То есть они сначала обнаружили падение давления гелия наддува в топливной системе маневровых двигателей, потом обнаружили негерметичность по фланцу, затянули болты потуже, но утечка гелия не прекратилась. После этого они зажмурились и сказали, что утечка некритична и не повлияет на выполнение полëта. Но потом кто-то сообразил, что звучит это как-то слишком залихватски, и в НАСА решили дать минимум 4 дня на устранение утечки.
У НАСА осталось шт. 12 этих двигателей (РД-180) Все пуски Атласа-5 уже расписаны. Утечка гелия произошла на Старлайне, на его двигателях (трубопроводе) The unrelated helium leak in the Starliner's propellant pressurization system was noted during the original countdown to launch, but it remained within safe limits for flight. After the Atlas 5 and Starliner were rolled back to the VIF for the oxygen valve replacement, managers decided to take a closer look at the helium issue. The leak was detected in plumbing making up helium manifold No. 2 inside one of four "doghouse" assemblies spaced around the exterior of the Starliner's drum-shaped service module. Each doghouse features four Orbital Maneuvering and Attitude Control — OMAC — thrusters, and four small reaction control system maneuvering jets. Pressurized helium gas is used to push propellants to the rocket motors in each doghouse, as well as to four powerful launch abort engines that would only be fired in the event of a catastrophic problem with the Atlas 5 on the way to orbit. Engineers tightened bolts in a flange where the leak was detected, pressurized the lines and then ran tests to determine if the leak was still present. In the meantime, launch was re-targeted for May 21. But as it turned out, tests revealed the leak was still present. Mission managers considered a range of options for resolving the issue, but they decided Friday to press ahead toward a launch opportunity on May 25, pending additional data reviews and analysis to show the leak, which is currently stable and within acceptable limits, will not worsen in flight. "Pressure testing...showed the leak in the flange is stable and would not pose a risk at that level during the flight," NASA said in a blog post. "The testing also indicated the rest of the thruster system is sealed effectively across the entire service module. "Boeing teams are working to develop operational procedures to ensure the system retains sufficient performance capability and appropriate redundancy during the flight. As that work proceeds, (mission managers) will take the next few days to review the data and procedures to make a final determination before proceeding to flight countdown."
Но потом кто-то сообразил, что звучит это как-то слишком залихватски, и в НАСА решили дать минимум 4 дня на устранение утечки.
Уж наверное пора переключаться на Blue Origin
и SpaceX
The leak was detected in plumbing making up helium manifold No. 2 inside one of four "doghouse" assemblies spaced around the exterior of the Starliner's drum-shaped service module. Each doghouse features four Orbital Maneuvering and Attitude Control — OMAC — thrusters, and four small reaction control system maneuvering jets.
Pressurized helium gas is used to push propellants to the rocket motors in each doghouse, as well as to four powerful launch abort engines that would only be fired in the event of a catastrophic problem with the Atlas 5 on the way to orbit.
Engineers tightened bolts in a flange where the leak was detected, pressurized the lines and then ran tests to determine if the leak was still present. In the meantime, launch was re-targeted for May 21.
But as it turned out, tests revealed the leak was still present. Mission managers considered a range of options for resolving the issue, but they decided Friday to press ahead toward a launch opportunity on May 25, pending additional data reviews and analysis to show the leak, which is currently stable and within acceptable limits, will not worsen in flight.
"Pressure testing...showed the leak in the flange is stable and would not pose a risk at that level during the flight," NASA said in a blog post. "The testing also indicated the rest of the thruster system is sealed effectively across the entire service module.
"Boeing teams are working to develop operational procedures to ensure the system retains sufficient performance capability and appropriate redundancy during the flight. As that work proceeds, (mission managers) will take the next few days to review the data and procedures to make a final determination before proceeding to flight countdown."