Artemis II Returns To Hangar

CAPE CANAVERAL—The Artemis II Space Launch System (SLS) rocket and Orion spaceship began the slow crawl back to their processing hangar Feb. 25, ending a 39-day test period at Kennedy Space Center Launch Complex 39B.

After a pair of countdown dress rehearsals—each lasting two days and including 700,000-gallon cryogenic fuelings—NASA was preparing to launch the crewed Artemis II flight test between March 6-11.

But a day after completing the second practice run, the helium purge and pressurization system aboard the SLS upper stage malfunctioned. Troubleshooting and repairs could not be done at the launchpad due to access issues, and the SLS’ crawler-transporter began the 4 mi., 12-hr. trek to the Vehicle Assembly Building at 9:38 a.m. EST Feb. 25.

NASA fixed a similar issue with the SLS Interim Cryogenic Propulsion Stage (ICPS) helium system ahead of the November 2022 uncrewed Artemis I mission, which marked the debut of the SLS rocket.

In that case, the system failed during wet dress rehearsal due to a faulty check valve aboard the vehicle.

Engineers have not yet identified the cause of the current problem, but troubleshooting is focused on a filter in the umbilical between ground equipment and the flight hardware; a failed quick-disconnect umbilical interface; and/or a failed check valve.

The ICPS, built by United Launch Alliance and derived from the upper stage of the now-retired Delta IV Heavy, contains bottles of helium to pressurize its tanks and purge its single Aerojet Rocketdyne RL10 engine and propellant lines with the inert gas to minimize fire risks. 

NASA is hoping to return the stack to the pad mid-March in time to make an early April launch window, but that would require a very quick turnaround. In addition to diagnosing and repairing the ICPS helium system, technicians plan to service the ICPS and SLS Flight Termination System batteries, which would support launch attempts later this spring.

The next window that meets the mission’s Earth-Moon orbital phasing, lighting and other requirements opens April 1 and closes April 6. The following launch window opens April 30.

Artemis II is a 10-day crewed flight test of Lockheed Martin’s Orion spacecraft. Following a systems checkout in high Earth orbit, Orion is expected to slingshot itself onto a trajectory that circles some 4,600 mi. past the Moon and then returns to Earth. The Artemis II crew—Reid Wiseman, Victor Glover, Christina Koch and Canada’s Jeremy Hansen—are poised to become the first people to travel to the Moon since Apollo 17 in 1972.