Electrostatic Probe Data from Bell Sphere BO9

Bell Sphere B09 was a 140-lb, 15-in.-diam beryllium sphere which was launched on a suborbital trajectory and re-entered the Earth's atmosphere with a velocity of approximately 6 km/sec. The probe geometries and locations were: a flush disk and a thin wire normal to the surface, each 6° off the front stagnation point, a flush disk 100° off the stagnation point, and a thin wire on a 2-in. support in the base recirculation region. The altitude ranges for which data were obtained are shown in Table 1. The motion of the sphere during re-entry was complicated and the probe currents were therefore strongly modulated and depended not only upon the ionization level, but also upon the instantaneous location of the probes in the flowfield. The sphere motion has been resolved and both data and results are presented a) at a fixed angle off the stagnation point as a function of altitude, and b) at a fixed altitude as a function of angle off the stagnation point. Only the results of the former will be presented in this synoptic. Other results obtained are the electron-to-ion current ratios and plasma potential measurements.