At the same time, design engineering education receives less emphasis and is not being integrated with scientific and engineering analysis-oriented classes. In addition, design engineers used to provide the original focus for concurrent engineering, but now much of concurrent engineering is being formally developed by non-design engineers as a new way of doing engineering. Some of these formal approaches are inhibiting design engineering's effectiveness.

In response to these problems, some engineering schools are incorporating engineering design and capstone design courses into their curricula. National design competitions and special school design projects leading to hardware fabrication are gaining more support in both academia and industry. Not only do student teams learn the design process from such projects, but they are exposed to and practice concurrent engineering as well.

For example, 43 students at Mississippi State University's Raspet Flight Research Laboratory worked nine months to design and build an all-composite, one-third scale model of the X-30 National Aerospace Plane. The SO-ft, 5,000-1b, hypersonic single-stage-to-orbit model was displayed in June at the U.S. Air and Trade Show in Dayton.

In industry, there have been several design, fabrication, and testing successes in the NASP program. These designs illustrate the benefits of early concurrent engineering and exemplify the kinds of challenges new designers will face in the future.

Students at Mississippi State University’s Raspect Flight Research Laboratorydesigned and built an all-composite, one-third scale model of the NASP.

NASP tankage must contain pressurized liquid hydrogen and operate between -453 F and +250 F. Cryogenic testing was performed to validate the proposed materials and design concept. Filling and cycling the tank with liquid hydrogen at operating pressures demonstrated the tank's ability to withstand design limit pressures at cryogenic temperatures without leakage. This success substantiated use of the material systems for the NASP tankage.

McDonnell Douglas designed and built a larger, more complex NASP fuselage/tank test article. This 4-ft-high, 8-ft-wide, 8-ftlong, quarter-scale test article has a carbon/ epoxy liquid hydrogen fuel tank suspended inside a silicon carbide/titanium metal matrix composite fuselage. The cryogenic tank contains internal restraints to prevent the multibubble cross section from deforming while pressurized. The design challenge here was to accommodate the large temperature differences between the fuselage (at 1,500 F) and the cryogenic tank (at -453 F). Tests that simulated subsonic and hypersonic design conditions used both thermal and mechanical loadings. The test article successfully survived a maximum thermal loading condition while filled with hydrogen fuel.

Such successes illustrate how the design engineering community can work collectively to overcome the difficulties that currently threaten the aerospace industry. At the same time, the community's expertise must focus on ensuring that the knowledge gained is effectively shared. Increased coaching and mentoring of new design engineers, active concurrent engineering participation, improved design teaching methods, and the building and testing of more technology demonstration prototypes will be required to maintain aerospace engineering design excellence.