NASA Team Preparing Hardware for Future Moon Rockets

Technicians and engineers continue to make progress manufacturing core stages that will help power NASA’s Space Launch System (SLS) rocket for its second and third flights. NASA and Boeing, the lead contractor for the core stage, are in the process of conducting one of the biggest Artemis II milestones: assembling the top half of the core stage.

The 212-foot tall core stage for the SLS rocket is the largest rocket stage NASA has ever produced. The five individual elements that make up the core stage – the forward skirt, liquid oxygen tank, intertank, liquid hydrogen tank, and the engine section – are manufactured and assembled at NASA’s Michoud Assembly Facility in New Orleans. Together, the elements will supply propellant, vehicle control, and power to the four RS-25 engines at the bottom of the stage to produce more than 2 million pounds of thrust to send missions to the Moon.

The team manufactures every SLS core stage in Michoud’s 43-acre building which provides more than enough space for crews to work in tandem to build the core stages for Artemis II and Artemis III, the second and third flights of the SLS rocket and the first crewed missions of NASA’s Artemis program.

It takes teamwork to build a super heavy-lift rocket. Look behind the scenes at the work being done at NASA’s rocket factory:

The Artemis II Intertank is lifted into the Cell D of the VAB at NASA Michoud Assembly Facility on Friday, March 19, 2021.

Coming together to build the upper part of the rocket

After all the core stage’s large five structures are built and outfitted, these structures are connected during three major joining operations. For first one, the forward or upper parts of the core stage are joined together for the first time. First, teams move the intertank into an assembly area and connect it to the liquid oxygen tank, and then they add the forward skirt to form the entire upper part of the SLS core stage.

Crews with NASA and Boeing, the core stage prime contractor, recently moved the Artemis II intertank, above, to the assembly area where the three components will be stacked.

This image shows the forward skirt that will be used on the core stage of NASA’s Space Launch System rocket for Artemis II, the first crewed mission of NASA’s Artemis program, at NASA’s Michoud Assembly Facility. The SLS core stage is made up of five unique elements: the forward skirt, liquid oxygen tank, intertank, liquid hydrogen tank, and the engine section. The forward skirt houses flight computers, cameras, and avionics systems. The hardware is located at the top of the 212-foot-tall core stage and connects the upper part of the rocket to the core stage. Soon, technicians will ready the forward skirt for the first of three core stage assembly mates called the forward join. The forward join consists of three main parts -- the forward skirt, liquid oxygen tank, and intertank – to create the top, or forward part, of the core stage. Together with its four RS-25 engines, the rocket’s massive 212-foot-tall core stage — the largest stage NASA has ever built — and its twin solid rocket boosters will produce 8.8 million pounds of thrust to send NASA’s Orion spacecraft, astronauts and supplies beyond Earth’s orbit to the Moon and, ultimately, Mars. Offering more payload mass, volume capability and energy to speed missions through space, the SLS rocket, along with NASA’s Gateway in lunar orbit, the human landing system, and Orion spacecraft, is part of NASA’s backbone for deep space exploration and the Artemis lunar program. No other rocket is capable of carrying astronauts in Orion around the Moon in a single mission. Image credit: NASA/Michael DeMocker

The Artemis II forward skirt, pictured above, has been outfitted and is ready for integration with the other large core stage structures. The forward skirt houses flight computers, cameras, and avionics systems. It is located at the very top of the core stage and connects to the upper part of the rocket.

