SpaceX has concluded its investigation into the engine failure occurred during the launch of a Falcon 9 on July 11. The company filed an “accident report” with the Federal Aviation Administration (FAA) and is ready to launch the Falcon 9 rocket again as early as tomorrow.
SpaceX’s investigation team, in collaboration with the FAA, determined that the July 11 failure was caused by a loss of liquid oxygen developed during the initial burn of the Falcon 9 second stage engine.
The failure on July 11 was caused by a loose clamp.
The loss is caused by a crack in a pressure sensor sensing line which is part of the rocket’s oxygen system. A clamp that normally holds the sensing line in place had come loose, subjecting it to excessive engine vibration that eventually caused it to fatigue and crack.
The leak of liquid oxygen on the second stage of the Falcon 9 rocket caused “excessive cooling of engine componentsparticularly those associated with the delivery of ignition fluid to the engine,” according to a statement on the SpaceX website.
Instead of a second controlled combustion, the engine underwent what SpaceX describes it as a “rough start”damaging it and causing loss of control of the second stage trim.
However, the second stage accident meant that Starlink satellites carried by the Falcon 9 were deployed into a lower orbitwhere “an extremely high aerodynamic drag environment” caused all 20 to re-enter Earth’s atmosphere, where they hopefully disintegrated.
To get the Falcon 9 back in the air as soon as possible, SpaceX engineers they will simply remove the sensing line and the sensor that failed on the second stage engine. “The sensor is not used by the flight safety system and can be masked by alternative sensors already present on the engine.”
The company also inspected, cleaned and replaced some of the sensing lines and clamps on its “active booster fleet.” The modifications have already been tested by SpaceX at its McGregor, Texas, facility under FAA supervision.
Now that the investigation is complete, the Falcon 9 rocket is no longer grounded and can return to service. The company’s website indicates that SpaceX is aiming for July 27 at 12:21 ET for the next launch of the Falcon 9 which will carry 23 Starlink satellites from NASA’s Kennedy Space Center, with additional launch window opportunities available later in the day and on July 28.
Source: www.tomshw.it
