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From AIAA “Daily Launch” for 3-4-2026, following a link to Spacnews.com, a Jeff Foust article dated 4 March:
WASHINGTON — Workers have completed repairs to the helium pressurization system in the upper stage of the Space Launch System, keeping a potential April launch of the Artemis 2 mission on track.
In a March 3 statement, NASA said engineers traced a blockage in helium flow in the Interim Cryogenic Propulsion Stage, or ICPS, to a seal in a quick-disconnect line feeding helium from ground equipment into the stage. The seal had become dislodged, blocking helium flow.
Technicians removed the quick-disconnect fitting, reassembled it with the seal properly positioned and reinstalled it. Tests confirmed that helium was flowing into the stage after the repairs.
The quick-disconnect line was one of the leading suspected causes of the blockage, along with a check valve inside the stage. NASA said Feb. 21 that neither issue could be addressed at the launch pad, requiring the agency to roll the vehicle back to the Vehicle Assembly Building for repairs.
While addressing the helium issue, workers also performed maintenance on other parts of the SLS. That included replacing batteries in the core stage, ICPS and boosters, as well as replacing batteries in the rocket’s flight termination system ahead of end-to-end testing required by the Eastern Range.
NASA also said it is replacing a seal in a line that feeds liquid oxygen into the core stage. That seal is separate from those in liquid hydrogen lines that caused leaks during a wet dress rehearsal in early February and were replaced at the pad. NASA did not disclose why it is replacing the liquid oxygen seal, as there were no reports of leaks during the two fueling tests conducted last month.
NASA said the repairs and maintenance keep the vehicle on schedule to roll back out to the pad later this month for a launch attempt in early April. Two-hour launch windows are available on the evenings of April 1, 3, 4, 5 and 6 during the next launch period. The following opportunity opens April 30.
The agency did not disclose when it plans to roll the SLS and Orion spacecraft back to the pad. At a Feb. 27 briefing, Lori Glaze, acting associate administrator for the Exploration Systems Development Mission Directorate, said teams would need “at least a week and a half or so” at the pad after rollout to complete preparations for a launch attempt.
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My take:
The Helium valve seal displacement problem sounds similar to, but not quite the same, as the bad helium valves in Starliner. This was the interim upper stage of the SLS in which this occurred, which is old Delta-4 hardware acquired when Boeing absorbed McDonnell-Douglas. The oxygen seal wasn’t leaking, but got replaced in the first stage core anyway, for unspoken reasons. The first stage core is a Boeing in-house design. Most of the replacements were actually various batteries that were too long past being fully charged.
I've also seen some statements elsewhere from Isaacman, somewhere, about "standardizing" the SLS rocket configuration. There was no clue what that meant, but I suspect it might mean there will only ever be an SLS block 1, with the interim upper stage.
GW
Last edited by GW Johnson (2026-03-04 16:01:08)
GW Johnson
McGregor, Texas
"There is nothing as expensive as a dead crew, especially one dead from a bad management decision"
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It sure is walking and quacking like.... Duck
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Opinion: Isaacman makes his mark by revamping the Artemis return to the moon
It appears Halo or gateway is next since the larger sls is not happening
The strategy involves flying an Earth orbit mission in 2027, in which the Orion spacecraft would rendezvous and dock with one or both of the planned Human Landing Systems, the SpaceX Starship and the Blue Origin Blue Moon. The new mission would be designated Artemis III.
The first lunar landing attempt, now Artemis IV, would take place in early 2028. A possible second lunar landing is envisioned for later that year and would be designated as Artemis V.
Isaacman proposes to adhere to this new, ambitious launch schedule by launching the Space Launch System once every 10 months instead of once every two to three years. He means to accomplish this by “standardizing” the Space Launch System in several ways.
First, he aims to cancel the Exploration Upper Stage, the Mobile Launcher 2 and the 1B configuration, saving billions of dollars. He also plans to fly the Artemis II circumlunar mission and the Artemis III Earth orbit mission with the current upper stage, and to fly the Artemis IV and Artemis V lunar landing missions with a “standardized” new upper stage, possibly a Centaur V.
