After a successful test, NASA says the weather forecast will determine whether it launches its Artemis 1 round-the-moon mission a third time the following week.
It's not just routine weather; a tropical depression in the Caribbean Sea might intensify into a hurricane and make landfall along the Florida coast.
Currently, NASA is continuing to make final preparations for the launch scheduled for next Tuesday from Florida's Kennedy Space Center.
Since the cryo test was successful and we don't currently have a prediction that fails our weather requirement, we should really be calling this Plan A.
The National Weather Service's most recent prediction computer models for the storm system being called Tropical Depression 9 may require a change in that approach.
On Wednesday, the newly installed fixes and new procedures were tested. John Blevins, NASA's SLS programme chief engineer.