SLS Roll-out

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Boac
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SLS Roll-out

#1 Post by Boac » Tue Mar 15, 2022 9:32 pm

Expected to move tomorrow with a dummy launch procedure on 17th.

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Re: SLS Roll-out

#2 Post by PHXPhlyer » Sun Apr 03, 2022 7:45 pm

NASA’s Artemis I mega moon rocket test postponed

https://www.cnn.com/2022/04/03/world/na ... index.html

The final, crucial prelaunch test of NASA’s Artemis I mission to the moon was halted Sunday due to issues that prevented the safe loading of propellants into the mega rocket.

The agency’s next opportunity to begin fueling the 322-foot-tall (98-meter-tall) Artemis I rocket stack, including NASA’s Space Launch System and Orion spacecraft, is on Monday. Teams are meeting to assess whether resuming the test tomorrow is possible, and NASA will provide another update today at 5:30 p.m.

The test, known as the wet dress rehearsal, began on Friday afternoon at 5 p.m. ET.

The wet dress rehearsal simulates every stage of launch without the rocket actually leaving the launchpad. This includes powering on the SLS rocket and Orion spacecraft, loading supercold propellant into the rocket’s tanks, going through a full countdown simulating launch, resetting the countdown clock and draining the rocket tanks.

Operations were stopped on Sunday before loading propellants into the core stage of the rocket “due to loss of ability to pressurize the mobile launcher,” according to an update shared by the agency.

Prime and redundant supply fans for the mobile launcher weren’t working properly.

“The fans are needed to provide positive pressure to the enclosed areas within the mobile launcher and keep out hazardous gases. Technicians are unable to safely proceed with loading the propellants into the rocket’s core stage and interim cryogenic propulsion stage without this capability.”

Prior to this issue on Sunday afternoon, Artemis I weathered a powerful thunderstorm at Kennedy Space Center on Saturday.

Four lightning strikes hit the lightning towers within the perimeter of Launchpad 39B. While the first three were low-intensity strikes to tower two, the fourth strike was much more intense and hit tower one.

When these strikes occurred, the Orion spacecraft and SLS rocket core stage were powered up. The rocket’s interim cryogenic propulsion stage and boosters were not.

The fourth lightning strike was “the strongest we have seen since we installed the new lightning protection system,” tweeted Jeremy Parsons, deputy manager of the exploration ground systems program at NASA’s Kennedy Space Center, who has been providing regular updates all weekend. “It hit the catenary wire that runs between the 3 towers. System performed extremely well & kept SLS and Orion safe. Glad we enhanced protection since Shuttle!”

Each of the towers are topped with a fiberglass mast and series of overhead, or catenary, wires and conductors that help divert lightning strikes away from the rocket, Parsons explained. This new system provided more shielding than the one used during the Shuttle program. It also has an array of sensors that can determine the condition of the rocket after lightening strikes, preventing days of delays caused when teams have to assess the rocket.

Despite the strikes and delays, team were prepared to carry on with the wet dress rehearsal Sunday until they encountered the tanking issue.

Parsons shared a reminder that this is the point of the wet dress rehearsal – working out the kinks of a new system before launch day.

“A nice thing about this being a test, and not launching today, is that we have flexibility with the test window to work through first time issues,” Parsons tweeted.

The results of the wet dress rehearsal will determine when the uncrewed Artemis I will launch on a mission that goes beyond the moon and returns to Earth. This mission will kick off NASA’s Artemis program, which is expected to return humans to the moon and land the first woman and the first person of color on the lunar surface by 2025.

What to expect next
When the wet dress rehearsal resumes, it will involve loading the rocket with more than 700,000 gallons (3.2 million liters) of supercold propellant – the “wet” in wet dress rehearsal – and then the team will go through all the steps toward launch.

“Some venting may be seen during tanking,” according to the agency, but that’s about it for visible action at the launchpad.

The team members will count down to within a minute and 30 seconds before launch and pause to ensure they can hold launch for three minutes, resume and let the clock run down to 33 seconds, and then pause the countdown.

Then, they will reset the clock to 10 minutes before launch, go through the countdown again and end at 9.3 seconds, just before ignition and launch would occur. This simulates what is called scrubbing a launch, or aborting a launch attempt, if weather or technical issues would prevent a safe liftoff.

