Artemis I postponed due to engine bleed issues

The rocket was planned to blast off during a two-hour launch window on 29th August, beginning at 8.33 EDT (13.33 BST). In what was set to be a historic moment for the sector, the uncrewed Orion spacecraft would travel thousands of miles beyond the Moon in a 42-day mission, next time with astronauts on board for Artemis II.

Engineers discovered an issue conditioning one of the RS-25 engines on the bottom of the Space Launch System (SLS)’s core stage after beginning overnight loading of liquid oxygen and liquid hydrogen into the core stage tanks and interim cryogenic propulsion stage.

NASA reported that its launch controllers condition the engines by increasing pressure on the core stage tanks to ‘bleed’ some of the cryogenic propellant to the engines. This is required to get them to the necessary temperature range for lift-off.

Engineers had to troubleshoot an issue with Engine 3 not being properly conditioned through the bleed process. They were also reported to be assessing a crack in the thermal protection system material on one of the flanges on the core stage.