Increasingly, members of the aerospace work force are turning to distance education as an alternative to the traditional path of graduate study. Today, the aerospace industry is especially prone to use this form of education because it is convenient and will not interfere with the jobs of key personnel. Aerospace jobs are dominated by security interests making it difficult to leave for a prolonged period of time in order to meet any form of residency requirement. There is also the loss of income that accompanies a leave of absence. Many senior level professionals cannot sustain this loss of salary to return to school so graduate education becomes a trade off against future earnings.