The twin composite liquid hydrogen (LH) tanks of the Lockheed Martin X-33 advanced technology demonstrator for future single-stage-to-orbit vehicles will begin crucial pressure and stress testing at NASA's Marshall Space Flight Center, Huntsville, this week. The two 2,080kg tanks, built by Alliant Techsystems, which each carry 110,000litres (29,000USgal) of LH at -252C¼, represent half of the X-33's airframe. The tanks, which were designed to conform to the craft's body shape, will provide the structural strength of the vehicle.
Source: Flight International