NASA’s massive Space Launch System (SLS) rocket, Orion spacecraft, and Exploration Ground Systems are undergoing a critical final pre-launch test this weekend. The test, known as a wet dress rehearsal, will run the Artemis I launch team through all pre-launch activities, including loading propellant into the rocket’s tanks and conducting a full launch countdown.
The SLS rocket is the most powerful rocket in the world, and it’s assembled right here in New Orleans at NASA’s Michoud Assembly Facility. The rocket stands at 322 ft tall when fully assembled with the Orion Spacecraft attached, and will weigh 5.75 million pounds at liftoff. Over the course of its moon mission, Artemis I will travel 1.3 million miles over four to six weeks. It’s designed to be the first in a series of missions intended to build a long-term human presence on the Moon.
During the two-day wet dress rehearsal, which began early Saturday morning, teams will load more than 700,000 gallons of supercooled propellants into the rocket. Launch teams will practice every phase of the pre-launch countdown, including regular weather briefings, pre-planned holds, conditioning and replenishing propellant as needed, and various validation checks. As the countdown reaches a point jut before the rocket’s RS-25 engines would ignite on launch day, the countdown will be recycled to the T-10 minute point, hold briefly, then restart. The countdown will then be deliberately halted at around T-10 seconds in order to simulate a “scrubbed” launch. The propellants will be drained from the rocket.
Following the wet dress rehearsal, the integrated SLS rocket and Orion spacecraft will be moved back into NASA’s Vehicle Assembly Building at Kennedy Space Center, where technicians will run final checks on the system, remove sensors placed specifically for the wet dress rehearsal charge Orion’s batteries, load last-minute cargo onboard, and perform other tasks needed to prepare the spacecraft for launch. Orion and the SLS will be moved back to the launch pad about a week before it’s target launch date, which will be determined after NASA reviews data from the wet dress rehearsal.
While Artemis I is an uncrewed mission, Artemis II and III – which are currently being assembled here in New Orleans – will carry flight crews, with the Artemis III crew landing on the moon.
