Japan says the LE-7 main engine of the H2S vehicle, which failed to place the MTSAT spacecraft into orbit on 15 November, suffered from cracks in the liquid hydrogen fuel tank or combustion chamber, causing the turbopump to stop operating 4min after the launch. The booster veered off course and was destroyed by the vehicle's auto-destruct system. Meanwhile, development has been delayed of an uprated booster, the H2A, incorporating a new LE7A engine and the LE5A second stage booster.
Source: Flight International