At the end of the test, the team will drain the rocket’s propellant, just as it would during a real scrub.

Depending on the outcome of the wet dress rehearsal, the uncrewed mission could launch in June or July.

During the flight, the uncrewed Orion spacecraft will launch atop the SLS rocket to reach the moon and travel thousands of miles beyond it – farther than any spacecraft intended to carry humans has ever traveled. This mission is expected to last for a few weeks and will end with Orion splashing down in the Pacific Ocean.

Artemis I will be the final proving ground for Orion before the spacecraft carries astronauts to the moon, 1,000 times farther from Earth than where the International Space Station is located.

After the uncrewed Artemis I flight, Artemis II will be a crewed flyby of the moon, and Artemis III will return astronauts to the lunar surface. The time line for the subsequent mission launches depends on the results of the Artemis I mission.

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Re: SLS Roll-out

#3 Post by PHXPhlyer » Tue Apr 05, 2022 3:13 am

NASA’s Artemis I mega moon rocket test stopped for second time

https://www.cnn.com/2022/04/04/world/na ... index.html

CNN

The second attempt at the final, crucial prelaunch test for NASA’s Artemis I mission to the moon was scrubbed on Monday.

The wet dress rehearsal, as NASA calls it, simulates every stage of launch without the rocket actually leaving the launchpad.

This includes powering on the 322-foot-tall (98-meter-tall) Space Launch System rocket and Orion spacecraft, loading supercold propellant into the rocket’s tanks, going through a full countdown simulating launch, resetting the countdown clock and draining the rocket tanks.

The test was originally scheduled to be completed on Sunday but was put on hold before the propellant was loaded. That was due to problems with two fans used to provide pressure to the mobile launcher – the movable tower which the rocket sits upon before it lifts off.

NASA said Monday it was able overnight to resolve the malfunction of the fans, which are needed to pressurize enclosed areas inside the launcher and keep out hazardous gases.

However, the rehearsal was stopped for the second time Monday due to a vent valve issue, NASA announced via Twitter.

“Due the vent valve issue, the launch director has called off the test for the day. The team is preparing to offload LOX and will begin discussing how quickly the vehicle can be turned around for the next attempt. A lot of great learning and progress today.”


Sunday’s delay came after the rocket weathered four lightening strikes during a powerful thunderstorm at Kennedy Space Center on Saturday. However, the fan issue that forced Sunday’s delay was not thought to be connected to the storm, NASA said.

The results of the wet dress rehearsal will determine when the uncrewed Artemis I will launch on a mission that goes beyond the moon and returns to Earth. The uncrewed mission is expected to launch in June or July.

This mission will kick off NASA’s Artemis program, which is expected to return humans to the moon and land the first woman and the first person of color on the lunar surface by 2025.

During the flight, the uncrewed Orion spacecraft will launch atop the SLS rocket to reach the moon and travel thousands of miles beyond it – farther than any spacecraft intended to carry humans has ever traveled. This mission is expected to last for a few weeks and will end with Orion splashing down in the Pacific Ocean.

Artemis I will be the final proving ground for Orion before the spacecraft carries astronauts to the moon, 1,000 times farther from Earth than where the International Space Station is located.

After the uncrewed Artemis I flight, Artemis II will be a crewed flyby of the moon, and Artemis III will return astronauts to the lunar surface. The time line for the subsequent mission launches depends on the results of the Artemis I mission.

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Re: SLS Roll-out

#4 Post by PHXPhlyer » Fri Apr 08, 2022 4:50 pm

NASA to begin third attempt at crucial moon mission test on Saturday

https://www.cnn.com/2022/04/08/world/na ... index.html

A third attempt at a crucial prelaunch test for NASA’s Artemis I mission to the moon will begin on Saturday, after the two previous tries were called off, the agency said in a news release.

The wet dress rehearsal, which simulates every stage of launch without the rocket actually leaving the launchpad, will begin at 5 p.m. ET on Saturday and is expected to go until 2:40 p.m. ET Monday, according to the release.

The test is an important step in the first phase of NASA’s Artemis program, which is expected to return humans to the moon and land the first woman and the first person of color on the lunar surface by 2025.

