WASHINGTON — World View announced June 5 it performed the longest flight to date of its stratospheric balloon, demonstrating its ability to carry out missions traditionally reserved for satellites. The company said its Stratollite balloon system recently completed a 16-day test flight, taking off May 18 from the company’s headquarters in Tucson, Arizona, and landing June 3 in Nevada. Prior to this flight, the longest flight by a Stratollite was five days. In addition to proving its ability for extended flights, the Stratollite also demonstrated its ability to maintain position. That included “multiple” tests where the balloon stayed within an...