Why did NASA wave off Artemis 1's launch attempt?
What's the story
August 29 was supposed to be a historical day for NASA. It was the highly-anticipated Artemis 1's lift-off day.
However, things didn't go as planned and the space agency called off the launch due to an issue with the SLS (Space Launch System) rocket.
September 2 will be the next probable launch date. Now, let's take a look at what went wrong on Monday.
Context
Why does this story matter?
NASA's Artemis mission is a significant chapter in mankind's space adventures. However, some setbacks have delayed the beginning of the journey.
Hundreds of thousands of people who were waiting for the launch were left disappointed. What most of them don't know is that such setbacks are common for a mission of this magnitude.
Sooner than later, we will see the SLS rocket lifting off.
Main reason
One of the engines of SLS faced a temperature-related issue
On Monday, Artemis 1's countdown clock was put on hold by NASA 40 minutes before the launch (T-40). An issue encountered in one of the four RS-25 engines in the SLS rocket's core stage was behind the delay.
Launch controllers were unable to chill Engine No. 3 before flowing cryogenic liquid hydrogen and liquid oxygen.
The other three engines had passed the test.
Thermal priming
Engine No. 3's temperature didn't come down to 5-degrees Celsius
Engines in the core stage are conditioned by increasing the pressure on the core tanks to bleed some cryogenic propellant to the engines to get them to proper temperatures.
The Artemis 1 team wasn't able to chill Engine No. 3 to about 40-degrees Fahrenheit (5-degrees Celsius).
This process is important to prevent a shock when the engines start burning their propellants.
Cause
The issue is with the 'bleed system' that conditions engines
It is unclear what caused the issue. "Right now, the indications don't point to an engine problem," said Artemis mission manager Mike Sarafin.
He said that the engine problem lies in the 'bleed system' that thermally conditions the engines with super-cold propellant.
The Artemis 1 team took the rest of Monday off to prepare for a 96-hour cycle to fix the issue.
Alternative dates
What is next for Artemis 1?
Despite failing to launch on August 29, Artemis 1 mission is still on track for a launch this week itself.
The next penciled alternative flight date is September 2. If the team is not able to fix the engine issue by then, the next opportunity will come on September 5.
After that, the next launch window will open on September 19.
Information
Weather will play a huge part in Artemis 1's launch chances
Even if the technical issues of Artemis 1 are fixed, the launch of the rocket is still not guaranteed. The mission will need the help of weather as well. Early weather forecasts predict only a 40% chance of good weather for a Friday launch.
Caution
The rocket will not fly until it's ready: NASA
NASA is highly cautious about the launch of SLS. "This is a brand-new rocket. It's not going to fly until it's ready," said NASA Administrator Bill Nelson.
During a press conference, Nelson, a former astronaut himself, reminded viewers there is nothing unusual about waving off the launch.
Sarafin echoed the same sentiment saying that scrubbing is common, especially when prepping for the first flight.
The mission
Artemis 1 will test the Orion capsule
NASA's Artemis program's aim is to establish a lasting human presence on the Moon with an orbiting space station called Gateway and a base on the surface.
Artemis 1 is the beginning of this mission of historic nature. It will send an uncrewed Orion capsule to lunar orbit.
The purpose of the mission is to test whether the capsule is safe for humans.
Lunar landing
Artemis 3 will land on lunar surface with human beings
After Artemis 1, NASA plans to send Artemis 2 in 2024 with astronauts to orbit around the Moon without landing on the surface.
In 2025 or 2026, we might see Artemis 3 landing on the lunar surface with astronauts for the first time since the last Apollo mission in 1972.
As of now, missions till Artemis 9 are being planned.