NASA and Lockheed Martin have not reached any agreement on who will pay to replace the composite liquid hydrogen tank on the X-33 space vehicle or whether to use a metal or composite tank. Due to faulty curing, the inner lining of the tank had extensive micro-cracks, allowing liquid hydrogen to seep into the honeycomb structure during a test. When the test was over, the droplets of liquid hydrogen expanded, blowing holes in the tank.--Stephen V Cole