The two-hour launch window opens at 2:17 p.m. ET on September 3.
After the launch was called off on Monday morning, the launch team spent the rest of the day evaluating the data collected during the attempt. Mission managers shared an update Tuesday evening.
The Artemis I kit, which includes the Space Launch System rocket and Orion spacecraft, is still on Launchpad 39B at the Kennedy Space Center in Florida.
One of the rocket’s four RS-25 engines, identified as Engine No. 3, was unable to reach the appropriate temperature range required to start the engine on takeoff.
Engines must be thermally conditioned before super-cooled propellant flows through them before takeoff. To prevent the engines from experiencing any temperature shocks, the launch control units increase the pressure of the liquid hydrogen tank in the primary stage to send a bit of liquid hydrogen to the engines. This is known as “bleeding.”
Liquid hydrogen has a temperature of 423 degrees Fahrenheit (minus 252 degrees Celsius).
Engine 3 was likely about 30 to 40 degrees warmer than the other engines, which came to about 410 degrees Fahrenheit (minus 245 degrees Fahrenheit), said John Honeycutt, Space Launch System program manager at NASA’s Marshall Space Flight Center in Alabama. .
The task managers suspected that the engine issue 3 was actually a problem with the bleed system, not the actual engine. Honeycutt said a faulty sensor could provide an incorrect engine temperature reading.
“The way the sensor behaves doesn’t fit with the physics of the situation,” Honeycutt said.
The team plans to start bleeding 30 to 45 minutes earlier in counting down what happened on Monday and monitoring the engine temperature while it bleeds.
“When trying yesterday, we said if we couldn’t thermally condition the engines, we wouldn’t launch,” Sarafin said. “This is the same position we go to on Saturday.”
Removing and replacing the sensor would be difficult at the launch pad, so the only alternative is to return it to the vehicle assembly building for maintenance, said Charlie Blackwell Thompson, Artemis launch manager in NASA’s Earth Exploration Systems Program.
Several other issues, such as storms, a leak on the 8-inch line used to fill and drain liquid hydrogen to the rocket’s core stage and hydrogen leakage from a relief valve in the core stage’s intertank also caused delays on Monday morning preventing takeoff during Monday. – Hour launch window.
“We agreed on what was called the first option, which was to change the loading procedures operationally and start cooling our engine early.” “We’ve also agreed to do some work on the platform to address the leak we saw in the secret hydrogen tail service mask,” said Mike Sarafin, Artemis mission manager, NASA Headquarters.
The current forecast for Saturday includes a chance of showers and thunderstorms in the morning and early afternoon hours, so the launch team will be watching the forecast closely, said meteorologist Mark Burger, the launch meteorologist for the US Space Force’s 45th Weather Squadron.
There is a 60% chance of a weather violation occurring during the launch window, Berger said.
There is still a backup chance for the Artemis I mission to launch on September 5th as well.
The Artemis I mission is just the beginning of a program aimed at returning humans to the Moon, and eventually landing manned missions on the surface of Mars.
Correction: an earlier version of this false storyDr meteorologist Mark Burger’s name.
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