NASA has confirmed that it will again attempt to launch the Artemis I moon mission, on Friday, 2 September, five days after it cancelled the first attempt due to engine issues.
Weather reports predict only a 40 percent chance of favourable launch conditions on Saturday. The United States space agency also said that it is working on some outstanding technical issues in the meantime.
The launch was initially scheduled on Monday during a window that opened at 6 pm Indian Standard Time (IST) from the Kennedy Space Center in Florida.
Artemis I, which won't have any humans on board, is intended to be the first in a series of increasingly complex missions with a long term goal of building human presence on the moon.
What Was the Issue?
The Artemis I mission will be propelled by the 322 feet tall Space Launch System (SLS) rocket, which NASA calls the most powerful rocket in the world.
This rocket has four main RS-25 engines which must be thermally conditioned before a super cold propellant begins flowing through them. This is done by increasing the pressure on the liquid hydrogen tank to “bleed” a portion of the liquid hydrogen to the engines.
However, due to issues with the engine bleed, NASA's teams could not get one of the engines to the proper temperature range required, and ran out of time in the two-hour launch window.
During the countdown, launch controllers worked through several other issues, including storms that delayed propellant loading operations, a leak at the quick disconnect system on the 8-inch line used to fill core-stage liquid hydrogen, and an internal hydrogen leak.
Another Window on Friday
NASA hosted a media teleconference on Tuesday, 30 August, to provide an update on the launch. It now hopes to launch the SLS on Saturday afternoon, during a two-hour launch window which opens at 10:18 pm IST.
In the meantime, it plans to keep the rocket and its Orion astronaut capsule on its launch pad in the Kennedy Space Center in Cape Canaveral, Florida, to avoid having to take it back into the assembly building for more tests and repairs, since this would eat up more time.
"We don't launch until it's right," said former astronaut and NASA Administrator Bill Nelson, who insisted that being cautious was the right thing to do.
"I think it's just illustrative that this is a very complicated machine, a very complicated system. And all those things have to work. You don't want to light the candle until it's ready to go," he added.
The primary goals of Artemis I are to "demonstrate Orion’s systems in a spaceflight environment and ensure a safe re-entry, descent, splashdown, and recovery prior to the first flight with crew on Artemis II."
Overall, NASA has outlined three major reasons for why we're headed to the Moon once more:
For scientific discovery
To establish an economy based around the moon and its resources
To eventually go to Mars using the lessons from Artemis