Route optimization of the aircraft flight

A method of finding the aircraft optimal route by means of task-oriented replacement of the functional being optimized is proposed.     

Comparison of the empirical thermospheric models and the self-consistent model of the ionospheric plasma

The comparison of the self-consistent theoretical model with empirical models and experimental data is presented. The cause of the discrepancies of these models is discussed.     

Emerging views on a joint Soviet—US Mars mission

The political climate today is more favourable for joint superpower cooperation in space than it has been for many years. The authors of this Viewpoint, who studied together as members of the inaugural class of the International Space University, trace recent developments in the USA and USSR and evaluate how they might affect cooperation. Ironically, they find, it is the common problems both nations face in relation to space activities - budgetary constraints and declining political support for their space programmes - that argue most forcefully for cooperation. But a subtle and initially modest strategy will be needed to overcome the obstacles that stand in the way.