Blue sky and clouds serve as the backdrop for a sunrise view of the Artemis I Space Launch System (SLS) and Orion spacecraft at Launch Pad 39B at NASA's Kennedy Space Center in Florida on March 23, 2022. The SLS and Orion atop the mobile launcher were transported to the pad on crawler-transporter 2 for a prelaunch test called a wet dress rehearsal. Artemis I will be the first integrated test of the SLS and Orion spacecraft. In later missions, NASA will land the first woman and the first person of color on the surface of the Moon, paving the way for a long-term lunar presence and serving as a steppingstone on the way to Mars.
NASA still hopes to launch moon mission in June despite two scrubbed trials
The wet dress rehearsal was originally scheduled to be completed last Sunday but was put on hold before the propellant was loaded. That was due to problems with two fans used to provide pressure to the mobile launcher – the movable tower the rocket sits upon before it lifts off.

The next day, NASA said it was able to resolve the malfunction of the fans, which are needed to pressurize enclosed areas inside the launcher and keep out hazardous gases.

The test was attempted again Monday but was stopped before it was completed because of an issue with a panel on the mobile launcher that controls the core stage vent valve, said Charlie Blackwell-Thompson, Artemis launch director for NASA’s Exploration Ground Systems program. The valve relieves pressure from the rocket’s core stage while tanking of the propellant is underway, according to NASA.

The results of the wet dress rehearsal will determine when Artemis I will launch on a mission that goes beyond the moon and returns to Earth.

During the flight, the uncrewed Orion spacecraft will launch atop the SLS rocket to reach the moon and travel thousands of miles beyond it – farther than any spacecraft intended to carry humans has ever traveled. This mission is expected to last for a few weeks and will end with Orion splashing down in the Pacific Ocean.

Artemis I will be the final proving ground for Orion before the spacecraft carries astronauts to the moon, 1,000 times farther from Earth than where the International Space Station is located.

After the uncrewed Artemis I flight, Artemis II will be a crewed flyby of the moon, and Artemis III will return astronauts to the lunar surface. The time line for the subsequent mission launches depends on the results of the Artemis I mission.

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Re: SLS Roll-out

#5 Post by PHXPhlyer » Sat Apr 09, 2022 3:36 pm

Are we seeing a pattern developing? :-?

NASA’s third attempt at crucial moon mission test delayed to Tuesday due to malfunctioning valve

https://www.cnn.com/2022/04/09/world/na ... index.html

NASA announced Saturday that a crucial moon mission test has again been delayed and is now scheduled to begin on Tuesday.

The space agency was scheduled to begin a prelaunch test for NASA’s Artemis I mission to the moon. The Artemis program is NASA’s first mission to the moon since 1972.

On the NASA blog, the agency said the test was pushed due to a malfunctioning valve.

“Engineers have identified a helium check valve that is not functioning as expected, requiring these changes to ensure safety of the flight hardware,” the agency said. Engineers at the Kennedy Space Center will evaluate the valve and replace it if needed, the agency added.

The critical prelaunch test is known as a “wet dress rehearsal” and simulates every stage of launch without the rocket actually leaving the launchpad. The Space Launch System (SLS) rocket and Orion spacecraft will be powered on, supercold propellant will be loaded into the rocket’s tanks (the “wet” in wet dress rehearsal), and NASA’s team will go through a full countdown simulating the launch.

Blue sky and clouds serve as the backdrop for a sunrise view of the Artemis I Space Launch System (SLS) and Orion spacecraft at Launch Pad 39B at NASA's Kennedy Space Center in Florida on March 23, 2022. The SLS and Orion atop the mobile launcher were transported to the pad on crawler-transporter 2 for a prelaunch test called a wet dress rehearsal. Artemis I will be the first integrated test of the SLS and Orion spacecraft. In later missions, NASA will land the first woman and the first person of color on the surface of the Moon, paving the way for a long-term lunar presence and serving as a steppingstone on the way to Mars.
NASA still hopes to launch moon mission in June despite two scrubbed trials
This is the third time the wet dress rehearsal has been delayed. Originally scheduled for February, the rehearsal was delayed once for further testing and then again for issues involving propellant loading. The test is essential to determining when exactly NASA will conduct its Artemis I mission, in which an uncrewed spacecraft will reach the moon and then travel thousands of miles beyond it.

