Lockheed Martin Aeronautics

PRISCILLA P. NELSON, Director, Division of Civil and Mechanical Systems, Directorate of Engineering, National Science Foundation DONALD R. NILSON, Director, Engineering Technology Strategic Planning, Lockheed Martin Aeronautics Company JOHN D. NORTON, Staff Scientist, Medtronic, Inc. 

Jeffrey W. Hamstra and Daniel N. Miller Lockheed Martin Aeronautics Company Fort Worth, Texas... 

Jeffrey W. Hamstra Senior Manager Propulsion Systems Branch Lockheed Martin Aeronautics Company... 

Why do scientists wony about units The National Aeronautics and Space Administration (NASA) recently was reminded of just why keeping track of units is so important. In 1999 a 125 million satellite was lost in the atmosphere of Mars because scientists made some improper assumptions about units. NASA s scientists at the Jet Propulsion Lab (JPL) in Pasadena, California, received thrust data from the satellite s manufacturer, Lockheed Martin Aeronautics in Denver, Colorado. Unfortunately, the Denver scientists used American units in their measurements and the JPL scientists assumed the units were metric. This mistake caused the sateUite to fall 100 km lower into the Mars atmosphere than planned. The spacecraft burned up from the friction with the atmosphere. 

Lockheed Martin Aeronautical Systems Company Advanced Structures and Materials Division Marietta, GA 30063... 

Funding for the activity that led to this publication was provided by Cummins Engine Company, DaimlerChrysler Corporation Fund, Defense Advanced Research Projects Agency, Department of Defense Research and Engineering, Hewlett-Packard Company, Lockheed Martin Corporation, Lucent Technologies, Microsoft Corporation, National Aeronautics and Space Administration, Parsons Brinckerhoff, Inc., Pratt Whitney, San-dia National Laboratories, Science Applications International Corporation, Xerox Foundation, Xerox Research and Technology, and the National Academy of Engineering Fund. 

European Aeronautics Defense and Space Company (EADS), Netherlands— formed in 1999 by a merger of Diamler-Chrysler Aerospace and Aerospatiale Matra to form the third largest aerospace company, after Boeing and Lockheed Martin. 

---