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.

Orion Makes a Big Splash for Artemis II

The Orion spacecraft structural test article was successfully drop tested April 6 in the hyrdro impact basin at NASA’s Langley Research Center’s Landing and Impact Research Facility in Hampton, Virginia. Data collected from 500 sensors during the drop will help researchers finalize computer models of extreme landing conditions prior to Artemis II. This was the second of four drops in this series of tests.

 

Under Pressure! New Rainbird System Will Protect Artemis II

Water spraying out of a nozzle for rainbird testing for the Artemis II mission.
Water flows through a small-scale, 3D-printed nozzle during prototype testing of a new rainbird system on March 24, 2021, at NASA’s Kennedy Space Center in Florida. Photo credit: NASA/Ben Smegelsky

As NASA prepares for the uncrewed Artemis I test flight, teams at the agency’s Kennedy Space Center are also hard at work getting ready for the Artemis II mission that will send astronauts on a trip around the Moon ahead of a crewed lunar landing.

Water flows through large nozzles during rainbird testing for the Artemis II mission.
Teams with NASA’s Exploration Ground Systems and supporting contractors conduct prototype testing of a new rainbird system at the agency’s Kennedy Space Center in Florida on March 24, 2021, that can be used for the crewed Artemis II mission to the Moon. Photo credit: NASA/Ben Smegelsky

This includes assessing a new prototype “rainbird” system designed to protect the mobile launcher – as well as NASA’s Space Launch System (SLS) – when the engines roar to life. The March 24 tests included running various water pressures through small-scale, 3D-printed nozzles to capture data that can be used to develop full-scale hardware.

The rainbirds will release enough water to fill 40 swimming pools in 40 seconds. This massive volume will help absorb the heat and energy when SLS, the most powerful rocket the agency has ever built, lifts off with the Orion spacecraft from Kennedy’s Launch Pad 39B.

While upgraded rainbirds – large-scale water nozzles – have already been tested and installed on the mobile launcher for the Artemis I launch, Exploration Ground Systems (EGS) found room for improvement. This led teams from EGS and supporting contractors to start testing another prototype system to distribute water more evenly to maximize performance ahead of the Artemis II launch.

Water flows through a nozzle during rainbird testing for the Artemis II mission.
Alongside the iconic Vehicle Assembly Building at NASA’s Kennedy Space Center in Florida, teams with the agency’s Exploration Ground Systems and supporting contractors conduct prototype testing of a new rainbird system on March 24, 2021. Photo credit: NASA/Ben Smegelsky

“By running our prototype through a range of pressures, we can simulate what each of the rainbirds will see on the mobile launcher on launch day and have a better understanding of how they will perform when we scale them back up to full size,” said Dave Valletta, a design engineer at Kennedy working on the ignition overpressure protection and sound suppression (IOPSS) system.

A critical piece of the IOPSS system, the rainbird got its name decades ago when space shuttle developers noted that it looked like a garden sprayer.

“When we saw the pattern of the water discharge during the first test flow in the shuttle program, it reminded us of your common lawn sprinkler, only it did not rotate and was 100 times the size,” said Jerry Smith, a design engineer for mechanical-fluid systems at Kennedy.

Once prototype testing is complete, allowing better prediction of future spray patterns, the team will move forward with designing a preferred concept. That concept will be built and installed on the mobile launcher to undergo verification and validation testing, where the newly installed nozzles will be fully integrated with the launch pad to ensure they work as expected.

“The confidence check gained from these tests will lead us to developing full-scale nozzles for the mobile launcher,” said Gerald Patterson, IOPSS and fire suppression system operations engineer and test lead. “Once installed, they’ll provide more efficient water distribution across the deck and, ultimately, better protection to ground systems, the SLS rocket, and its crew for Artemis II and beyond.”

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: Full Duration Hot Fire Successfully Completed on Mar. 18

Teams from NASA’s Space Launch System (SLS) Program conducted a successful full-duration 8 minute (499.6 seconds) hot fire of the Artemis I core stage on Thursday, Mar. 18 at NASA’s Stennis Space Center near Bay St. Louis, Mississippi on the historic B-2 Test Stand.

The hot fire got underway at around 4:40 p.m. EDT with all four RS-25 engines ignited successfully and produced 1.6 million pounds of thrust, as they will to launch the Artemis I mission to the Moon. During the test the engines consumed more than 700,000 gallons of liquid oxygen and liquid hydrogen propellant. The test was conducted with the core stage that will launch that first Artemis mission. Engineers collect data on how the stage behaved during critical operations, such as throttling the engines up and down and moving the engines dynamically in a variety of patterns. In coming days, engineers will scrutinize the data and determine if the stage is ready to be delivered to NASA’s Kennedy Space Center in Florida where it will be integrated with the twin solid rocket boosters already stacked in the Vehicle Assembly Building.

The core stage Green Run was a series of eight tests - all checked.
The core stage Green Run was a series of eight tests to checkout and validate operations with the largest rocket stage NASA has ever built. The flight hardware for the Artemis I mission was used for the test.

To learn more, tune in to NASA TV for a post-test briefing in about 2 hours.

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.

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.