Space Launch System rocket returns to Pad 39B for critical test

NASA's Space Launch System rocket returns to Launch Complex 39B for a planned wet dress rehearsal later this month. Credit: Theresa Cross / Spaceflight Insider

NASA’s Space Launch System rocket returns to Launch Complex 39B for a planned wet dress rehearsal later this month. Credit: Theresa Cross / Spaceflight Insider

NASA’s giant Space Launch System rocket is back at Launch Complex 39B at Kennedy Space Center in Florida where it will once again attempt a full wet dress rehearsal in advance of the Artemis 1 Moon mission later this summer.

The wet dress rehearsal is the final milestone before any launch attempt can occur for Artemis 1. This requires NASA to load and drain propellant into the rocket’s tanks, as well as organize and conduct a full launch countdown to verify chronological procedures and logistics that are compulsory for a successful liftoff.

The Space Launch System rocket sits atop Launch Complex 39B. Credit: Theresa Cross / Spaceflight Insider

First movement out of the space agency’s Vehicle Assembly Building occurred at 12:10 a.m. EDT (4:10 UTC) June 6, 2022. Using a crawler-transporter, the SLS atop the Mobile Launcher arrived at the pad at around 8:20 a.m. where it was secured and readied for the test, currently planned for later this month.

This will be the space agency’s second go at the test. During the month of April, NASA engineers attempted to perform the fueling and countdown test following an initial rollout in March. However, various problems, including a failed upper stage check valve and leaky tail service mast umbilical, prompted the agency to return the rocket to the VAB.

Engineers addressed the issues the rocket encountered during the April attempts at the wet dress rehearsal. During investigations into the vehicle inside the VAB, NASA teams were able to identify and accomplish a list of repairs and replacements.

The successful execution of improvements and developments included assessing the leaking hydrogen system at the tail service mast umbilical, replacing the interim cryogenic propulsion stage gaseous helium system check valve with supporting hardware, and the modification of the ICPS umbilical purge boots were all performed while under-roof at the VAB.

Prior to this second rollout, the hatches and access points on the crew module were secured and engineers installed rain gutters on the crew access area to prevent moisture from leaking into SLS rocket while at the launch pad.

NASA is currently targeting no earlier than June 19 for its next attempt at the wet dress rehearsal. Should all go according to plan, the agency is then expected to roll the rocket back to the VAB to ready it for the Artemis 1 mission.

Artemis 1 is expected to fly as early as late July or August. It will send an uncrewed Orion spacecraft on a trip to a distant retrograde orbit around the Moon before returning to Earth several weeks later.

The Space Launch System during sunrise on June 7. Credit: Theresa Cross / Spaceflight Insider