Left unstated was what would happen to the lunar orbital Gateway Space Station, where crews would transfer from the Orion space capsule to a Human Landing System before proceeding to the lunar surface.
Also missing from Isaacman’s announcement is what will happen to the Space Launch System after Artemis V. The huge, expensive rocket has been authorized through that mission. Will commercial, cheaper means of traveling from the Earth to the moon and back be available by then? The answer is unknown at the present time.
Isaacman received fire from one high-profile critic. Lori Garver, who was NASA deputy administrator during the Obama presidency when the Space Launch System was first authorized, did not mince words in a post on X: “The focus on Artemis spin over substance has been troubling since its inception,” she wrote. “However, expressing confidence that we can add a flight in between and make two lunar landings in 2028 is more magical thinking. We didn’t “wait” 3.5 yrs between launches because we wanted to, that is what it took.”
saacman replied with measured calmness and directness, saying that “accepting a 3.5-year launch cadence, the lowest by far of any NASA-designed program in history, because ‘that is what it took’ is exactly what needs to be fixed.”
“In fact, I am surprised you would describe launching Moon rockets inside a year as ‘magical thinking.’ I would say launching Apollo 8 just weeks after Apollo 7 was magical,” he added.
Isaacman, an engineer who founded two billion-dollar companies, one at the tender age of 16, and flew into space twice on his own dime, has certainly done impossible things before. He is confident that he can make the increased flight rate happen, though he acknowledged its difficulty.
Ars Technica’s Eric Berger offered a more positive reaction: “Isaacman has been quite good about saying uncomfortable truths about NASA and Artemis out loud. He has clearly diagnosed some of the major issues facing the space agency, not flinched from them, and is trying to address them.”
As it turns out, Sen. Ted Cruz’s (R-Texas) Senate Commerce Committee has passed a version of the latest NASA Authorization bill that fully endorses Isaacman’s plan to revamp the Artemis program. That all but guarantees that NASA is free to proceed without political interference.
Even Garver was impressed, so much so that she did a complete 180 on her assessment of Isaacman’s plan. She called the reauthorization “a significant and extremely positive development,” on X and said Isaacman’s “credibility, willingness to go public with existing program’s shortcomings and crafting a plan giving [the Space Launch System] a chance to improve, while allowing competition worked! Promising indeed!”
Isaacman has proven himself to be a political jedi master as well as an entrepreneur and engineer. But now comes the hard part.
The first part of success will consist of the upcoming Artemis missions occurring on or at least close to the times they are scheduled to occur. The second part will be at least a good start at constructing the lunar base. Both will mean that the return to the moon, long dreamed of, is a reality and not just an aspiration.
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From AIAA “Daily Launch” email newsletter 3-9-2026, following the link to a Space.com article:
NASA wants to accelerate its Artemis missions to the moon. It will need to drop some big hardware to do it.
By Josh Dinner published 3 days ago
Some major projects might be left half complete after this latest shakeup.
NASA Administrator Jared Isaacman recently announced a significant restructuring of the Artemis program, and how the agency intends to return astronauts to the moon.
The new plan shortens the time between missions and redraws the map of which launches will achieve various program milestones. Nothing will change for Artemis 2, which may lift off in a matter of weeks, carrying four astronauts on a 10-day flight around the moon and back to Earth. Every mission after Artemis 2, however, has been adjusted.
The programmatic shuffle is rendering parts of the old Artemis plan obsolete, leaving major ground hardware half-built and an uncertain future for the Gateway moon-orbiting space station under development.
Isaacman announced the changes during a press conference on Feb. 27, citing unacceptable wait times between missions for Artemis' Space Launch System (SLS) rocket and an increased risk of relying on unproven technologies to carry out mission-critical objectives like landing astronauts safely on the lunar surface.
