Teams have rescheduled the return of the Space Launch System rocket and Orion spacecraft to the Vehicle Assembly Building (VAB) at NASA’s Kennedy Space Center to Friday, July 1 due a concern with the condition of the crawlerway that leads from Launch Pad 39B to the VAB. First motion is now planned for 6 p.m. EDT.

This afternoon, teams conducted a series of conditioning efforts driving the massive transporter up and down the slope leading to the launch pad. The inclined pathway must be precisely level with an even distribution of the rocks that make up the crawlerway in order to support the load of the mobile launcher and rocket that it will carry.

Teams will continue grating, or sifting, the crawlerway overnight and the rocket and spacecraft remain in a safe configuration.

NASA will roll the Space Launch System rocket and Orion spacecraft for the Artemis I mission from launch pad 39B to the Vehicle Assembly Building (VAB) at the agency’s Kennedy Space Center in Florida beginning Thursday, June 30. 

First motion for the rocket and spacecraft atop the mobile launcher is expected to occur at 8 p.m. EDT today. The 4-mile trek atop the crawler transporter from the launch pad to the VAB will take approximately 8-12 hours. The journey previously was expected to begin just after midnight on July 1 but was moved up by several hours due to forecasted weather in the area. Teams will continue monitoring weather in the area and the start of the roll is subject to change. 

Teams completed the wet dress rehearsal test campaign for Artemis I on June 20 and have configured the rocket and spacecraft for return to the VAB. Once there, teams will replace a seal on the quick disconnect of the tail service mast umbilical to address a liquid hydrogen leak detected during the rehearsal along with final servicing and checkouts. NASA plans to return the mega Moon rocket to the pad for launch in late August and will set a specific target launch date after replacing hardware associated with the leak. 

A live feed of the rocket’s arrival to the VAB will be available on the KSC Newsroom YouTube Channel. 

Over the weekend, teams successfully conducted a test of the thrust vector control system on each of the twin solid rocket boosters of the Space Launch System for Artemis I while the rocket remains at Launch Pad 39B. The test was a follow-on to the wet dress rehearsal test campaign, which was completed last week.

During the test, engineers activated the booster hydraulic power units (HPU), which are hydrazine-powered turbines attached to hydraulic pumps that provide pressure to move the hydraulic actuators that gimbal the booster nozzles. The test verified the normal startup, operations, and shutdown of a fully integrated thrust vector control system, which controls the movement of the nozzles on each of the boosters during ascent. It also verified the rocket’s avionics system using both flight and ground software for the first time. The boosters were not ignited during the test.

The test was part of the objectives that were not completed during the wet dress rehearsal demonstration, as the rehearsal test ended at T-29 seconds during the terminal countdown. During launch, the automated launch sequencer gives the command to activate the HPUs at T-28 seconds.

Teams will drain the hydrazine from the boosters and are in the process of configuring the rocket and Orion spacecraft for their return to the Vehicle Assembly Building (VAB) at the end of the week. Once there, teams will replace a seal on the quick disconnect of the tail service mast umbilical to address a liquid hydrogen leak detected during the rehearsal. NASA plans to return the mega Moon rocket to the pad for launch in late August and will set a specific target launch date after replacing hardware associated with the leak.

A live feed of the rocket departing the launch pad and arrival at VAB will be available on the KSC Newsroom YouTube Channel.