The 70-minute launch window opens at 11:37 am ET and the Space Launch System rocket and the Orion spacecraft continue to sit on the Kennedy Space Center launch pad in Florida.
Concerns about the forming weather system in the Caribbean have put weather conditions only 20% favorable for a launch. The current tropical depression path puts the storm on track to hit Cuba and Florida early next week.
Given the uncertainty about the storm’s track, intensity, and arrival time, Artemis’ team will use the most recent data to make decisions about the storm, said Mike Bolger, manager of NASA’s Exploration Ground Systems program.
The Artemis team is closely monitoring the weather and will make a decision on Saturday.
Launch constraints require that the Artemis I mission not fly through precipitation. Launch constraints are designed to avoid natural and rocket-triggered lightning to flying rockets, which could cause damage to the rocket and endanger public safety, according to the Space Force.
A rocket-triggered lightning bolt forms when a large rocket flies through a sufficiently strong atmospheric electric field, so a cloud that doesn’t produce natural lightning could still cause rocket-triggered lightning, according to the Space Force.
If the rocket stack needs to be returned to the Kennedy Space Center Vehicle Assembly Building, the process could take several days.
The rocket stack can remain on the pad and withstand winds of up to 85mph (74.1 knots). If the pile is to re-enter the building, it can withstand sustained winds of less than 46 miles per hour (40 knots), Bolger said.
Evaluation of crucial data
Meanwhile, the Artemis team is encouraged after “a very successful tanking test” and “the rocket looks good for upcoming launch attempts,” said John Blevins, SLS chief engineer at NASA’s Marshall Space Flight Center in Huntsville, in Alabama.
The crucial refueling test for the mega lunar rocket met all of its targets on Wednesday, despite two separate hydrogen leaks occurring.
The purpose of the cryogenic demonstration was to test the replaced seals and use updated loading procedures, “gentler and gentler” than the supercool propellant the rocket would experience on launch day.
NASA engineers detected a leak of liquid hydrogen during the test that had “the same signature” as a leak that prevented the September 3 launch attempt. However, their troubleshooting efforts allowed the team to manage the loss.
The team was able to completely fill the central stage with liquid oxygen and liquid hydrogen. They also completed an engine bleed test, which conditions the four engines and lowers their temperature before launch. (The mission team canceled the first Artemis I launch attempt on Aug.29 largely due to an issue with a faulty sensor that occurred during the bleeding.)
A hydrogen leak detected on the 4-inch quick disconnect line for the engine bleed exceeded the 4% threshold during a pre-pressurization test. This quick disconnect line carries liquid hydrogen out of the engines after they have passed through the engines and cooled them. But the loss rate went down on its own.
Additionally, the Artemis team received Space Force approval for the launch attempt on September 27 and a backup date of October 2.
The Space Force oversees all rocket launches from the east coast of the United States, including the NASA launch site in Florida, and that area is known as the Eastern Range. Range officers are tasked with making sure there is no risk to people or property with any launch attempt.
After receiving detailed data from NASA, the Space Force issued a waiver for the launch dates.
The inaugural mission of the Artemis program will kick off a phase of NASA space exploration that intends to land several crews of astronauts in previously unexplored regions of the moon – in the Artemis II and Artemis III missions, scheduled for 2024 and 2025 respectively – and eventually deliver manned missions to Mars.