already makes aeroplanes and launches rockets. Now two Germans working for the US-based company have their sights set on an airship that takes off like a rocket.
The object is to create a lighter-than-air (LTA) craft that can hover at 15 kilometres or more after launching from a site much smaller than is usual for LTAs. The craft would be used for surveillance or communications.
The traditional way to launch an airship is to tether it horizontally and then cast off from both ends, so the craft lifts gracefully. But it needs a lot of room.
So Boeing fills the ship with helium while the rear is tethered with a short fixed line and the front with a much longer line that pays out as more gas is pumped into the front end. The nose rises in the air, until the craft is standing nearly vertical.
Both lines are then cast off at the same time and the airship shoots up like a rocket, at around 5 metres a second.
As the ship rises, a valve at the rear vents air, and the helium at the top expands - due to the lower atmospheric pressure at altitude - to fill the entire ship. This brings the blimp horizontal, enabling it to hover.