Artemis Stuff

[Yazata]

They are conducting the Artemis II wet-dress rehearsal today, as I write this. Crew boards, all of the rocket's stages are fueled, and countdown proceeds down to launch, except without ignition.

Nasaspaceflight.com images

[Image: HAK7ccrWEAAEov4?format=jpg&name=small]

[Image: HAL0zmQWIAAvB0Q?format=jpg&name=small]

[Yazata]

Turns out that the crew wasn't aboard during the wet-dress rehearsal. They remain back in Houston. But the rest of the fueling and countdown was conducted as if it was the real thing.

An early problem was a hydrogen leak around a fueling connection. Hydrogen leaks are hard to prevent since hydrogen H2 molecules are tiny little sneaky devils that are always trying to escape, so some leakage was expected. Test conductors decided that the leak was small enough that they could proceed with the test.

Other relatively minor problems developed, most notably problems closing an access hatch. Ground closeout crews struggled with that one, causing a hold, but eventually got it sorted out.

But as the countdown approached t-5 minutes, the hydrogen leak had grown to the point where it was starting to become dangerous, so the launch rehearsal was scrubbed.

---

Update

Jared just posted this:

https://x.com/NASAAdmin/status/2018578937115271660

"With the conclusion of the wet dress rehearsal today, we are moving off the February launch window and targeting March for the earliest possible launch of Artemis II.

With more than three years between SLS launches, we fully anticipated encountering challenges. That is precisely why we conduct a wet dress rehearsal. These tests are designed to surface issues before flight and set up launch day with the highest probability of success.

During the test, teams worked through a liquid hydrogen leak at a core stage interface during tanking, which required pauses to warm hardware and adjust propellant flow. All core stage and interim cryogenic propulsion stage tanks were successfully filled, and teams conducted a terminal countdown to about T-5 minutes before the ground launch sequencer halted operations due to an increased leak rate. Additional factors included extended Orion closeout work, intermittent ground audio dropouts, and cold-weather impacts to some cameras, along with the successful demonstration of updated Orion closeout purge procedures to support safe crew operations.

As always, safety remains our top priority, for our astronauts, our workforce, our systems, and the public. As noted above, we will only launch when we believe we are as ready to undertake this historic mission..."

[Yazata]

After the second Artemis II wet dress rehearsal apparently went exceedingly well, they were shooting for an Artemis II launch on March 6.

Then Jared posted this...

https://x.com/NASAAdmin/status/2025231621436186837

"After overnight data showed an interruption in helium flow in the SLS interim cryogenic propulsion stage, teams are troubleshooting and preparing for a likely rollback of Artemis II to the VAB at NASAKennedy. This will almost assuredly impact the March launch window. NASA will continue to provide updates as they become available."

And he quickly followed up with this...

https://x.com/NASAAdmin/status/2025249086908125630

"As an update to my earlier post.

- The ICPS helium bottles are used to purge the engines, as well as for LH2 and LOX tank pressurization. The systems did work correctly during WDR1 and WDR2.

- Last evening, the team was unable to get helium flow through the vehicle. This occurred during a routine operation to repressurize the system.

- We observed a similar failure signature on Artemis I.

- The Artemis II vehicle is in a safe configuration, using ground ECS purge for the engines versus the onboard helium supply.

- Potential faults could include the final filter between the ground and flight vehicle, located on the umbilical, though this seems least likely based on the failure signature. It could also be a failed QD umbilical interface, where similar issues have been observed. It could also be a failed check valve onboard the vehicle, which would be consistent with Artemis I, though corrective actions were taken to minimize reoccurrence on Artemis II.

Regardless of the potential fault, accessing and remediating any of these issues can only be performed in the VAB.

As mentioned previously, we will begin preparations for rollback, and this will take the March launch window out of consideration.

I understand people are disappointed by this development. That disappointment is felt most by the team at NASA, who have been working tirelessly to prepare for this great endeavor. During the 1960s, when NASA achieved what most thought was impossible, and what has never been repeated since, there were many setbacks. One historic example is that Neil Armstrong spent less than 11 hours in space on Gemini 8 before his mission ended prematurely due to a technical issue. A little over three years later, he became the first man to walk on the Moon.

There are many differences between the 1960s and today, and expectations should rightfully be high after the time and expense invested in this program. I will say again, the President created Artemis as a program that will far surpass what America achieved during Apollo. We will return in the years ahead, we will build a Moon base, and undertake what should be continuous missions to and from the lunar environment. Where we begin with this architecture and flight rate is not where it will end.

Please expect a more extensive briefing later this week as we outline the path forward, not just for Artemis II, but for subsequent missions, to ensure NASA meets the President’s vision to return to the Moon and, this time, to stay."

[Yazata]

And here is the Artemis II SLS heading back into the barn.

The NASA VAB is impressive, and the crawler with its integral launch mount and tower is simply insane!

(NASA photo posted by Jared)

[Image: HCDL-z0XAAIqIjU?format=jpg&name=large]

[Yazata]

Jared just announced a major overhaul to the Artemis Moon program.

https://www.nasa.gov/news-release/nasa-a...hitecture/

As teams prepare to launch Artemis II in the weeks ahead, the Artemis III mission, now in 2027, will be designed to test out systems and operational capabilities in low Earth orbit to prepare for an Artemis IV landing in 2028. This new mission will endeavor to include a rendezvous and docking with one or both commercial landers from SpaceX and Blue Origin, in-space tests of the docked vehicles, integrated checkout of life support, communications, and propulsion systems, as well as tests of the new Extravehicular Activity (xEVA) suits. NASA will further define this test flight after completing detailed reviews between NASA and our industry partners. The agency will share the specific objectives for the updated Artemis III mission in the near future.

So Artemis IV will be the lunar landing, not Artemis III.

In addition to adding an additional Artemis test mission in 2027 to test docking with either the SpaceX or Blue Origin lander, depending on which one is further along a year from now, they plan changes in the SLS architecture as well. Currently they are developing a more powerful upper stage for SLS, and now it sounds like it will either be cancelled or deemphasized.

“NASA must standardize its approach, increase flight rate safely, and execute on the President’s national space policy. With credible competition from our greatest geopolitical adversary increasing by the day, we need to move faster, eliminate delays, and achieve our objectives,” said NASA Administrator Jared Isaacman. “Standardizing vehicle configuration, increasing flight rate and progressing through objectives in a logical, phased approach, is how we achieved the near-impossible in 1969 and it is how we will do it again.”

“After successful completion of the Artemis I flight test, the upcoming Artemis II flight test, and the new, more robust test approach to Artemis III, it is needlessly complicated to alter the configuration of the SLS and Orion stack to undertake subsequent Artemis missions,” said NASA Associate Administrator Amit Kshatriya. “There is too much learning left on the table and too much development and production risk in front of us. Instead, we want to keep testing like we fly and have flown. We are looking back to the wisdom of the folks that designed Apollo. The entire sequence of Artemis flights needs to represent a step-by-step build-up of capability, with each step bringing us closer to our ability to perform the landing missions. Each step needs to be big enough to make progress, but not so big that we take unnecessary risk given previous learnings. Therefore, we want to fly the landing missions in as close to the same Earth ascent configuration as possible – this means using an upper stage and pad systems in as close to the ‘Block 1’ configuration as possible. We will work with our partners that have been developing the evolved block configuration of these systems to take proper actions to align their efforts towards this goal and announce the details of those changes once they are finalized. We will take a similar approach to in-space, landing, and surface EVA operations as well, as we evolve the mission sequence in the spirit of the Apollo mindset, which was obsessed with system reliability and crew safety as the keys to mission success.”