The Pentagon's development of the F-35 Joint Strike Fighter jet has already cost the government $400 billion. The plane, designed to replace nearly all of the tactical fighters used by the U.S. Air Force, Navy and Marine Corps, is now projected to cost over $1 trillion to develop, procure and support through 2050. One reason for the huge expense is that planes are being built even before their development and testing are completed. As plans change, planes already constructed need to be retrofitted. The software needed to make the planes combat ready is "as complex as anything on earth," according to the government (ProPublica, March 23).