The Measurement of Air Pollution from Satellite (MAPS) experiment measured the distribution of middle tropospheric carbon monoxide (CO) from the space shuttle during October 1984. The data represent average mixing ratios in the middle troposphere between 57°N and 57°S. Approximately 75,000 individual CO measurements were obtained during the 9‐day mission. The data are presented in maps that show the CO mixing ratios averaged over 5° latitude by 5° longitude areas for 6 days of the mission. Comparisons with concurrent, direct measurements taken aboard aircraft show that the inferred concentrations are systematically low by 20–40% depending upon which direct measurement calibration standard is used. The data show that there are very large CO sources resulting from biomass burning over South America and southern Africa. Measured mixing ratios were high over northeast Asia and were highly variable over Europe.
During the second flight of the space shuttle, the measurement of air pollution from satellites (MAPS) experiment in the OSTA-1 payload acquired approximately 35 hours of radiometric measurements of the carbon monoxide mixing ratio in the middle troposphere, upper troposphere, and lower stratosphere. A gas filter radiometer operating in the 4.67-micrometer band was used to acquire the data over the region from 38 degrees N to 38 degrees S during both daytime and nighttime. The performance of the measurement system was excellent. The data reduced to date indicate the presence of significant gradients in the middle tropospheric carbon monoxide mixing ratio with both latitude and longitude over the North Atlantic, the Mediterranean Sea, and the Middle East. On the basis of comparisons with directly measured values, the accuracy of the measurements is approximately 15 percent. Comparisons of data taken on successive orbits over the same geographic region indicate that the repeatability of the measurements is approximately 5 percent.
In two separate flights in 2004, the X-43A became the fastest aircraft ever to fly with an airbreathing propulsion system, reaching nearly Mach 7 in its first flight and approaching Mach 10 in its second flight. The X-43A was designed and manufactured by a contractor team of ATK GASL and Boeing. This paper recounts some of the design and manufacturing key features and challenges faced by the contractor team. That these challenges were successfully met is demonstrated by the success of the two flights, in both of which the aircraft and engine, its subsystems, and its separation system had to work the first time in flight. The research instrumentation system and all the integrated sensors performed as desired. Therefore, these two flights produced a wealth of aerodynamic and propulsion data, but moreover demonstrated that hypersonic aircraft can be designed and built using engineering tools and technologies available today.
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