that propellant sloshing was caused by the tilting program to such a degree that the missile became dynamically unstable 78 . A rather ingenious testing device was rigged by ABMA in the attempt to cope with the sloshing problem. A JUPITER center section was placed on a railroad  flat car, with proper attachments that would simulate flight environment forces on the propellant tanks, and several types of baffles were placed inside  the tanks as a means to reduce the sloshing. Success was attained by installing a turncated-cone type in the fuel tank and an accordion type in the LOX  tank. The full- scale IRBM flight of JUPITER 1 in May 1957 aptly demonstrated two major points: (1) quick reaction of an in-house R&D team and the resulting brevity in time between problem isolation and component fix, and (2) the validity of heavily instrumented R&D flights. The above represented the major problem areas in the propulsion system development program. This is not to say that problems of the moment were  not experienced with other components. For example, during the early flights of the solid propellant vernier engine, some failures did occur, but quite  often it was hard to tell whether or not the difficulty had been caused by main engine failures. In any event, development progress was not deterred by  the other propulsion components, which never became major problem areas.  _____________________________

78. Hist, ABMA, Jan-Jun 57, pp. 42-46; JUP Prog Rpt for May 57, 6 Jun 57; JUP Prog Rpt for Oct 57, Hist Off files .