English: In September of 1959, JPL held a press conference to celebratethe opening of its new ,500,000 hypersonic wind tunnel, thethird wind tunnel built at JPL from 1947 to 1959. A JPL engineeris shown positioning a scale model of a missile in the tunnel's21 x 21 inch test section. The two horizontal stainless steelplates were flexible and could be moved by a system of hydraulicjacks seen above and below, to change the speed of the airflowand other variables. Testing time was to be used equally by ArmyOrdnance contractors, Air Force contractors, and the JPLAerodynamic Research Section. This NASA wind tunnel isespecially noteworthy, as JPL has mostly concentrated on astronautical research as opposed to aeronautical. This is aunique wind tunnel in that not only is it at JPL, but as DonaldBaals and William Corliss state in Wind Tunnels of NASA (NASASP-440), "the hypersonic facility was a particularly significantaddition to the existing NACA spectrum of tunnels. Covering therange from Mach 4 to Mach 11, with continuous-flow capability,it operated at pressures up to 715 psi and temperatures to 1350? F."