It’s been a bumpy road for NASA engineers as they try to get their enormous moon-bound Space Launch System ready for liftoff in the next few of months. Launching the world’s most powerful rocket at Kennedy Space Center in Florida on March 17 was a major step toward the Artemis program’s first lunar trip later this year. Since then, engineers have performed a slew of system checks on the massive rocket, but they have yet to pass the last test, a practise countdown known as the “wet dress rehearsal test.”
A malfunctioning helium check valve and a liquid hydrogen leak were the main causes of the test countdown being pushed back many times during the trial. SLS and Orion crew capsules were safely returned to NASA’s Vehicle Assembly Building, where engineers could do any necessary rocket surgery they deemed necessary over the weekend. Even if they return to the pad next week to complete the countdown test, the scheduled early June launch of the first Artemis trip around the moon may be postponed.
“The huge moon rocket is still functioning really well,” he said. The only serious problem we’ve encountered so far is a single check valve. When asked about the rocket during a news conference today, NASA associate deputy administrator Tom Whitmeyer said: “We’re really proud of the rocket. “However, we still have some work to do.”
Because NASA doesn’t want to risk losing their most costly rocket or the first flight of Artemis, these safeguards aren’t surprising. Mike Sarafin, the Artemis mission manager, said at a news conference earlier this month that “it boils down to what we deem to be the appropriate amount of risk.”
It was on April 1 that the rocket was taken from the assembly facility to Launch Complex 39B using a gigantic crawler. After connecting the rocket’s electrical and pressurisation systems and loading fuel into the white boosters on each side, senior NASA test director Jeff Spaulding and his crew got to work. After that, they began to fill the massive orange fuel tank with 700,000 gallons of supercooled liquid hydrogen and liquid oxygen, both of which had been cooled to a chilly -423 degrees Fahrenheit. In the phrase “wet dress rehearsal test,” that’s what they mean by “wet.” They wanted to replicate the whole countdown sequence to just before the core stage’s RS-25 engines were activated—the closest thing to an actual launch without firing them up.
Instruments, pressures, temperatures, and valves were constantly monitored by Spaulding and his colleagues to ensure that all systems were operating within acceptable specifications. In the days preceding up to the rehearsal, he had remarked, “If it turns out they’re a bit outside of the limitations, that’s what we want to know now—if there’s something we need to modify or adjust.”
As a result of the analysis, various changes were necessary. Lightning bolts struck the towers around the rocket on April 2, delaying the procedure for the second time. On the next day, NASA personnel found issues with the launch tower fans and their backups, according to Artemis launch director Charlie Blackwell-Thompson. The mobile launcher, the towering building adjacent to the rocket, is protected from dangerous gases thanks to these fans. It took some time to fix the fan problem because of it.