt% when operated at 120°C or below and in older AFC systems, operated at 250°C a 85 w/o KOH solution was used. The AFC was first fuel cell developed to technical maturity, based on the fundamental research of Bacon [1952] and has been employed extensively in the NASA space programs Apollo program (1960-1965) and space shuttle program (since 1981). 

The author wishes to thank her colleagues at NASA-JSC, Dr Eric Darcy, Mr Gilbert Varela, Mr Frank Davies and a former colleague, Mr Pranav Patel, for their collaborative work as well as the test services (Mobile Power Solutions, Symmetry Resources and Applied Power International) that have worked in conjunction with NASA-JSC in the past 15 years. The author is also very grateful to the NASA Engineering and Safety Center (NESC), International Space Station (ISS) and Space Shuttle programs that funded a majority of the work carried out on this subject at NASA-JSC. 

The human venture in space is also under stress as the U.S. space shuttle program ends without another human-carrying vehicle to replace it. The future of the one remaining space station is in doubt, and there are no plans to build another. 

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