NASA’s mobile launcher that will carry the Space Launch System (SLS) and Orion spacecraft for Artemis I is on the road again. The Exploration Ground Systems and Jacobs teams rolled the mobile launcher, atop crawler-transporter 2, out of the Vehicle Assembly Building for its slow trek to Launch Pad 39B at Kennedy Space Center in Florida on Oct. 20.
The roll began just after midnight, and the mobile launcher arrived at the top of the pad Tuesday morning. This trek to the pad will help prepare the launch team for the actual wet dress rehearsal and launch of SLS and Orion on Artemis I next year. The wet dress rehearsal is when SLS and Orion will be rolled out to the pad atop the mobile launcher to practice fueling operations a couple months before launch. The last time the mobile launcher was rolled to the pad was in December 2019.
During its two-week stay at the pad, engineers will perform several tasks, including a timing test to validate the launch team’s countdown timeline, and a thorough, top-to-bottom wash down of the mobile launcher to remove any debris remaining from construction and installation of the umbilical arms.
“While these tasks have been rehearsed individually, the return to Pad 39B allows the team to perform this sequence altogether,” said Charlie Blackwell-Thompson, Artemis launch director.
To begin, technicians will lower the engine service platform that is under the core stage RS-25 engines from the mobile launcher and move it to the launch position. The platform allows access to the engines for routine work or inspections. Engineers and technicians will rehearse a timely completion of removing platforms used to access SLS core stage engines. They will position both side flame deflectors in the flame trench and raise the extensible columns to launch configuration that are critical to support an on-time launch. The extensible columns are designed to provide extra support to the mobile launcher at liftoff, when the loads are the greatest. The team also will perform preparations of mobile launcher umbilical arms along with other mobile launcher and pad subsystems.
“During the Artemis launch countdown, this work will be performed prior to tanking,” Blackwell-Thompson said. “As part of this demonstration, the team will exercise the ground hardware in order to determine the timing of these critical elements.”
During its time at the pad, the mobile launcher also will receive a bath.
“The wash down will reduce the risk to the SLS/Orion during launch,” said Cliff Lanham, EGS flow director. “Some of the debris are inaccessible without using high-pressure water, available at the pad, to get into hard-to-reach areas.”
To accomplish the wash down, the team will use the mobile launcher’s fire protection system, which has hoses on each level and the deck. The high-pressure flow rate will wash debris into the flame trench, industrial wastewater retention tanks, and percolation ponds. Lanham said this is an added safety measure, in addition to the walk downs performed prior to launch.
While at the pad, the mobile launcher’s fire suppression system also will be recertified. The last certification was in December 2019 and is due before launch in November 2021.
Artemis I will test the Orion spacecraft and SLS as an integrated system ahead of crewed flights to the Moon. Under the Artemis program, NASA will land the first woman and the next man on the Moon in 2024.