NASA has said that it plans to launch the mission in June or July, depending on the results of the wet dress rehearsal. The first step will be an uncrewed mission – Artemis I. Then, Artemis II will take astronauts on a crewed flyby of the moon, and Artemis III will bring NASA astronauts to land on the lunar surface for the first time in fifty years.

The agency hopes to land the first woman and the first person of color on the lunar surface by 2025.

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Re: SLS Roll-out

#6 Post by PHXPhlyer » Fri Apr 15, 2022 1:31 am

Third Time's Not the Charm :-o [-X

NASA’s Artemis mega moon rocket’s crucial test experiences leak issue, delays


The third attempt at a final prelaunch test for NASA’s Artemis I mega moon rocket began Thursday morning, but the trial hit some snags and ended prematurely at 5:10 p.m. ET.

The agency will host a news conference on Friday to share updates and next steps for the test.

The mission team had been attempting to fuel the 322-foot-tall (98-meter-tall) Artemis I rocket stack, including NASA’s Space Launch System and Orion spacecraft, at Kennedy Space Center in Florida, but encountered a number of delays.

“The team will not conduct the terminal countdown activities today as planned and will assess next steps after today’s operations,” according to a tweet from Jeremy Parsons, deputy manager of the Exploration Ground Systems program at Kennedy Space Center.

The rocket remains stable and in a safe configuration, according to the agency.

NASA's new Moon rocket at Kennedy Space Center making its first journey to the launch pad. Consisting of NASA's Space Launch System (SLS) rocket and Orion spacecraft, the Artemis I rocket is ready to roll March 17 to Launch Complex 39B for its wet dress rehearsal on March 17, 2022 at Kennedy Space Center in Merritt Island, FL for a launch targeted for April 1. The dress rehearsal will test the ability to load nearly 700,000 gallons of cryogenic, propellants into the rocket while on the launch pad and practice the launch countdown, and test the ability to drain propellants to show standing down safety.
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The crucial test, known as the wet dress rehearsal, simulates every stage of launch without the rocket actually leaving the launchpad. This includes loading propellant, going through a full countdown simulating launch, resetting the countdown clock and draining the rocket tanks.

The process was previously adjusted in response to an issue encountered over the weekend during preparations for this attempt.

“Any new rocket that comes forward in a new program like this kind of goes through these updates and understanding how the rocket is performing,” said Tom Whitmeyer, deputy associate administrator for exploration systems development at NASA Headquarters, during a news conference Monday. “And that’s the type of thing that we’re going through right now.”

A modified test
The issue engineers identified over the weekend is a malfunctioning helium check valve. Helium is used to purge the engine before loading supercold propellant – the wet in wet dress rehearsal – during fueling. Check valves allow gas or liquid to flow in one direction to prevent backflow. In this case, the part that isn’t working is about 3 inches (7.6 centimeters) long and keeps helium from flowing back out of the rocket.

The valve is difficult to reach while the rocket sits on the launchpad, but it can be replaced or fixed after the run-through is complete. The modified version of the wet dress rehearsal is still necessary, however, to ensure the safety of the rocket’s flight hardware.

The modified test will take the strain off of the valve and the upper rocket stage with minimal propellant operations. Previously, the team had planned to fully fuel the core and upper stages of the rocket, but the valve issue prevents that step from taking place during this test. Assessments will be made to see whether further tests are needed.

The rocket and spacecraft were powered up Wednesday night, and the team conducted a meeting at 6 a.m. ET Thursday to assess the weather and review the status of operations. The team extended a hold, which was expected to last an hour and a half to two hours, after experiencing “an issue with an outage at an off-site vendor of gaseous nitrogen used inside the rocket before propellant loading,” according to an update from NASA officials. This issue is similar to one experienced during a previous attempt on April 4.

The gaseous nitrogen is used to purge oxygen from the rocket prior to fueling, and it’s a safety measure. The team was able to reestablish the supply of gaseous nitrogen and begin fueling after 8 a.m. ET.

