NASA’s Artemis program aims to land astronauts on the Lunar South Pole by 2025. It has been roughly half a century since humanity last set foot on the lunar surface. NASA has worked with more than 1,100 companies across the United States to develop the powerful Space Launch System (SLS) rocket and Orion spacecraft, designed to launch astronauts to lunar orbit. The agency also contracted SpaceX to develop a lunar-optimized Starship Human Landing System (HLS) to land astronauts on the Moon’s surface. NASA has a flight plan to utilize both launch systems, outlined in the graphic below. Orion is designed to dock with Starship HLS in lunar orbit to land astronauts on the Moon.

To prepare for a crewed lunar mission NASA will first conduct the Artemis I mission, an uncrewed demonstration flight test of the SLS/Orion vehicle that the agency plans to conduct this year. By 2023, NASA plans to launch the Artemis II mission; It will be the first crewed demonstration flight of SLS/Orion around the Moon. SpaceX will perform the first orbital flight test of Starship this year and the first demonstration flights around the Moon until 2023. After those demo missions are successful NASA and SpaceX will collaborate to conduct the Artemis III mission, which will land a pair of astronauts on the lunar surface.

NASA attempted to launch the long-awaited Artemis I mission this week. On August 29, the agency fueled the 322-foot (98-meter) SLS rocket with nearly 1 million gallons of fuel to launch Orion towards lunar orbit from Launch Pad-39B at the Kennedy Space Center in Florida. The SLS RS-25 engines are fueled with liquid hydrogen (LH2) and liquid oxygen (LOX). The mission was scrubbed due to an engine issue that arose before liftoff. During the launch attempt, engineers were unable to "chill down" the rocket's four RS-25 engines to minus 420°F (degrees Fahrenheit); three of the engines had higher temperatures than the other engine. There was also a hydrogen leak on the "purge can", a component of the tail service mast umbilical quick disconnect. Engineers tried to manage the leak by manually adjusting propellant flow rates.

NOW: @NASAArtemis teams provide an update on the status of the #Artemis I flight test to the Moon following the Sept. 3 launch attempt. https://t.co/1MoquGPIgs

— NASA (@NASA) September 3, 2022

SLS engineers assessed the issue for around four days and they attempted a second launch this morning, September 3rd. “After standing down on today’s Artemis I launch attempt when engineers could not overcome a hydrogen leak in a quick disconnect, an interface between the liquid hydrogen fuel feed line and the Space Launch System rocket, mission managers met and decided they will forego additional launch attempts in early September,” said NASA representatives. The mission was called off at around 11:17 a.m. ET.

During tanking of the #Artemis I mission, a leak developed in the supply side of the 8-inch quick disconnect while attempting to transfer fuel to the rocket. Attempts to fix it so far have been unsuccessful. Stand by for updates. https://t.co/6LVDrA1toy

— NASA (@NASA) September 3, 2022

“During today’s launch attempt, engineers saw a leak in a cavity between the ground side and rocket side plates surrounding an 8-inch line used to fill and drain liquid hydrogen from the SLS rocket. Three attempts at reseating the seal were unsuccessful,” explained NASA, “While in an early phase of hydrogen loading operations called chilldown, when launch controllers cool down the lines and propulsion system prior to flowing super cold liquid hydrogen into the rocket’s tank at minus 423 degrees F, an inadvertent command was sent that temporarily raised the pressure in the system. While the rocket remained safe and it is too early to tell whether the bump in pressurization contributed to the cause of the leaky seal, engineers are examining the issue.” 

Due to the complex orbital mechanics of arriving to the Moon, the next potential launch date is until Monday, September 5 at 5:12 p.m. ET, but if SLS is ready for liftoff in time. If it is not, SLS will be transported back to the Vehicle Assembly Building located near Launch Pad-39B where engineers will inspect the rocket’s engines. NASA Administrator Bill Nelson said that if engineers determine that the rocket needs repairs, the launch will slip to mid-October. “We'll go when it's ready. We don't go until then, and especially now on a test flight," said Nelson during the broadcast after the scrub. "This is part of the space business."

"We'll go when it's ready." NASA Administrator @SenBillNelson remarks on the Sept. 3 launch attempt of the #Artemis I flight test to the Moon. Updates are expected from the team as early as 4pm ET (20:00 UTC). https://t.co/dMVnvEQcfC pic.twitter.com/ClBhVRexLs

— NASA (@NASA) September 3, 2022

Featured Image Source: NASA