This image highlights the liquid oxygen tank, which will be used on the core stage of NASA’ Space Launch System rocket for Artemis II, the first crewed mission of NASA’s Artemis program, at NASA’s Michoud Assembly Facility. The SLS core stage is made up of five unique elements: the forward skirt, liquid oxygen tank, intertank, liquid hydrogen tank, and the engine section. The forward skirt houses flight computers, cameras, and avionics systems. The liquid oxygen tank holds 196,000 gallons of liquid oxygen cooled to minus 297 degrees Fahrenheit. The LOX hardware sits between the core stage’s forward skirt and the intertank. Along with the liquid hydrogen tank, it will provide fuel to the four RS-25 engines at the bottom of the core stage to produce more than two million pounds of thrust to launch NASA’s Artemis missions to the Moon. Together with its four RS-25 engines, the rocket’s massive 212-foot-tall core stage — the largest stage NASA has ever built — and its twin solid rocket boosters will produce 8.8 million pounds of thrust to send NASA’s Orion spacecraft, astronauts and supplies beyond Earth’s orbit to the Moon and, ultimately, Mars. Offering more payload mass, volume capability and energy to speed missions through space, the SLS rocket, along with NASA’s Gateway in lunar orbit, the Human Landing System, and Orion spacecraft, is part of NASA’s backbone for deep space exploration and the Artemis lunar program. No other rocket can send astronauts in Orion around the Moon in a single mission. Image credit: NASA/Michael DeMocker

Moving through the manufacturing process

The core stage has two huge cryogenic liquid propellant tanks that collectively hold more than 733,000 gallons of liquid propellant to help launch the Space Launch System rocket to the Moon. Moving the immense hardware, especially the two propellant tanks, around the factory is a delicate process.

Teams carefully orchestrate every step of every lift and transport inside and outside the rocket factory. To safely and securely move hardware, they use special transporters and cranes that are designed to contain, hold, and handle the weight of each element. Above, teams move the more than 130-foot-tall liquid hydrogen tank to the same area as the liquid oxygen tank. Both propellant tanks will be used for Artemis II.

The aisles at Michoud are extra-wide to ensure large hardware can be transported throughout the factory. For the next phase of manufacturing, crews recently moved the boat-tail, a fairing-like cover that attaches to the engine section on the bottom of the core stage. The boat-tail is shown in the image foreground, and the engine section for Artemis II can be seen in the background covered with scaffolding. The four RS-25 engines for the SLS rocket will be mounted inside the engine section, and the boat-tail helps to protect and cover most of the four RS-25 engines’ critical systems.

Fusion Weld on H3 R2

It’s all in the details

As crews prepare the core stage elements that will be used for Artemis II for assembly and integration, the hardware for Artemis III is being welded in other areas of the factory. Engineers and technicians use friction-stir welding methods to connect the panels that make up each piece of hardware together and build larger structures. Fusion welding is traditional welding, and it uses heat to plug holes left by machines welding the larger pieces as well as for any necessary weld repairs.

Welding processes help to create the shells, or outside, of the core stage structures. Above, the engine section for Artemis III comes together in the Vertical Weld Center at Michoud. They are made by connecting panels such as the one in the front of this image. The engine section has been completed and moved to another part of the factory. One of the biggest tasks ahead, is outfitting it with a network of internal components and systems that connect to the RS-25 engines.

In May, the core stage team will begin work on the Artemis IV core stage, so three stages will be under construction at the same time. Because of the factory’s size, state-of-the-art equipment, and manufacturing processes, skilled workers can produce multiple rocket stages to power NASA’s next-generation Moon missions through the Artemis program.

NASA is working to land the first woman and the first person of color on the Moon. SLS and Orion, along with the human landing system and the Gateway in orbit around the Moon, are NASA’s backbone for deep space exploration. SLS is the only rocket that can send Orion, astronauts, and supplies to the Moon in a single mission.