Fueling begins with chilling liquid oxygen lines for the core stage of the rocket. Then, liquid oxygen and liquid hydrogen fill the core stage through these lines, getting topped off and replenished as some of the supercold propellant boils off, according to the agency. The team will chill propellant lines for the rocket’s upper stage as well, but not release any propellant due to the existing valve issue.

The Artemis rocket core stage can hold 198,000 gallons (900,126 liters) of liquid oxygen that is cooled to negative 297 degrees Fahrenheit (negative 182 degrees Celsius). A total of 537,000 gallons of propellant will be loaded into the rocket when the core stage is fully fueled.

The team experienced several stops and starts while loading the liquid oxygen and liquid hydrogen. The latest issue was a leak “identified in the tail service mast umbilical,” connected to the rocket’s core stage and located at the base of the mobile launcher the rocket sits atop.

“Hydrogen is extremely hazardous, cold, and a small molecule that is known for leaking. All of these systems have been sealed, leak checked and tested to the highest extent possible prior to wet dress rehearsal,” according to a tweet from Jeremy Parsons, deputy manager of the Exploration Ground Systems program at Kennedy Space Center.

“Under the unique operating conditions with the rocket we are prepared and know leaks are a realistic possibility. We have amazing hazardous gas and leak detection systems that keep the rocket safe and alert us to conditions outside of normal parameters.”

The team will continue chilling down the hydrogen lines connected to the upper stage of the rocket to collect more data, and there are no plans to load liquid hydrogen or liquid oxygen into the upper stage tanks.

The core stage liquid hydrogen tank was about 5% full, and the liquid oxygen tank was 49% full. The propellant will be drained, and the team will inspect the leak and come up with a plan to move ahead.

Learning valuable lessons
Once this test is complete, the Artemis I rocket will be rolled back into the Vehicle Assembly Building at the space center.

The previous attempts at the wet dress rehearsal have already provided valuable insight, officials said, even as the team has worked through various issues.

This sequence shows how the nucleus of Comet C/2014 UN271 (Bernardinelli-Bernstein) was isolated from a vast shell of dust and gas surrounding the solid icy nucleus. On the left is a photo of the comet taken by the NASA Hubble Space Telescope's Wide Field Camera 3 on January 8, 2022. A model of the coma (middle panel) was obtained by means of fitting the surface brightness profile assembled from the observed image on the left. This allowed for the coma to be subtracted, unveiling the point-like glow from the nucleus. Combined with radio telescope data, astronomers arrived at a precise measurement of the nucleus size. That's no small feat from something 3 billion miles away. Though the nucleus is estimated to be as large as 85 miles across, it is so far away it cannot be resolved by Hubble. Its size is derived from its reflectivity as measured by Hubble. The nucleus is estimated to be as black as charcoal. The nucleus area is gleaned from radio observations.
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While the exact issues identified during the test attempts weren’t anticipated, it’s part of the process when testing out a new rocket.

“I can say that these will probably not be the last challenges we’ll encounter,” said Mike Sarafin, Artemis mission manager at NASA Headquarters, during the conference. “But I’m confident that we have the right team in place and the ability to rally around those problems and overcome them is something that that we take pride in.”

The results of the wet dress rehearsal will determine when the uncrewed Artemis I will launch on a mission that goes beyond the moon and returns to Earth. This mission will kick off NASA’s Artemis program, which is expected to return humans to the moon and land the first woman and the first person of color on the lunar surface by 2025.

The current launch window possibilities include June 6 through June 16, June 29 through July 17 and July 26 through August 9, Sarafin said.

PP

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Re: SLS Roll-out

#7 Post by PHXPhlyer » Wed Jun 15, 2022 5:45 pm

NASA sets date for next (4th) go at mega moon rocket’s crucial prelaunch test

https://www.cnn.com/2022/06/15/world/na ... index.html

CNN

The Artemis I mega moon rocket is ready for its fourth attempt at a final prelaunch test, according to an update from NASA officials on Wednesday.

The crucial test, known as the wet dress rehearsal, simulates every stage of launch without the rocket leaving the launchpad at Kennedy Space Center in Florida.

This process includes loading supercold propellant, going through a full countdown simulating launch, resetting the countdown clock and draining the rocket tanks.

