T purpose of this Note is to report on some turbulent base heating measurements obtained from flight tests of a very slender re-entry vehicle. This unique data is limited in scope since the measurements were obtained primarily as diagnostic information. Data accuracy is estimated to be ±10%. A single copper slug calorimeter was used to obtain base heating rates on each of seven flights of nearly identical vehicle configurations, but on two different re-entry trajectories. Vehicle characteristics include a half-cone angle of 4.5°, nose bluntness ratio = 0.035 (graphite nose tip), and either a phenolic silica or phenolic carbon heatshield on the seven foot long flat-based vehicles. Re-entry performance was generally nominal for the two typical ballistic re-entry trajectories given in Table 1 . The calorimeter copper slug used a copper-constantan thermocouple bead soldered to the backface of the slug on all flights except the first. No correction was made for temperature gradients in the slug. The reliable calibration limit is 555°F. Data above this limit are not included. On the first flight, a resistance thermometer gage was bonded to the slug backface. This vehicle was the only one with the base heating measurement at a relative base radial station, RlRb = 0.66. All other flight measurements were made at R/Rb = 0.22. Due to the lower heating rates on flight one, data were obtained to impact. Data reduction was performed only for altitudes of 100,000 ft and below, relating primarily to the turbulent flow regime. Smoothing of raw temperature data was performed manually, and the resultant temperatures fit to a second order polynominal to obtain temperature-time slope information, dT/dt. Base heating rates were computed from CpMdT