Fourth Wet Dress Rehearsal pushes Artemis I towards Launch

Boeing and NASA teams completed a robust practice countdown – also known as Wet Dress Rehearsal (WDR) – on Monday, June 20, that saw the Artemis I launch vehicle fueled and drained in a test of timing and mechanisms for the massive rocket and spacecraft. Artemis I will be the first mission of NASA’s lunar exploration program and will be an unpiloted test flight of the launch vehicle and the Orion spacecraft. The WDR activities mark the last phase of integrated testing and put the fully stacked Space Launch System (SLS) on the path to launch.

During this week’s WDR, the SLS core stage and upper stage were loaded with hundreds of thousands of gallons of supercold liquid hydrogen (LH₂) and liquid oxygen (LOX). Controllers also ran through the mission checklist, most of which had not been performed at Launch Complex 39-B since the space shuttle era. As minor technical hurdles were realized, the team opted to work the rocket as far through the launch countdown as they could without raising risks to the vehicle and to further demonstrate readiness.

Speaking publicly on Tuesday, NASA officials said the test run was successful with the test concluding at T-29 seconds – a few seconds prior to the original plan but deep into the final phase of the countdown.

“This Wet Dress Rehearsal is an important exercise because it gives the team confidence in the machinery of the rocket and spacecraft and how all the systems will perform together on launch day and during flight,” said John Shannon, Boeing’s VP and program manager for the Space Launch System.

NASA will survey the data from this Wet Dress Rehearsal and provide next steps in advance of the Artemis I launch, which will launch the Orion spacecraft on a path to orbit the Moon and demonstrate the safety of the mission architecture. A later mission, Artemis II, will take astronauts on a similar flight around the Moon in the Orion spacecraft. The Artemis III mission is slated to land astronauts on the Moon.

Learn more about Artemis I on our mission website and follow @BoeingSpace on Twitter for real-time mission updates.

By: Steven Siceloff & Taylor Rine