'Blended wing' craft passes wind-tunnel tests

New Scientist Breaking News - 'Blended wing' craft passes wind-tunnel tests

Saw this on NASA TV, and it left me wondering if the umbilical, besides sending control data from the three "pilots" and recording sensor data, also sent electricity to power the three engines during it's free flight. If not, then I don't see how the craft maintained it's position in the wind-tunnel.