山田 哲哉

The thermal response of ablative TPS of the Hayabusa capsule is calculated along the most probable reentry trajectory by using the integrated analysis method. The analysis method consists of an axisymmetric nonequilibrium Navier-Stokes flow solver and the radiative heat transfer analysis code loosely coupled to a ablation thermal response code. The calculated results are compared with the flight data obtained at the present time. It is found that a reasonable agreement is obtained between the calculated surface temperature and the temperature values estimated from blackbody spectrum obtained by DC-8 airborne observation and the ground observation. The calculated surface recession overestimates the measurement along the wall surface by a factor of three. On the contrary, the density distributions calculated by taking account of nitration reaction reproduce the flight data moderately both at the stagnation point and the downstream region. Especially in the downstream region, the calculated thickness of char lyer overestimates the flight data when we consider the effect of turbulence due to the pyrolysis gas, while it underestimates the flight data when the effect of surface roughness of ablative TPS is taken into account. © 2011 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.

Japan has launched many interplanetary spacecraft for exploration of solar system bodies including Mars. Now we are planning the next Mars mission in the late 2010's. This paper describes the preliminary mission analysis and orbit design for this plan. The combined exploration by several spacecraft requires complicated and careful consideration, different from those for single-probe missions. Mission plans to realize required configuration by a single launch and simple simulation results are reported.