' , a . 1. Cie tea aol heToate et ee le ald adhd Bitealees ae ae ot 3. PROJECT AIRSTREAM by Philip W. Krey (HASL) Michael Kleinman (HASL) Project Airstream is HASL's study of radioactivity in the lower stratosphere emplcying the RB-57F aircraft as a sampling platform. The bircraft are flown by the 58th Weather Reconnaissance Squadron under Hhe direction of the 9th Weather Wing of the Air Weather Service. This project iS a continuation of the Defense Atomic Support Agency's Propect Stardust except that Airstream's sampling missions are limited to pbnly one per season. The data in this report cover the missions flown in April, and October 1969. July Previous reports containing results from this pro- gram are given in references 1 through 8. FLIGHT SCHEDULE Airstream missions are scheduled for February, May, August and November with a + one month slippage. However, completed within a nine day interval. The first Airstream mission was flown in August 1967. each mission must be The flight trajectory and altitude coverage of an Airstream mission are shown in Figures 3a and 3b, Prior te February 1969, respectively. a large gap in the altitude coverage between 15.2 and 18.3 km existed in the sensitive polar regions of each hemisphere. II - wr mee me me 9