Since 2004, NASA has been working on the launch system that will send astronauts to the Moon for the first time since the Apollo Era. These efforts bore fruit in 2011 with the proposed Space Launch System (SLS), the heaviest and most powerful rocket since the Saturn V. Paired with the Orion spacecraft, this vehicle will be the workhorse of a new space architecture that would establish a program of sustained lunar exploration and even crewed missions to Mars.

Due to repeated delays, cost overruns, and the expedited timeframe for Project Artemis, there have been serious doubts that the SLS will be ready in time. Luckily, ground crews and engineers at NASA’s Launch Control Center (LCC) – part of the Kennedy Space Center in Florida – recently finished stacking the Artemis I mission. The vehicle is now in the final phase of preparations for this uncrewed circumlunar flight in February 2022.

The fully-stacked Artemis I rocket includes the SLS Core Stage, the expendable solid rocket boosters, the Orion Multi-Purpose Crew Vehicle (MPCV), and the European Service Module (ESM) – the European Space Agency’s (ESA) contribution to the Artemis Program. Now that these systems are all integrated, they will undergo a series of test campaigns that will evaluate them as a fully integrated system for the first time.

Space Launch System Program (SLS) inside the Vehicle Assembly Building at NASA’s Kennedy Space Center in Florida. Credit: NASA/Frank Michaux

Each of these tests will build upon the last, culminating in a simulation on the launch pad that will serve as a “dress rehearsal” for launch. As Mike Bolger, the Exploration Ground Systems program manager at the LCC, said in a recent NASA press release:

“It’s hard to put into words what this milestone means, not only to us here at Exploration Ground Systems, but to all the incredibly talented people who have worked so hard to help us get to this point. Our team has demonstrated tremendous dedication preparing for the launch of Artemis I. While there is still work to be done to get to launch, with continued integrated tests and Wet Dress Rehearsal, seeing the fully stacked SLS is certainly a reward for all of us.” 

Altogether, four testing campaigns will take place before the “Wet Dress” Rehearsal, where the rocket is fully loaded with cryogenic propellant, and a full pre-launch sequence is conducted. These tests include:

Interface Verification: This campaign will take place in the firing room at the LCC, where the crews will verify the core stage engines, booster thrust control, and the Interim Cryogenic Propulsion Stage (ICPS). The ground crews will also check the functionality and interoperability of the interfaces between the core stage, boosters, and ground systems. A final integrated test of all the wire harnesses throughout the rocket and spacecraft will verify their ability to talk to each other and ground systems.

The core stage for the first flight of NASA’s Space Launch System rocket is seen in the B-2 Test Stand during a second hot fire test, Thursday, March 18th, 2021, at NASA’s Stennis Space Center. Credit: NASA/Robert Markowitz

Program Specific Engineering:
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