MEASUREMENTS OF ULTRAVIOLET-RADIATION FROM A 5-KM S BOW SHOCK/

Ultraviolet emission from a 5.1-km/s re-entry bow shock was measured i n a sounding rocket experiment launched from the Barking Sands Researc h Range (Kauai, Hawaii) in February 1991 at 14:30 GMT. Optical data we re obtained on the downleg portion of the flight as the payload descen ded from 115 to 62 km in a very shallow trajectory at a nearly constan t speed. The intensity of the ultraviolet spectrum (lambda200-400 nm), and the vacuum ultraviolet resonance radiation emitted by atomic oxyg en and hydrogen at lambda130.4 nm and lambda121.5 nm, respectively, we re measured. Data from optical instruments in the 200-400-nm spectral region is presented here. Langmuir probe measurements provided data on the total plasma density and electron temperature in the boundary lay er over a limited altitude range.