The results of the wet dress rehearsal will determine when the uncrewed Artemis I will launch on a mission that goes beyond the moon and returns to Earth. This mission will kick off NASA’s Artemis program, which is expected to return humans to the moon and land the first woman and the first person of color on the lunar surface by 2025.

Three previous attempts at the wet dress rehearsal in April were unsuccessful, concluding before the rocket could be fully loaded with propellant due to various leaks, which according to NASA have since been corrected.

The NASA team rolled the 322-foot-tall (98-meter-tall) Artemis I rocket stack, including the Space Launch System and Orion spacecraft, back to the launchpad at Kennedy Space Center in Florida on June 6.

Wet dress rehearsal: What to expect
The Artemis rocket will begin its next attempt at the wet dress rehearsal Saturday at 5 p.m. ET. with a “call to stations,” when all of the teams associated with the mission report that they’re ready for the test to begin.

Preparations over the weekend will set up the Artemis team to start loading propellant into the rocket’s core stage and upper stage on Monday, June 20.

The test will air live on NASA’s website, with commentary, beginning at 7 a.m. ET on Monday.

A two-hour test window will begin in the afternoon, with the Artemis team targeting the first countdown at 2:40 p.m. ET.

First, they will go through a countdown to 33 seconds before launch, then stop the cycle. The clock will be reset, then the countdown will resume again and run until about 10 seconds before a launch would occur.

The previous wet dress rehearsal attempts have already completed many objectives on the list to prepare the rocket for launch, said Charlie Blackwell-Thompson, Artemis launch director for NASA’s Exploration Ground Systems Program, during a news conference on Wednesday.

“We hope to finish them off this time around and get through the cryogenic loading operations along with terminal count,” she said. “Our team is ready to go and we’re looking forward to getting back to this test.”

The mission team is now looking at several possible launch windows for sending Artemis I on its journey to the moon in late summer: August 23 to August 29, September 2 to September 6 and beyond.

Once the Artemis rocket stack completes its wet dress rehearsal, it will roll back into the space center’s Vehicle Assembly Building to wait for launch day.

There is a long history behind the arduous process to test new systems before launching a rocket, and what the Artemis team is facing is similar to what the Apollo and shuttle era teams experienced, including multiple test attempts and delays before launch.

“There’s not a single person on the team that shies away from the responsibility that we have to manage ourselves and our contractors and to deliver, and deliver means meeting those flight test objectives for (Artemis I), and meeting the objectives of the Artemis I program,” said Jim Free, associate administrator for NASA’s Exploration Systems Development Mission Directorate, during the news conference.

PP

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Re: SLS Roll-out

#8 Post by PHXPhlyer » Mon Jun 20, 2022 4:09 pm

Watch the Artemis moon rocket's final prelaunch test on the launchpad
Updated 6/20/22

https://edition.cnn.com/2022/06/20/worl ... index.html

(CNN)The Artemis I mega moon rocket is ready to fuel up.

The fourth attempt of a final prelaunch test started on Saturday, with fueling of the rocket expected to begin Monday morning.
The crucial test, known as the wet dress rehearsal, simulates every stage of launch without the rocket leaving the launchpad at Kennedy Space Center in Florida.
This process includes loading supercold propellant, going through a full countdown simulating launch, resetting the countdown clock and draining the rocket tanks.

The results of the wet dress rehearsal will determine when the uncrewed Artemis I will launch on a mission that goes beyond the moon and returns to Earth. This mission will kick off NASA's Artemis program, which is expected to return humans to the moon and land the first woman and first person of color on the lunar surface by 2025.
Three previous attempts at the wet dress rehearsal in April were unsuccessful, concluding before the rocket could be fully loaded with propellant due to various leaks. These have since been corrected, NASA says.
The NASA team rolled the 322-foot-tall (98-meter-tall) Artemis I rocket stack, including the Space Launch System and Orion spacecraft, back to the launchpad at Kennedy Space Center in Florida on June 6.
Wet dress rehearsal: What to expect
The wet dress rehearsal began at 5 p.m. ET Saturday with a "call to stations" -- when all of the teams associated with the mission arrive at their consoles and report they're ready for the test to begin and kick off a two-day countdown.
Preparations over the weekend will set up the Artemis team to start loading propellant into the rocket's core and upper stages.
There is currently a live view of the rocket on NASA's website, with intermittent commentary.
Tanking was on hold Monday morning because of an issue identified with the backup supply of gaseous nitrogen. The launch team replaced the valve causing the issue. In order to make sure the backup supply is functioning as expected, it has been swapped in as the primary supply for today's test.
The hold lifted at 9:28 a.m. ET. Liquid oxygen, cooled to minus 297 degrees Fahrenheit (minus 182 degrees Celsius), and liquid hydrogen will fill the tanks. Venting may be visible as the tanks fill.
A two-hour test window will begin later, with the Artemis team targeting the first countdown at 4:38 p.m. ET. due to the tanking delay.