NASA Removes Rocket Core Stage for Artemis Moon Mission from Stennis Test Stand

Crews at NASA’s Stennis Space Center near Bay St. Louis, Mississippi, worked April 19-20 to remove the first flight core stage of the agency’s Space Launch System rocket from the B-2 Test Stand in preparation for its transport to Kennedy Space Center in Florida. Operations required crews to lift the core stage from its vertical placement in the stand and lower it to a horizontal position on the B-2 Test Stand tarmac. The stage now will be loaded on NASA’s Pegasus barge for transport to Kennedy, where it will be prepared for launch of the Artemis I mission. Removal of the largest rocket stage ever built by NASA followed completion of a series of eight Green Run tests over the past year. During the Green Run series, teams performed a comprehensive test of the stand’s sophisticated and integrated systems. The series culminated in a hot fire of the stage’s four RS-25 engines on the B-2 stand March 18. During the hot fire, the four engines generated a combined 1.6 million pounds of thrust, just as during an actual launch. The test was the most powerful performed at Stennis in more than 40 years. NASA is building SLS, the world’s most powerful rocket, to return humans to deep space missions. As part of the backbone of NASA’s Artemis program, SLS will return humans, including the first woman and person of color, to the surface of the Moon to establish a sustainable presence and prepare for eventual missions to Mars.

Removal the first flight core stage of the agency’s Space Launch System rocket from the B-2 Test Stand
Credit: NASA
Removal the first flight core stage of the agency’s Space Launch System rocket from the B-2 Test Stand
Credit: NASA
Removal the first flight core stage of the agency’s Space Launch System rocket from the B-2 Test Stand
Credit: NASA
Removal the first flight core stage of the agency’s Space Launch System rocket from the B-2 Test Stand
Credit: NASA

Artemis I Core Stage Being Readied for Shipment to Kennedy

The Space Launch System (SLS) core stage Green Run team has reviewed extensive data and completed inspections that show the rocket’s core stage and engines are in excellent condition after the full-duration Green Run hot fire test on Mar. 18.

This test at NASA’s Stennis Space Center near Bay St. Louis, Mississippi allowed the team to obtain data to meet all the hot fire test objectives. This second hot fire test with the core stage flight hardware that will launch the Artemis I mission to the Moon was described as “flawless” by the test team that included NASA and prime contractors Boeing and Aerojet Rocketdyne. The team encountered no issues during the test that started with powering up the core stage on Mar. 16.

While analyzing data, the team refurbished the core stage in preparations for shipping it this month to NASA’s Kennedy Space Center in Florida for the Artemis I launch. Refurbishment activities included drying the RS-25 engines and making expected repairs to the engines and the thermal protection system on the core stage.

This week, the team powered up the core stage and loaded the flight software that will be used for the Artemis I mission. Now, they are disconnecting systems that connect the stage to the B-2 Test Stand. Next, the stage will undergo final shipping preparations before it is lifted out of the stand and placed on the Pegasus barge.

Check back at this blog for updates as the Artemis I core stage prepares for its voyage to Kennedy.

Fueling Underway For Artemis I Launch

A view of the Interim Cryogenic Propulsion System in the Multi-Payload Processing Facility at NASA's Kennedy Space Center in Florida.
A view of the Interim Cryogenic Propulsion System in the Multi-Payload Processing Facility at NASA’s Kennedy Space Center in Florida on Feb. 18, 2021. Photo credit: NASA/Glenn Benson

Teams with NASA’s Kennedy Space Center Exploration Ground Systems and primary contractor, Jacobs, are fueling the Orion service module ahead of the Artemis I mission. The spacecraft currently resides in Kennedy’s Multi-Payload Processing Facility alongside the Interim Cryogenic Propulsion System (ICPS), the rocket’s upper stage that will send Orion to the Moon. After servicing, these elements will be integrated with the flight components of the Space Launch System, which are being assembled in the Vehicle Assembly Building.

Technicians began loading Orion’s service module with oxidizer, which will power the Orbital Maneuvering System main engine and auxiliary thrusters on the European-built service module ahead of propellant loading. These auxiliary thrusters stabilize and control the rotation of the spacecraft after it separates from the ICPS. Once the service module is loaded, teams will fuel the crew module to support thermal control of the internal avionics and the reaction control system. These 12 thrusters steady the crew module and control its rotation after separation from the service module.

Once Orion servicing is complete, teams will fill the ICPS. This liquid oxygen/liquid hydrogen-based system will push the spacecraft beyond the Moon for the test flight under the agency’s Artemis program. In several weeks, when fueling is complete, Orion will move to the center’s Launch Abort System Facility to integrate its launch abort system, and the ICPS will move to the Vehicle Assembly Building to be stacked atop the mobile launcher.

