Contract aerospace engineers are independent contractors who work for aerospace companies on a short- or long-term contract basis. Your specific job duties vary, depending on the scope of the project and the type of company. Responsibilities may include designing parts for airplanes, researching technology for spacecraft and satellites, or developing the tools necessary for making industry parts used in different machinery. Contract aerospace engineers often focus on specific areas, such as mechanical systems or navigation and control components. These positions typically last anywhere from several weeks to a few months; contracts that last longer than a year are relatively rare.