NASA Will Attempt Megarocket Launch Rehearsal in June

A fourth attempt to complete a full-fledged launch rehearsal of NASA’s Space Launch System has been slated for June. NASA’s ground teams say they’ve resolved a batch of technical issues that prevented the practice session from happening in April. For this next test, they will fill the giant rocket with super-cooled propellant and rehearse a full countdown.

Speaking to reporters today, Cliff Lanhman, senior vehicle operations manager at NASA, said the call to stations for rollout will happen at 6:00 p.m. ET on June 5, with Crawler-Transporter 2 making its first motion at midnight on June 6. The loading of cryogenic propellants will happen no earlier than June 19, Lanhman said, adding that Florida’s tumultuous summer weather (i.e. thunderstorms) could change that.

The giant rocket was transported back to the Vehicle Assembly Building at Kennedy Space Center, Florida, on April 26, following three failed attempts to perform a full-blown wet dress rehearsal. A steady stream of technical issues and challenges prevented the ground team from filling the rocket with cryogenic propellant, a list of issues that included a faulty upper stage helium check valve, a hydrogen leak on the tail service mast umbilical, and inadequate delivery of gaseous nitrogen as supplied by the third-party vendor Air Liquide, among other, seemingly mild problems.

The inaugural launch of SLS will kickstart the Artemis era, in which NASA seeks to build a sustainable human presence on and around the Moon. SLS is key to Artemis, as it will also assist in the construction of Gateway—the first space station in orbit around the Moon. NASA also plans to use the giant rocket for future missions to Mars, which could happen in the late 2030s or early 2040s.

During today’s press conference, Lanhman said the technical issues that affected the previous attempts at the wet dress were resolved, including a replacement of the faulty helium check valve, a redesign of the umbilical boot, and the addition of leak detectors. Teams have also tested the upgraded gaseous nitrogen system, he said.

Looking ahead to the wet dress, Tom Whitmeyer, deputy associate administrator for common exploration systems development at NASA, said the rocket is a “very robust” and “straightforward vehicle,” but that cryogenics tends to complicate things. “It’s a process,” he said at the briefing, as the ground teams have “got to learn how the rocket is behaving” and take it “one step at a time.”

Whitmeyer also confirmed that NASA is looking at August for the Artemis 1 launch. As it stands, the August launch periods will run until August 10 (excluding August 1, 2, and 6) and then from August 23 to September 6 (excluding August 30, 31, and September 1). For this inaugural mission, SLS will launch an uncrewed Orion capsule on a round-trip mission to the Moon.

More: NASA’s Artemis Moon Landing Program: Launches, Timeline, and More.