An expansion tube with a free piston driver has been used to generate quasi-steady hypersonic flows in argon and air at flow velocities in excess of 9 km/s. Irregular test flow unsteadiness has limited the performance of previous expansion tubes, and it has been found that this can be avoided by attention to the interaction between the test gas accelerating expansion and the contact surface in the primary shock tube. Test section measurements of pitot pressure, static pressure and flat plate heat transfer are reported. An approximate analytical theory has been developed for predicting the velocities achieved in the unsteady expansion of the ionising or dissociating test gas.

Heat transfer rates on a straight biconic, an attractive configuration for an aero-assisted orbital transfer vehicle, were made in the ANU T3 shock tunnel at various angles of attack and a stagnation enthalpy of 26 MJ/kg, equivalent to a flight speed of 7-2 km/s. The heat transfer database at this higher enthalpy has been compared with the data obtained on the same model in hypersonic and hypervelocity facilities elsewhere. The non-equilibrium flow effects on the model have been discussed in terms of the Hornung reaction rate parameter Ω.

A standard flat facet approximation for finite element analysis of general thin shells has been sought after for many years, but fundamental difficulties hindered the development of a definitive solution. Recent advances in the finite element method, however, have provided more rational resolutions of some of these difficulties than the kind of artifices which were employed formerly. This paper completes the theory of a basic triangular flat shell element which incorporates modern developments and meets practical criteria of mathematical simplicity and general applicability. The flat facet shell element is also, potentially, an appropriate basis for constructing a better curved approximation to a shell surface in order to achieve improved accuracy. Numerical results are given for a variety of shell test problems to provide comparisons with accepted benchmark solutions and to assess the available accuracy relative to other finite element formulations.

In recent years, interest has grown in the use of small satellites for a variety of applications. In certain missions, where propulsion systems are necessary, electric propulsion technology can offer advantages. Small satellite technology and applications are reviewed and some of the features of various types of electric propulsion are discussed: missions where small satellites might use electric propulsion are described.