The Artemis 2 SLS is currently undergoing repairs in the Vehicle Assembly Building (VAB) at NASA's Kennedy Space Center in Florida, with a potential rollback to its launch pad in time for a launch window that opens April 1. Artemis 2 will bethe first crewed flight of the Orion spacecraft and the first return of astronauts to lunar space in more than half a century. Under the previous framework, it was meant to be followed by Artemis 3 in 2028, which would carry out the program's first moon landing with astronauts aboard SpaceX's Starship vehicle.
For Artemis 4, NASA planned to upgrade to the SLS Block 1B, which features a design powerful enough to launch elements of the Gateway space station intended for lunar orbit. Beginning with Artemis 4, NASA aimed to use the Gateway outpost around the moon for deep-space science and as an orbital layover stop where Orion and the program's lunar lander could dock to transfer crews headed down to the surface. Gateway, however, is nowhere to be found in any of NASA's recent Artemis updates.
Under NASA's new plan, there will be no SLS Block 1B. In the hope of shortening launch cadences from the current 3.5-year interval to the desired 10 months, SLS is being standardized into a single configuration. Instead of relying on SLS' current Interim Cryogenic Propulsion upper stage, NASA is reportedly considering converting United Launch Alliance's Centaur V upper stage for use on SLS for all Artemis launches after Artemis 3.
The revised Artemis program is now targeting 2027 for the launch of Artemis 3, but instead of landing on the moon, the mission will fly to low Earth orbit for rendezvous and docking maneuvers with either or both of the Artemis program's contracted moon landers — SpaceX's Starship and Blue Origin's Blue Moon spacecraft — depending on their relative readiness for orbital missions.
NASA partnered with SpaceX for Starship to serve as the lander for Artemis 3 and 4 and contracted Blue Moon for Artemis 5. But the agency is now signaling that it's ready to fly Artemis 3 with whichever lander can be made safely available when launch time rolls around.
With Artemis 3 turned into a lunar landing stepping stone around Earth, Artemis 4 has been tapped as the program's first crewed landing on the moon, which NASA still hopes to accomplish in 2028, with a possible second moon landing that same year on Artemis 5.
It's a major reshaping of Artemis' original mission progression, but the plan has been purposed to maximize both crew safety and NASA's chances of success, according to Isaacman. The shakeup doesn't come without some sacrifice, though.
Gateway's fate remains undetermined under NASA's new plan. Many components of Gateway are already in various states of assembly, but there is now no rocket to launch some of them once they're ready and no missions yet assigned to rendezvous with the proposed outpost. Congress advanced a revised NASA authorization bill on Wednesday (March 4) that supports many of Isaacman's proposed changes to the Artemis program, but only requires he brief lawmakers on Gateway's status within a few months' of the bill's passing.
If Gateway is on the chopping block, as seems likely, there is potential for its existing hardware to be repurposed for use in a possible base on the lunar surface, which has been a longstanding component of the Artemis program's goals and NASA's vision for a sustained human presence on the moon. One of the revisions in the authorization bill even grants the NASA administrator the freedom to "repurpose, reprogram, reconfigure, or reassign existing programs, platforms, modules, or hardware originally developed for other programs" in order to ensure that the space agency's Artemis goals are successful.
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My take:
This is the first of 3 postings regarding Isaacman’s major shakeups at NASA.
GW
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Last edited by GW Johnson (Today 09:09:45)
GW Johnson
McGregor, Texas
"There is nothing as expensive as a dead crew, especially one dead from a bad management decision"
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From AIAA “Daily Launch” email newsletter 3-9-2026, following the link to a Spaceflight Now.com article:
NASA contract confirms selection of ULA’s Centaur 5 as new upper stage for the SLS rocket
March 7, 2026 Will Robinson-Smith
NASA officially selected United Launch Alliance’s Centaur 5 as the upper stage for its Space Launch System rocket starting with the Artemis 4 mission, scheduled to launch no earlier than early 2028.
The Centaur 5 was developed as the upper stage of ULA’s Vulcan rocket. The launch vehicle flew four times since its debut in January 2024 and the upper stage performed well across all flights.
