4 Damage of Graphite
On Feb. 11, the next day of the launch, around 70 pieces of graphite-like fragments were found. The outward resemblance was black lead, and on the surface of some of them was stuck white or gray material. A polarizing microscope found the fragments to be very similar to graphite at the nozzle in terms of granurality, crystallinity, and porosity. Their specific gravities were almost the same. Ultimate analysis showed the main ingredient of the white or gray material was aluminum. ISAS came to a conclusion that the fragments around the launch pad were the graphite used at the nozzle insert, and the sticking materials were the aluminum oxide. The graphite turned out to begin to be broken just after the ignition. This early stage breakage is thought to have occurred at the place that had no effect on the nozzle configuration. And on the basis of the flight results in the past, the inner pressure has been judged to be normal from ignition till 25 seconds.
1 How did M-V-4 fly?
2 The abnormal attitude of the 1st stage was everything.
3 What caused the abnormal attitude?
4 Damage of Graphite
5 Current Situation