First, team members will go through a countdown to 33 seconds before launch, then stop the cycle. The clock will be reset; then the countdown will resume again and run until about 10 seconds before a launch would occur.
"During the test, the team may hold during the countdown as necessary to verify conditions before resuming the countdown, or extend beyond the test window, if needed and resources allow," according to an update on NASA's website.
The previous wet dress rehearsal attempts have already completed many objectives to prepare the rocket for launch, said Charlie Blackwell-Thompson, Artemis launch director for NASA's Exploration Ground Systems Program, during a Wednesday news conference.
"We hope to finish them off this time around and get through the cryogenic loading operations along with terminal count," she said. "Our team is ready to go, and we're looking forward to getting back to this test."
The mission team is looking at possible launch windows for sending Artemis I on its journey to the moon in late summer: August 23 to August 29, September 2 to September 6 and beyond.
Once the Artemis rocket stack completes its wet dress rehearsal, it will roll back into the space center's Vehicle Assembly Building to wait for launch day.
There is a long history behind the arduous testing of new systems before a launch, and the Artemis team faces similar experiences to those of the Apollo- and shuttle-era teams, including multiple test attempts and delays.
"There's not a single person on the team that shies away from the responsibility that we have to manage ourselves and our contractors and to deliver, and deliver means meeting those flight test objectives for (Artemis I), and meeting the objectives of the Artemis I program," said Jim Free, associate administrator for NASA's Exploration Systems Development Mission Directorate, during last week's news conference.

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Re: SLS Roll-out

#9 Post by Boac » Mon Jun 20, 2022 6:02 pm

Yet another 'valve' issue? Is this a repeat of the Shuttle 'lowest bidder' fiasco? I don't think I would want to ride it.

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Re: SLS Roll-out

#10 Post by Boac » Tue Jun 21, 2022 7:28 am

A Hydrogen leak developed in the quick disconnect arm and would have prevented the completion of the test except for the fact that the 'team' told the launch control computer to ignore the leak and the test completed 'satisfactorily'............

That's alright, then..............

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Re: SLS Roll-out

#11 Post by PHXPhlyer » Tue Jun 21, 2022 5:25 pm

Boac wrote:
Tue Jun 21, 2022 7:28 am
A Hydrogen leak developed in the quick disconnect arm and would have prevented the completion of the test except for the fact that the 'team' told the launch control computer to ignore the leak and the test completed 'satisfactorily'............

That's alright, then..............
Mure than just a Hydrogen leak.

Artemis moon rocket achieves milestones despite issues during critical prelaunch test


https://www.cnn.com/2022/06/20/world/na ... index.html

The Artemis I mega moon rocket has been fully fueled for the first time.

The fourth attempt of a final prelaunch test started on Saturday and the rocket tanks were filled on Monday.

The crucial test, known as the wet dress rehearsal, simulates every stage of launch without the rocket leaving the launchpad at Kennedy Space Center in Florida.

This process includes loading supercold propellant, going through a full countdown simulating launch, resetting the countdown clock and draining the rocket tanks.

The results of the wet dress rehearsal will determine when the uncrewed Artemis I will launch on a mission that goes beyond the moon and returns to Earth. This mission will kick off NASA’s Artemis program, which is expected to return humans to the moon and land the first woman and first person of color on the lunar surface by 2025.

Three previous attempts at the wet dress rehearsal in April were unsuccessful, concluding before the rocket could be fully loaded with propellant due to various leaks. These have since been corrected, NASA says.

