Purple Pigeon, Interplanetary Automated Shuttle, 20 July 1976. [Description from photo index.]. Between 1976 and 1982 JPL became smaller and redefined its direction of development, primarily due to changes in funding and NASA policies. Bruce Murray, the new JPL Lab Director in April 1976, sought different projects for JPL, such as high-tech military research. But Murray also advocated new exploration missions for the Eighties. JPL dreamed of a future that extended planetary exploration. Murray believed new projects would have to include pizzazz to attract public and scientific support. Missions such as these he called "Purple Pigeons" -- Mars exploration using a wheeled rover, orbiter/landers for both Jupiter and Saturn, an asteroid rendezvous and imaging mission, and an automated Moon station, to name a few. Missions that might lack popular support were termed "Gray Mice." The image above is the earliest depiction of a Purple Pigeon, drawn within three months of Murray becoming Director. Called an "Interplanetary Automated Shuttle," it used a solar sail technique. Its expected applications included "asteroid mining, Mercury/Venus sample return, and cometary sample return." 111-4 -- INTERPLANETARY MILK RUN -- A 700-meter square Solar Sail proposed by NASA-JPL scientists for the mid-1980s could be used to receive freight packages carried to it by the Space Shuttle for delivery to Mercury, Venus or Mars. The rechargeable sail (using the Sun's photon energy) might become an interplanetary ferry for returning Mars samples to Earth or taking multiple spacecraft to Venus, Mercury, or even (as shown here) into orbit closer to the Sun.. [Caption from released photo.].
