Similarities in the plasma wake of the moon and space shuttle

W. M. Farrell, A. C. Tribble, and J. T. Steinberg

NASA Goddard Space Flight Center, Greenbelt, Maryland 20771

Abstract:

As a result of the Wind spacecraft encounters with the moon, a new view of the lunar wake in the high-density solar wind plasma has emerged. Specifically, the lunar wake was considered to be magnetosonic in nature but is now demonstrated to be a kinetically driven structure filling in via ion sonic disturbances. The structure appears to be determined via kinetic plasma microinstabilities, rather than a bulk magnetohydrodynamicshock. Examining the specific structure, it becomes apparent that the lunar wake and that of the space shuttle have many similarities, suggesting that the shuttle wake is also driven via kinetic instabilities. Comparisons of the two wakes are presented in detail, illustrating the dominance of the kinetic phenomena in the replenishment of both plasma voids. The general concepts presented in this study have applications to other structures immersed in a plasma flow, including the space station.

J. Spacecraft & Rockets, Vol. 39, No. 5, September-October, 2002