Technology / Aviation / Dirigible: A lighter-than-air craft capable of being propelled and steered for controlled flight. Latin: dirigo,to steer.
Science / Periodic Table of Elements / Helium (He): Atomic number: 2, Atomic mass: 4.00260 g.mol -1, Electronegativity: unknown, Density: 0.178*10 -3 g.cm -3 at 20 °C, Melting point: - 272.2 (26 atm) °C, Boiling point: - 268.9 °C, Vanderwaals radius MORE
Technology / Aviation / Lighter-Than-Air Craft (LTAC): Generally referring to powered blimps and dirigibles, but often also includes free balloons. MORE