The NASA team rolled the 322-foot-tall (98-meter-tall) Artemis I rocket stack, including the Space Launch System and Orion spacecraft, back to the launchpad at Kennedy Space Center in Florida on June 6.

Wet dress rehearsal steps
The wet dress rehearsal began at 5 p.m. ET Saturday with a “call to stations” – when all of the teams associated with the mission arrive at their consoles and report they’re ready for the test to begin and kick off a two-day countdown.

Preparations over the weekend set up the Artemis team to start loading propellant into the rocket’s core and upper stages Monday morning.

Tanking was on hold Monday morning because of an issue identified with the backup supply of gaseous nitrogen. The launch team replaced the valve causing the issue. In order to make sure the backup supply is functioning as expected, it was swapped in as the primary supply for the test.

The hold lifted at 9:28 a.m. ET. Liquid oxygen, cooled to minus 297 degrees Fahrenheit (minus 182 degrees Celsius), and liquid hydrogen were used to fill the core stage before moving on to the rocket’s upper stage. Venting was visible from the rocket throughout the process.

The core stage was mostly filled and the team was filling the upper stage when several issues occurred just after 2 p.m. ET.

The team discovered a hydrogen leak at a quick disconnect line for the core stage. Their first option did not work and they looked into options to seal the leak.

Something from the flare stack, where excess liquid hydrogen from the rocket is burned off with propane flames, caused a small grass fire burning toward a dirt road. The team monitored the grass fire and expected the fire to die out when it reached the dirt road.

The test exceeded a planned 30-minute hold, which was extended as engineers tried to work on solutions for the hydrogen leak.

The Artemis team decided to go through with one countdown, while masking the hydrogen leak issue, “in order to get further into the testing for today’s wet dress rehearsal,” according to a tweet from NASA’s Exploration Ground Systems.

The 10-minute countdown began at 7:28 p.m. ET.

Typically, there are two countdowns during the wet dress rehearsal. First, team members usually go through a countdown to 33 seconds before launch, then stop the cycle. The clock is reset, and then the countdown resumes again and runs until about nine seconds before a launch would occur.

Monday’s abbreviated countdown ended prematurely with 29 seconds left on the countdown clock. A flag from the SLS rocket’s computer triggered the cutoff, but the exact flag has not been shared. Prior to the countdown, the team said if the computers involved in the countdown sense the hydrogen leak, it might be akin to a check engine light that forces a premature stop to the countdown.

Once the countdown halted, the Artemis team worked on ensuring that the vehicle was safe.


Charlie Blackwell-Thompson, Artemis launch director for NASA’s Exploration Ground Systems Program, said it was “definitely a good day for us” after achieving multiple milestones outlined in the wet dress objectives, like fully tanking the rocket and getting through a countdown.

The next steps will be assessing all of the data collected from the test, including the issues, and laying out a plan to go forward, she said.

The previous wet dress rehearsal attempts have already completed many objectives to prepare the rocket for launch, Blackwell-Thompson said.

There is a long history behind the arduous testing of new systems before a launch, and the Artemis team faces similar experiences to those of the Apollo- and shuttle-era teams, including multiple test attempts and delays.
at Launch Pad 39B at NASA's Kennedy Space Center in Florida on March 23, 2022. The SLS and Orion atop the mobile launcher were transported to the pad on crawler-transporter 2 for a prelaunch test called a wet dress rehearsal. Artemis I will be the first integrated test of the SLS and Orion spacecraft. In later missions, NASA will land the first woman and the first person of color on the surface of the Moon, paving the way for a long-term lunar presence and serving as a steppingstone on the way to Mars.

The mission team is looking at possible launch windows for sending Artemis I on its journey to the moon in late summer: August 23 to August 29, September 2 to September 6 and beyond.

PP

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llondel
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Re: SLS Roll-out

#12 Post by llondel » Tue Jun 21, 2022 7:38 pm

The mission team is looking at possible launch windows for sending Artemis I on its journey to the moon in late summer: August 23 to August 29, September 2 to September 6 and beyond.
They need to avoid 10th September because the moon will be full on that day.

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Re: SLS Roll-out

#13 Post by Boac » Tue Jun 21, 2022 8:27 pm

It won't be a problem, though, will it? They are going in daytime.

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