NASA Begins Major Assembly of Rocket Stage for First Crewed Artemis Mission

The NASA team is moving parts of the Space Launch System rocket to begin assembly of the forward, or upper part, of the rocket’s core stage for the Artemis II Moon mission. On March 19, the intertank was moved to the vertical assembly area at NASA’s Michoud Assembly Facility in New Orleans where the core stage is manufactured. The intertank flight hardware is part of the upper portion of the core stage that will help power Artemis II, the second flight of the deep space rocket and the first crewed lunar mission of NASA’s Artemis program.

Space Launch System rocket’s intertank
The Space Launch System rocket’s intertank is the first piece of the upper part of the core stage to be moved for stacking in the vehicle assembly area at NASA’s Michoud Assembly Facility in New Orleans.

To form the massive, 212-foot-tall core stage for the agency’s Moon rocket, five major structures are joined together: the forward skirt, liquid oxygen tank, intertank, liquid hydrogen tank, and engine section. NASA and Boeing, the core stage prime contractor, are preparing to connect three structures together to create the forward assembly of the core stage. The process of stacking and assembling the forward skirt, liquid oxygen tank, and intertank is called the forward join, and it is the first major vertical integration of hardware for the Artemis II core stage. The intertank is first installed in a vertical stacking cell at Michoud. Later, teams will move the liquid oxygen tank and forward skirt to the same area to stack the three structures together.

Ifographic on forward joinThe intertank contains avionics that are the “brains” of the rocket. It also serves as one of the main attach points for the twin solid rocket boosters that work with the core stage to send SLS to space. The core stage will supply propellant and power to the four RS-25 engines at the bottom of the stage to produce the remaining 2 million pounds of thrust needed to send the Artemis II mission to orbit.

NASA is working to land the first woman and the next man on the Moon. SLS and Orion, along with ground systems at Kennedy, the human landing system and the Gateway in orbit around the Moon, are NASA’s backbone for deep space exploration. SLS is the only rocket that can send Orion, astronauts, and supplies to the Moon in a single mission. (NASA image)

Green Run Update: Post-Test Press Briefing at 7 p.m. ET.

Teams from NASA’s Space Launch System (SLS) Program conducted a successful full-duration hot fire test for more than 8 minutes. See press release HERE.

To learn more, tune in to NASA TV for a post-test briefing at 7 p.m. EDT at NASA Live.

Learn more about Green Run, and check back at this blog for updates on the SLS core stage hot fire test. Watch a replay of the test on NASA Television or NASA’s YouTube channel. For all the photos and videos related to the test, visit, the Green Run Album on NASA Images.org.

Video of today’s test can be downloaded there as well.

Green Run Update: Engines Igniting as Hot Fire Gets Underway

The hot fire is underway for the Space Launch System (SLS) rocket core stage at NASA’s Stennis Space Center near Bay St. Louis, Mississippi.

Engine ignition began at approximately six tenths of a second before T-0, beginning with Engine 1, then Engines 3, 4, and 2 ignited in sequence a few hundredths of a second apart. The test is expected to last about 8 minutes and will include three different power levels for the engines, as well as  engine gimballing, or pivoting, movements to simulate flight steering commands. Depending on the rate propellant is burned, the time is estimated to range from 485 to 493 seconds to simulate launch.

core stage RS-25 engines
All four of the Artemis I core stage RS-25 missions served on numerous space shuttle missions. Now they will launch the Artemis I mission to the Moon. Aerojet Rocketdyne is the prime contractor for the engines.

Learn more about Green Run, and check back at this blog for updates on the SLS core stage hot fire test.

Green Run Update: Terminal Countdown Sequence Started

The test conductor polled the team and has approved the decision to proceed with the terminal countdown that includes the final 10 minutes before the hot fire. During the terminal countdown, the team is executing the autonomous launch sequence that simulates the countdown for the Artemis I launch. The test transitions from ground control to on-board software control of the core stage and so the test is fully automated starting at T-30 seconds.

