It is an inert gas, so that is what they use to force the propellants from the tanks to force them into the nozzles on the reaction control system. No helium means no control over the spacecraft.
Yeah, to pressurize the navigational thrusters tanks, basically.
I pray the problem was a bit more complicated than that, but you summed it up completely in 2 sentences. That makes me sad. How can you fly in a plane, let alone into outer space with these guys anywhere on the payroll?