Engineers and technicians inside the Vehicle Assembly Building (VAB) at NASA’s Kennedy Space Center in Florida stacked the first segment of the Artemis II SLS (Space Launch System) rocket boosters onto mobile launcher 1.
Comprising 10 segments total – five segments for each booster – the SLS solid rocket boosters arrived via train to NASA Kennedy in September 2023 from Northrop Grumman’s manufacturing facility in Utah. The booster segments underwent processing in the spaceport’s Rotation, Processing and Surge Facility before being transferred to the NASA’s iconic VAB for stacking operations.
Technicians inside the 525-foot-tall facility used an overhead crane to lift the left aft assembly onto the mobile launcher. Up next, workers will install the right aft assembly, placing it carefully onto the 380-foot-tall structure used to process, assemble, and launch the SLS rocket and Orion spacecraft.
The first components of the Artemis II Moon rocket to be stacked, the solid rocket boosters will help support the remaining rocket segments and the Orion spacecraft during final assembly. At launch, the 177-foot-tall twin solid rocket boosters provide more than 75 percent of the total SLS thrust during liftoff from NASA Kennedy’s Launch Pad 39B.
Since the mobile launcher returned in October from Launch Pad 39B to the Vehicle Assembly Building (VAB) at NASA’s Kennedy Space Center in Florida, work has been underway for upcoming stacking operations of NASA’s SLS (Space Launch System) Moon rocket.
To prepare for launch, the mobile launcher is undergoing optical scans, system checkouts, and umbilical refurbishment, including installation of the aft skirt electrical umbilicals.
The booster segments soon will move from the Rotation, Processing and Surge Facility to the VAB via a transporter. The aft assemblies, or bottom portions of the five segment boosters, will be situated in the facility’s transfer aisle then lifted atop the mobile launcher in High Bay 3.
The examinations and preparations of the mobile launcher and rocket elements lay the groundwork for Artemis II crewed test flight around the Moon.
NASA rolled closer to integrating elements of the Artemis II Moon rocket together as teams with the agency’s Exploration Ground Systems Program at Kennedy Space Center in Florida began moving the mobile launcher 1 from Launch Complex 39B along a 4.2 mile stretch back to the Vehicle Assembly Building. First motion of the mobile launcher, atop NASA’s crawler-transporter 2, occurred at 12:09 a.m. EDT Thursday, Oct. 3.
Teams rolled the mobile launcher out to Kennedy’s Pad 39B in August 2023 for upgrades and a series of ground demonstration tests in preparation for NASA’s Artemis II mission. These preparations ranged from a launch day demonstration for the crew, closeout crew, and the pad rescue team, to testing the emergency egress system, water flow system, and the new liquid hydrogen sphere at the launch pad.
On its way to transport the mobile launcher back from the pad, NASA’s crawler-transporter 2 also achieved a milestone nearly 60 years in the making. Already designated by Guinness World Records as the heaviest self-powered vehicle – larger than a baseball infield and weighing approximately 6.65 million pounds – the crawler reached 2,500 miles traveled since its construction in 1965.
The mobile launcher is expected to arrive outside the Vehicle Assembly Building around 10 a.m. Thursday, Oct.3, before the Exploration Ground Systems teams move it into High Bay 3 on Friday, Oct.4.
Follow the livestream of the mobile launcher on the move.
The twin boosters will power the first flight of the agency’s new deep space rocket on its first Artemis Program mission. Artemis I will be an uncrewed flight to test the SLS rocket and Orion spacecraft as an integrated system ahead of crewed flights.
Before the most powerful rocket in existence can lift off for lunar missions, it must first make the 4.2-mile trek from the Vehicle Assembly Building (VAB) to the launch pad at NASA’s Kennedy Space Center in Florida.
For the Artemis I mission, the path from the VAB to Launch Complex 39B must be able to support the behemoth Crawler Transporter-2 — as well as the massive weight of the Space Launch System (SLS) rocket, the Orion capsule, and the mobile launcher. Teams at Kennedy are working to ensure the crawlerway is strong enough to withstand the weight and provide stability for the Artemis I mission and then some.
“Conditioning the crawlerway is important to prevent a phenomenon we call liquefaction, in which the crawler transporter, the mobile launcher, and the load on it causes the crawlerway to vibrate and shake the soil,” said Robert Schroeder, design manager of the crawlerway conditioning project and engineer at Kennedy. “Essentially, the soil itself will behave like a liquid instead of a solid, which could cause the crawler to tip to one side or the other.”
The crawlerway is currently required to support 25.5 million pounds for the Artemis I mission. However, as essential payloads will be added on future missions, the teams at Kennedy decided to test additional weight so they would be “ahead of the ballgame,” Schroeder said.