Key milestones during the final count include starting the core stage auxiliary power units (CAPUs) for each engine to provide power for the thrust vector control systems that gimbal, or move, the engines during the test, purging the engines with nitrogen gas to ensure they are completely clean before flowing propellant, moving the engines into position for engine start, and switching the core stage from external test stand power to internal battery power. The engines begin to power up 6 seconds before T-0.

Propellant barges docked near the B-2 Test Stand

Below are the key milestones in the terminal countdown:

  • T-4 minutes: Core Stage Auxiliary Power Unit CAPU Start
  • T-3 minutes: Engine Purge Sequence Start
  • T-2 minutes, 30 seconds: Pre-Ignition Gimbal Sequence Started
  • T-1 minute, 30 seconds: Core Stage to Internal Power
  • T-33 seconds: Automated Launch Sequence (ALS) Start
  • T-6 seconds: Engine Start Commands

The B-2 test stand flame deflector cooling water also will begin flowing to protect the deflector from superheated engine exhaust about a minute and a half before firing up the engines, and test stand acoustic suppression water flow will begin about 65 seconds before hot fire.

Hear the test conductor in the final minutes before the countdown during live coverage underway on NASA Television and the agency’s website.

Learn more about Green Run, and check back at this blog for updates on the SLS core stage hot fire test.

Green Run Update: NASA TV Coverage Underway for Hot Fire Test

Countdown is continuing for the hot fire test of the core stage for NASA’s Space Launch System (SLS) rocket. The test is expected to start soon and last about 8 minutes to simulate launch and ascent of the SLS to orbit.

NASA Television coverage has begun. Watch live: http://www.nasa.gov/live

Teams powered up the core stage’s avionics systems Tuesday, Mar. 16, and began the countdown for the hot fire test earlier today. The team is continuing to closely monitor core stage and facility performance before proceeding into the final phase of the test: the terminal countdown leading to the hot fire.

During this test, the team has repeated many of the major milestones marked during the wet dress rehearsal and the first hot fire test, including chilling the main propulsion system and completely filling both propellant tanks. Coming up at 10 minutes before the test, the test conductor will poll the team who will give the final “go/no go” to proceed with the hot fire test.

Learn more about Green Run, and check back at this blog for updates on the SLS core stage hot fire test.

 

Green Run Update: Tanking Complete for Rocket Hot Fire Test

Engineers have completed tanking for the hot fire test of NASA’s Space Launch System (SLS) rocket core stage at the agency’s Stennis Space Center, and the countdown is proceeding normally.

The liquid hydrogen tank holds 537,000 gallons of liquid hydrogen, cooled to minus 423 degrees Fahrenheit. The liquid oxygen tank holds 196,000 gallons of liquid oxygen, cooled to minus 297 degrees Fahrenheit. After tanking is complete, the team will continue chilling down the liquid oxygen propellant to condition it before the hot fire. While they are conditioning the liquid oxygen, they replenish the liquid hydrogen as it boils off due to temperature fluctuations as the propellant is loaded. The tanks can be loaded up to 22 times for testing and launches.

core stage liquid hydrogen tank
This image shows the core stage liquid hydrogen tank at NASA’s Michoud Assembly Facility in New Orleans where it and the rest of the core stage where built and assembled. The flight core stage for the Artemis I mission is being tested today. Boeing, the prime contractor for the core stage, has already manufactured liquid hydrogen tanks for the Artemis II and Artemis III lunar missions.

This part of the test timeline is also important as it pertains to simulating launch. During a launch, many activities will be happening on the pad at this time, such as loading the crew. The hot fire test provides an opportunity to demonstrate that the core stage can remain in a stable configuration and be replenished as needed before engine firing to launch the rocket.

Learn more about Green Run, and check back at this blog for updates on the SLS core stage hot fire test.