 The MX-776A development developed the RTV-A-4 Shrike later re-designated the X-9 as a testbed for the RASCAL that would be developed under project MX-776B.22 X-9 missiles were launched between April 1949 and January 1953.In May 1947, the USAAF awarded the Bell Aircraft Company a contract for the construction of a supersonic air-to-surface missile compatible with the B-29 Superfortress, the B-36 bomber, and the B-50 Superfortress bomber.