NASA is getting ready to interchange a defective seal linked to a hydrogen leak that resulted within the second scrubbed launch try of SLS on Saturday. The repairs will occur on the launch pad, which is right from a testing perspective, however NASA nonetheless must cart the jumbo rocket again to the meeting constructing to fulfill security necessities.

Technicians will exchange a seal on the short disconnect, an interface that joins the liquid hydrogen gasoline line on the cellular launcher to the Space Launch System core stage, in accordance with a short NASA statement. The groups may also test plate coverings on different umbilicals to rule out hydrogen leaks at these places. “With seven main umbilical lines, each line may have multiple connection points,” NASA defined.

NASA is making an attempt an uncrewed mission to the Moon and again, in preparation for a human lunar touchdown later this decade. But during the early phases of the launch try on September 3, an inadvertent command briefly raised the strain throughout the system, probably damaging some elements. An unmanageable hydrogen leak resulted within the scrub—the second in per week. The earlier scrub, on Monday, August 29, was additionally marred by a hydrogen leak, although engineers had been in a position to resolve it. Ultimately, it was a defective sensor that doomed the first launch try.

The unflown SLS rocket stays in a secure configuration, standing tall on Launch Pad 39B at Kennedy Space Center in Florida. NASA is searching for to launch the Artemis 1 mission, through which the rocket will ship an uncrewed Orion spacecraft on a journey round the Moon and again. The first launch interval, which ran from August 23 to September 6, has ended, forcing a pause within the motion. The area company should now put together the 322-foot-tall (98-meter) rocket for the third Artemis 1 launch try, the date of which has not but been introduced.

Technicians are planning to arrange a brief enclosure across the base of the rocket to guard the {hardware} from the Florida climate. A good thing about working immediately on the pad is that engineers will have the ability to check the repair below cryogenic circumstances. During launch preparations, liquid hydrogen will get pumped via the system at ultra-cold temperatures reaching -423 levels Fahrenheit (-253 levels Celsius). This, plus the added excessive strain, has the impact of contracting and warping elements, which may result in undesirable and harmful leaks, significantly round seals.

As a propellant, hydrogen is environment friendly however notoriously troublesome to reign in. Hydrogen leaks had been an all-too-frequent supply of scrubs in the course of the Space Shuttle period, and now SLS, which is likewise powered by a liquid hydrogen and liquid oxygen combination, seems to be affected by the identical technical hardship.

Engineers mulled returning SLS to the close by Vehicle Assembly Building (VAB) for the required repairs however opted as an alternative to work on the pad. The VAB would’ve offered a extra managed setting to work in, however with out the power to duplicate the specified cryogenic circumstances for testing (assessments contained in the VAB need to be run at ambient temperatures). “Performing the work at the pad also allows teams to gather as much data as possible to understand the cause of the issue,” NASA added.

SLS will doubtless need to return to the VAB, repair or no repair. The Eastern Range, a department of the U.S. Space Force, requires periodic certification of the rocket’s flight termination system. NASA already acquired a waiver that prolonged certification from 20 to 25 days, however it’s not clear if the area company will request a second waiver, which might be irregular. The Eastern Range oversees launches from Kennedy Space Center and Cape Canaveral Space Force Station, and works to make sure the general public’s security.

At a press briefing on Saturday, Mike Sarafin, Artemis mission supervisor, stated “it’s not our decision—it’s the Range’s decision.” He added {that a} waiver from the Range might preserve the rocket on the pad, “but that’s not likely.” So, below the Eastern Range restrictions, and till we hear in any other case from NASA a few second waiver, the rocket should return to the VAB previous to the subsequent launch interval.

A 3rd launch try in late September or early October stays a distant risk. The subsequent interval opens on September 19 and closes on October 4, with no alternatives to launch on September 29 and 30. For this to work, nonetheless, NASA must full its newest repair, run assessments, cart SLS again to the VAB for recertification (which entails a really brief confidence check), after which cart it again to the launch pad. It’s doable, however floor groups should haul ass to make this occur.

Failing this, the third launch interval opens on October 17 and closes on October 31, with launch exclusions on October 24, 25, 26, and 28. Two different durations, one in November and one in December, exist throughout the present calendar yr.

There’s nonetheless loads of time for SLS to launch in 2022, however it all is determined by how shortly engineers can get a deal with on this complicated system. SLS is essentially the most highly effective rocket that NASA has ever constructed and is a key part of the area company’s Artemis program, which seeks a sustained and extended human presence at and across the Moon.

More: What to Know About Lunar Gateway, NASA’s Future Moon-Orbiting Space Station.