Work to prepare the crawlerway began Nov. 23. Over the next few months, technicians will lift several concrete blocks, each weighing over 40,000 pounds, onto the mobile launcher platform used for the space shuttle and Crawler Transporter-2. They will then drive the loaded transporter up and down the path between the VAB and launch pad, with each pass increasingly compacting the soil. By the time the project ends, the crawlerway will have supported more than 26 million pounds.
Artemis I will be the first in a series of increasingly complex missions to the Moon. Under the Artemis program, NASA aims to land the first woman and the next man on the Moon in 2024 and establish sustainable lunar exploration by the end of the decade.
Before NASA’s mighty Space Launch System (SLS) rocket can blast off from the agency’s Kennedy Space Center to send the Orion spacecraft into lunar orbit, teams across the country conduct extensive testing on all parts of the system. Guiding that effort at the Florida spaceport are NASA test directors, or NTDs.
NTDs within the Exploration Ground Systems program are in charge of flight and ground hardware testing in Kennedy’s Launch Control Center firing rooms 1 and 2, where activities involved with preparing rockets, spacecraft and payloads for space can be controlled from computer terminals. They are responsible for emergency management actions, helping lead the launch team during all facets of testing, launch and recovery.
NASA’s Artemis missions will land American astronauts on the Moon by 2024, beginning with Artemis I, the uncrewed flight test of SLS and Orion.
“It’s certainly an amazing feeling to be responsible for setting up the building blocks of a new program which will eventually take us to the Moon, Mars and beyond,” said Senior NASA Test Director Danny Zeno.
Zeno is leading the development of test plans and procedures that are essential to flight and ground hardware for the Artemis missions. This includes proving the functionality of flight and ground systems for the assembled launch vehicle configuration, verifying the mobile launcher arms and umbilicals operate as expected at launch, and performing a simulated launch countdown with the integrated vehicle in the Vehicle Assembly Building.
The 14-year NTD veteran relishes his hands-on role in successfully testing and launching SLS — the most powerful rocket NASA has ever built.
“It’s very fulfilling,” Zeno said. “What excites me about the future is that the work I’m doing today is contributing to someday having humans living and working on other planets.”
There are 18 people in the NTD office — all of whom must undergo rigorous certification training in the management and leadership of test operations, systems engineering and emergency response. They are in charge of the people, hardware and schedule during active firing room testing.
“The NTD office is at the center of testing operations, which will ensure that we are ready to fly the Artemis missions,” said Launch Director Charlie Blackwell-Thompson. “As we lay the foundation for exploring our solar system, the NASA test directors are on the front lines of making it happen.”
An NTD works from a console in the firing room during integrated or hazardous testing, guiding the team through any contingency or emergency operations. They lead critical testing on Launch Pad 39B and the mobile launcher, the 370-foot-tall, 11 million-pound steel structure that will launch the SLS rocket and Orion spacecraft on Artemis missions to the Moon and on to Mars. This includes sound suppression, fire suppression and cryogenic fluid flow tests, as well as testing the crew access arm and umbilicals — connections that will provide communications, coolant and fuel up until launch.
While the majority of work for the ground and flight systems is pre-liftoff, the job certainly doesn’t end there.
“It culminates in a two-day launch countdown in which all of the groups, teams and assets are required to function together in an almost flawless performance to get us to launch,” said Senior NASA Test Director Jeff Spaulding.
Spaulding has nearly three decades of experience in the Test, Launch and Recovery Office. For Artemis I, he is leading the launch control team and support teams during the launch countdown for Blackwell-Thompson, who will oversee the countdown and liftoff of SLS.
Just over three miles from the launch pad, on launch day, Spaulding will be in the firing room running the final portion of cryogenic loading through launch. During this time, supercool propellants — called cryogenics — are loaded into the vehicle’s tanks. He will perform the same tasks for the wet dress rehearsal, which is a full practice countdown about two months before launch that includes fueling the tanks and replicating everything done for launch prior to main engine start.
At the end of the mission, part of the team will lead the recovery efforts aboard a Navy vessel after Orion splashdown. The NASA recovery director and supporting NTDs are responsible for planning and carrying out all operations to recover the Orion capsule onto a U.S. Navy ship. This includes working closely with the Department of Defense to ensure that teams coordinate recovery plans, meet requirements, and follow timelines and procedures to bring our heroes and spacecraft home quickly and safely.
“We are supported by numerous teams at Kennedy and elsewhere around the country that are helping us with our historic first flight as we blaze a path toward landing astronauts on the Moon in 2024,” Spaulding said.