A complete Moon is in view from Launch Complex 39B at NASAs Kennedy Space Center in Florida on June 14, 2022. The Artemis I Space Launch System (SLS) and Orion spacecraft, atop the mobile launcher, were being prepared for a wet dress rehearsal to practice timelines and procedures for launch. Release controllers then established a strategy to mask information associated with the leak that would activate a hold by the ground launch sequencer, or launch computer system, in a real launch day situation, to enable them to get as far into the countdown as possible. During the terminal count, the teams performed several critical operations that need to be achieved for launch including changing control from the ground launch sequencer to the automated launch sequencer controlled by the rockets flight software, and important action that the group wanted to achieve.
This second Artemis I damp gown practice session began on June 18, 2022. After the launch group reached their stations inside the Launch Control Center at NASAs Kennedy Space Center in Florida at approximately 5 p.m. EDT to start the damp dress rehearsal test for NASAs Artemis I mission. The countdown started 30 minutes later on at 5:30 p.m. or L-45 hours, 10 minutes prior to the preliminary target T-0 of 2:40 p.m. on Monday, June 20.
Overnight from June 18th to the 19th, engineers powered up the Orion spacecraft and the Space Launch Systems core phase. Teams likewise configured numerous systems on the rocket, spacecraft, and ground and carried out activities to prepare umbilicals that link the rocket and spacecraft to the mobile launcher and are used to provide power, communications, coolant, and propellant.
On the early morning of June 20, the launch control group began chill down operations and resumed the countdown clock ahead of streaming super cold liquid oxygen (LOX) into the core stage tank. The T-0 time for todays test is now 4:38 p.m. EDT for the first of the two terminal count runs for the wet dress rehearsal.
The process for filling the core stage tank begins with the chill down, or cooling, of the propellant lines to pack the liquid oxygen and liquid hydrogen in preparation for tanking. The team will gradually fill liquid oxygen into the core stage tank with the quick fill beginning not long after. Groups will then proceed to gradually fill the core stages liquid hydrogen tank followed by quick fill
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A full Moon is in view from Launch Complex 39B at NASAs Kennedy Space Center in Florida on June 14, 2022. The Artemis I Space Launch System (SLS) and Orion spacecraft, atop the mobile launcher, were being prepared for a wet dress rehearsal to practice timelines and procedures for launch.
The Artemis I damp dress practice session ended yesterday (June 20, 2022) at 7:37 p.m. EDT (4:37 p.m. EDT) at T-29 seconds in the countdown. This test marked the very first time the team totally packed all the Space Launch System rockets propellant tanks and continued into the terminal launch countdown, when lots of critical activities occur in quick succession.
An artist illustration of the mobile launcher with umbilical lines set up on the tower and connected to NASAs Space Launch System rocket and Orion spacecraft. Credit: NASA
Throughout propellant filling operations earlier in the day, launch controllers experienced a hydrogen leakage in the fast disconnect that attaches an umbilical from the tail service mast on the mobile launcher to the rockets core phase. The team attempted to repair the leakage by warming the quick disconnect and after that chilling it back down to straighten a seal, but their efforts did not repair the issue.
Launch controllers then established a plan to mask data associated with the leak that would set off a hold by the ground launch sequencer, or launch computer system, in a genuine launch day situation, to permit them to get as far into the countdown as possible. The time needed to establish the plan needed prolonged hold time throughout the countdown activities, however they were able to resume with the final 10 minutes of the countdown, called terminal count. During the terminal count, the teams carried out numerous critical operations that need to be accomplished for launch including changing control from the ground launch sequencer to the automated launch sequencer controlled by the rockets flight software, and crucial step that the group wanted to achieve.