NASA is loading liquid hydrogen into its Space Launch System (SLS) moon rocket at the Kennedy Space Center. This operation, taking place on Thursday, is an important test of repairs made to a leaky umbilical, which caused a countdown rehearsal to stop on February 2.
The loading of liquid hydrogen into the rocket’s core stage was expected to start at launch complex 39B on Thursday morning. The test will check if new seals in the launch pad umbilical are effective. A NASA spokesperson explained that engineers are testing the new seals by partially filling the core stage tank with liquid hydrogen. The results will help plan the next wet dress rehearsal, a practice run for launching.
During the previous wet dress rehearsal, the launch team faced hydrogen leaks from the umbilical that sends propellant into the rocket. They managed the leaks by stopping and starting the fueling process, which allowed the seals to warm and close the leaks.
Liquid hydrogen can be challenging to manage because its small molecules can escape through tiny gaps. It can also be very explosive when mixed with air. In the February 2 fueling test, the launch team filled the tanks but stopped the countdown due to a large increase in hydrogen leakage during the final minutes.
If the tests on Thursday go well, NASA may organise a second wet dress rehearsal as soon as next week.
Vocabulary List:
- Umbilical /ʌmˈbɪlɪkəl/ (noun): A cord-like structure that connects the rocket to the fuel supply.
- Rehearsal /rɪˈhɜːr.səl/ (noun): A practice session for a performance or event.
- Explosive /ɪkˈspləʊsɪv/ (adjective): Able or likely to cause an explosion.
- Leaky /ˈliː.ki/ (adjective): Having a hole or crack through which liquid or gas can escape.
- Hydrogen /ˈhaɪdrədʒən/ (noun): A chemical element that is a colorless odorless gas and is highly flammable.
- Effective /ɪˈfɛktɪv/ (adjective): Successful in producing a desired or intended result.
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