Due to engine cooling problems, one day after the first launch of NASA’s heavy space launch system rocket, the mission manager announced that they would launch again on Saturday.
At the same time, engineers will work out the details of a “go / no go” plan in case they face problems similar to forcing them to scrub on Monday.
Saturday’s two-hour launch opportunity will open at NASA’s Kennedy Space Center in Florida at 2:17 p.m. EDT (11:17 a.m. EDT). If all systems can operate normally, the launch will mark the beginning of NASA’s Artemis 1 mission, which is an unhumidified test flight aimed at laying the foundation for sending astronauts to the moon in the mid-1920s.
Saturday’s attempt will change some aspects of the countdown. For example, the task manager plans to perform an engine cooling procedure at an early stage of the refueling process. The program involves “draining” part of the rocket’s liquid hydrogen fuel to cool the core stage’s four main engines to an ideal temperature of minus 420 degrees Fahrenheit.
When the cooling system was tested during the “green operation” at NASA Stennis Space Center in Mississippi in March, the program was successfully carried out early in the refueling process. But when a hydrogen leak occurred late in the countdown on Monday, a sensor showed that one of the engines – Engine 3 – was not cold enough.
Mission management decided to replicate the procedures used by Stannis.
John Honeycut, NASA SLS project manager, said that the problem might be the sensor, not the hydrogen emission system itself.
“We understand the physical properties of hydrogen,” he told reporters. “The working mode of the sensor does not match the actual situation.”
Honicart said he and his team are working on a plan to verify that the engine is properly cooled based on broader data. He said that the research team would prefer to avoid entering the rocket directly and working on the sensors, which may require rolling the rocket back from the launch pad.
“With the help of the team, what I plan to do is to put us in a situation where we can use the data we obtained today to get the data we need, that is, we have cooled the engine properly and started to fly,” honicart said.
The engineer will also investigate other problems that occurred during the countdown on Monday, such as the leakage of the exhaust valve in the inter-bank area of SLS. Launch director Charlie Blackwell Thompson said the leak was clearly the result of troubleshooting the hydrogen emission system.
Weather forecasters say there is a 40% chance that the weather for Saturday’s launch is acceptable. Blackwell Thompson said that if the weather forces another delay, it may try again at the end of the Labor Day weekend on Monday.
For the Artemis 1 mission, SLS rocket will launch an unmanned Orion spacecraft for test flight, fly around the moon, and then return to the earth to splash down in the Pacific Ocean. NASA’s current plan requires Artemis 2 to launch a manned flight around the moon in Orion in 2024, and Artemis 3 to send astronauts to the lunar surface within the time frame of 2025-2026.