The news, disclosed in contract documents published on Friday, comes one week after NASA Administrator Jared Isaacman announced that the agency would move towards a “standardization of the [Space Launch System rocket] fleet to… a near-Block 1 configuration.”
“The idea is we want to reduce complexity to the greatest extent possible,” Isaacman said during a briefing at the Kennedy Space Center on Feb. 27. “We want to accelerate manufacturing, pull in the hardware, and increase launch rate, which obviously has a direct safety consideration to it as well.”
Originally, NASA planned to launch the first three missions for the Artemis program using ULA’s Interim Cryogenic Propulsion Stage (ICPS), a modified version of its Delta 4 Cryogenic Second Stage, and then transition to the Exploration Upper Stage (EUS), built by Boeing, beginning with the Artemis 4 mission.
NASA, under Isaacman’s leadership, decided to move away from those plans due to cost and schedule overruns.
Long before this decision, Tory Bruno, ULA’s President and CEO at the time, was asked during a reporter roundtable in December 2024 about how the company would handle a theoretical change in the architecture for the SLS rocket. The question came up a month after President Donald Trump was elected to a second term, which sparked discussions of whether or not the SLS plans at the time might change.
“The Exploration Upper Stage is a very, very large upper stage. It’s much larger than the Interim Cryogenic Upper Stage that we’re providing now. It’s larger than a Centaur 5,” Bruno said. “If the government wants to change something in the architecture of SLS, they would tell us and we would tell them what we could do.”
That ‘what if?’ scenario is now reality.
In its procurement statement, NASA said its intention is to issue a sole source contract to ULA, meaning it’s the only upper stage being considered for this new iteration of the SLS rocket. An eight-page supporting document from NASA’s Marshall Space Flight Center (MSFC) in Huntsville, Alabama, was published to document the reasoning for its decision.
Among the stated reasons are the decades-long heritage of the RL10 engine, which has matured over time; the ability of the Centaur 5 to use the interfaces available on the Mobile Launcher 1 (ML1) along with the propulsion commodities of liquid oxygen and liquid hydrogen; and the experience of ULA’s teams working with NASA’s Exploration Ground Systems (EGS) at the Kennedy Space Center and elsewhere in the country.
They also noted that with the Centaur 3 upper stage achieving certification to launch humans as part of the Commercial Crew Program, there are a lot of common features with the Centaur 5.
“This approach leverages current support infrastructure and will use, with relatively minor modifications, an existing ULA upper stage,” NASA said. “All other alternative solutions fail to meet the performance requirements, would require significant modifications to hardware that is still under-development, or would require the development of new hardware that does not currently exist.”
NASA also said a time constraint to this decision caused them to select ULA as its sole choice.
“The NASA Kennedy Space Center (KSC) need date for processing is projected to be nine months prior to a launch,” NASA said. “Award to another source would cause unacceptable delays to current launch schedules.
“These delays would derive from the procurement process, on/off ramping of new contractor personnel, the potential need for reworked activities, as well as efforts necessary to satisfy SLS technical and programmatic drivers.”
The other upper stage that may have been in contention was from Blue Origin’s New Glenn rocket. Besides not having the previously stated advantages from NASA’s perspective, the agency also expressed concerns with the modifications needed to adopt Glenn Stage 2 for the ML1.
“Using the NGUS would require significant modifications to both the stage and the EGS infrastructure. For example, using NGUS would require relocating the Mobile Launcher Crew Access Arm and modification to the upper stage umbilical retraction mechanism,” NASA said.
“The stage could be shortened to meet VAB height constraints but would require full scale development and testing to qualify the stage for the shorter configuration. Full scale testing/requalification would result in unacceptable schedule impacts and additional cost risk to the SLS Program.”
What happened to the Exploration Upper Stage?
The original plan to use an EUS-enabled rocket would’ve enabled what NASA called “more ambitious missions” to the Moon, given that it would allow for the delivery of up to 11 metric tons more mass to the lunar surface under the Block 1B configuration as compared to the ICPS-powered Block 1 rocket.
