Artemis I Still on Track for Tomorrow, September 3

Launch of NASA’s Artemis I uncrewed test flight is still set for tomorrow afternoon, September 3, at 2:17 pm ET. During an update briefing this morning, Launch Weather Officer Melody Lovin again said she does not expect weather to be a showstopper, though the chances are better towards the end of the two-hour launch window. Weather is only one factor that could scrub the launch, but hopes are high tomorrow will be the day.

Problems that affected the first launch attempt on Monday have been resolved or deemed satisfactory for this test flight.

Jeremy Parsons, Deputy Manager, Exploration Ground Systems, confirmed at this morning’s briefing that if the launch does not go tomorrow, they can try again on Monday, but after that they will have to return the rocket to the Vehicle Assembly Building to test the battery for the Flight Termination System (FTS).

The FTS would be used to destroy the rocket if it veered off course. The battery must be tested or replaced 20 days after it’s installed although NASA and the U.S. Space Force agreed to extend that limit to 25 days this time to accommodate a possible Monday launch.

The FTS is inside the orange core stage, in the intertank area between the Liquid Oxygen (LOX) and Liquid Hydrogen (LH2) tanks. It is not accessible when the rocket is on the launch pad. It has to return to the VAB where work platforms allow access to various levels of the 322-foot tall vehicle.

NASA can only launch Artemis I on certain days that comply with various constraints.  For example, the Earth and Moon must be in the correct alignment with each other and the Sun to ensure Orion’s solar panels are not in eclipse for more than 90 minutes and Orion has to launch and splashdown in daylight.

If launch is tomorrow, it will splashdown in the Pacific Ocean near San Diego on October 11 at 2:10 pm EDT (11:10 am Pacific Time) after an approximately 37-day mission.

If the launch scrubs after the propellant tanks are loaded, they will have to wait until Monday at 5:12 pm ET to try again. A 48-hour turnaround is needed to replenish the propellants. Technically they could wait until Tuesday, but that day’s launch window is quite short so NASA is not planning to use it and if they tank the vehicle on Monday there would not be enough turnaround time in any case.

After Tuesday, they have to wait until September 19 when the Earth and Moon line up again. Whether NASA would try at that point depends on a variety of factors including the need to roll the vehicle back to the VAB for the FTS battery test.