NASA is preparing for the second attempt at the dress rehearsal of the Artemis II mission - the first manned flyby of the moon in half a century. However, the preparation faces a technical problem, which already delayed the previous start: an elusive leak of hydrogen. Engineers will conduct a key test this week, which will determine, will the rocket be able to fly in March.
Last week, during the first dress rehearsal of the refueling of the Space Launch System's high-powered rocket (SLS) there was a fuel leak. Hydrogen molecules found a loophole in one of the joints of the tail service mast - structure, which feeds the rocket with fuel directly on the launch table. Liquid hydrogen is extremely cold (-253°C) and has such small molecules, which is able to seep through microscopic gaps in the seals, which perfectly hold any other liquid. Extreme cold additionally makes metal parts brittle, provoking the appearance of cracks right there, where they are least expected.
19 February teams will try to count down to 29 seconds before the start, stopping before igniting the engines. If the test is successful, March launch window (6-11 March) will remain real.
Source: https://universemagazine.com