However, a 2024 report from NASA’s Office of Inspector General found that, despite the SLS Block 1B being in development since 2014 and moving the first flight from Artemis 3 to Artemis 4, it continued to be behind schedule due in part to what the OIG called “quality control issues” at the Michoud Assembly Facility (MAF) in Louisiana.
“We project SLS Block 1B costs will reach approximately $5.7 billion before the system is scheduled to launch in 2028,” the report stated. “This is $700 million more than NASA’s 2023 Agency Baseline Commitment, which established a cost and schedule baseline at nearly $5 billion.
“EUS development accounts for more than half of this cost, which we estimate will increase from an initial cost of $962 million in 2017 to nearly $2.8 billion through 2028.”
The mid-2024 report also noted that at the time, delivery of the EUS to NASA was “delayed from February 2021 to April 2027.” That put the Artemis 4 flight, then projected for September 2028, to become further delayed.
Back in late September 2025, Spaceflight Now spoke with Sharon Cobb, the Associate Program manager for SLS at Boeing, about the Artemis 2 mission as well as the progress on the EUS.
“We’ve been working very diligently on Exploration Upper Stage. I was just at MAF last week and was able to see the liquid oxygen tank has been welded and tested,” Cobb said. “We’ve also got barrels in work there that are about to be welded for the flight unit. The LOX tank is a structural test article. So, we’re making really good progress on developing that Exploration Upper Stage.
Like with the core stage that launched the Artemis 1 mission, the plan was to perform what’s called a ‘green run’ with the EUS at NASA’s Stennis Space Center in Mississippi. That would include a full fueling of the upper stage and a full duration static fire test of the four RL10 engines as well.
Presumably, with this new direction for the SLS rocket, that will no longer take place, though NASA hasn’t specifically commented on what will happen with the EUS hardware currently in flow.
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My take:
This is the second of 3 postings regarding Isaacman’s major shakeups at NASA
GW
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Last edited by GW Johnson (Today 09:10:51)
GW Johnson
McGregor, Texas
"There is nothing as expensive as a dead crew, especially one dead from a bad management decision"
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From AIAA “Daily Launch” email newsletter 3-9-2026, just the summary of an ARS Technica article:
ARS TECHNICA
With Gateway likely gone, where will lunar landers rendezvous with Orion?
Last week, NASA Administrator Jared Isaacman unveiled a major shakeup in the Artemis Program. The changes focused largely on increasing the launch cadence of NASA’s large SLS rocket and putting a greater emphasis on lunar surface activities. Days later, the US Senate indicated that it broadly supported these plans. Which lander will be used to take astronauts down to the lunar surface from an orbit around the Moon and back up to rendezvous with Orion?
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My take:
The rumors have proved to be true. Gateway is essentially out, SLS Block 1B and Block 2 are out, and there will only be a slight upgrade to SLS Block 1 with the Centaur-5 replacing the Interim Upper Stage (the second stage of Delta-4). Artemis will rendezvous with landers and do its landings from some lunar orbit that the SLS Block-1 can reach with Orion atop it. That is likely some elliptic capture orbit, but nobody is talking about that yet. We will see whose lander “gets there” first. That will be the one they use.
Isaacman is trying to do it “right”. We will see if he can change the NASA culture back to crew lives valued more than schedule and money. He has made noises like that, but as yet I have seen no change at NASA. Artemis-2 will fly with the same flawed heat shield that surprised everyone on Artemis-1. Artemis-3 is already being built to the same flawed design. Sooner or later, the odds will bite them with that, just like they did with the flawed SRB O-ring joint design with the space shuttle.
GW
Last edited by GW Johnson (Today 09:13:58)
GW Johnson
McGregor, Texas
"There is nothing as expensive as a dead crew, especially one dead from a bad management decision"
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Sounds like they are trying to get rid of the standing support army concept as well, to go down the path of commercial industry.
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