<h2>AAS 97-133</h2>
<h2>AN ESTIMATION OF HAZARDS IN THE SPACE ENVIRONMENT FOR A  LONG-RANGE HYPERSONIC TRANSPORT USING EXO-ATMOSPHERIC  COAST                            </h2>
<h4> D. G. Tuckness, Jr. and T. McGaha, The University of Texas at Arlington                                                                                                  </h4>
<h2> Abstract </h2>
 This paper examines the hazards of using an exo-atmospheric coast phase for a long- range hypersonic transport aircraft.  The chief hazards in the space environment  are collision with space debris and radiation dosage from a transit of the Van  Allen belts.  The hazards are assessed for both the minimum energy ballistic  trajectory and for the fractional orbit coast trajectory, and both are compared  against the expected hazards of operating a high-atmospheric cruise vehicle.