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posted by janrinok on Wednesday June 22 2022, @10:54AM   Printer-friendly
from the for-some-values-of-'success' dept.

NASA finally succeeds with its Artemis 1 wet launch test:

NASA encountered a couple of issues while conducting the Artemis 1 "wet dress rehearsal," but it still checked off a major milestone by the time the test had ended. The agency was able to fully fuel all the Space Launch System's propellant tanks for the first time and was able to proceed to terminal launch countdown. [...]

This attempt wasn't flawless either: NASA had to put fueling on hold a couple of times since the rehearsal started on Saturday. Fueling was first put on hold on early Monday morning due to an issue with the rocket's backup supply of gaseous nitrogen. The team was able to repair the valve for the gaseous nitrogen line, however, and fueling recommenced a couple of hours later. As CNN notes, though, a few issues popped up just as the team was finishing up the fueling process on Monday afternoon. They discovered a hydrogen leak and had to find options to seal it after their first solution didn't work. Plus, the flare stack, which burns excess liquid hydrogen from the rocket, caused a small fire in the grassy area around the launch site.

In the end, the launch controllers came up with a plan to mask data associated with the leak so as not trigger a hold by the launch computer. That wouldn't fly in a real launch scenario, but they wanted to get as far into the countdown as possible to gather the data they need. They were successfully able to resume the 10-minute final launch countdown after an extended hold and got to T-29 seconds before they had to end the test completely. [...]

Regardless, they successfully performed several critical operations needed for launch during the test, including handing over control from the ground launch sequencer to the automated launch sequencer controlled by the rocket's flight software.

    Space Launch System Test Delayed for Weeks After Three Failed Attempts
    Artemis I Wet Dress Rehearsal Now Scheduled to Begin April 12
    NASA's Big Rocket Faces its Last Test Before Launching

Original Submission

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NASA’s Big Rocket Faces its Last Test Before Launching 14 comments

NASA's big rocket faces its last test before launching:

After two weeks of preparatory work on the launch pad at Kennedy Space Center, NASA is ready to put its large new rocket and its complex plumbing system to the test. This will be the final major rehearsal before the space agency declares that, after 11 long years and tens of billions of dollars in development costs, the Space Launch System is finally ready to fly.

The "wet dress rehearsal" is slated to begin at 5 pm ET (21:00 UTC) on Friday, when the launch control teams will arrive on console at the Launch Control Center. At that point, engineers and technicians will begin to power up the Orion spacecraft and the rocket itself. But the real action will not take place until Sunday.

At around 6 am ET, a team from NASA and the launch vehicle's contractors will enter a "launch day" countdown; shortly thereafter, they will start to fuel the rocket's core stage with liquid oxygen. The loading of liquid hydrogen will begin about an hour later. NASA has posted a tentative schedule with key milestones on its website.

After a series of holds, NASA plans to resume its countdown toward launch at 2:30 pm ET on Sunday and continue until about T-10 seconds, with the test ending before igniting the rocket's four main engines, which once powered NASA's space shuttle. If all goes well, the test will wrap up by around 5 pm on Sunday.

[...] So will all go well? During a call with reporters on Tuesday, senior NASA officials seemed fairly confident that the wet dress test would go off smoothly. However, they acknowledged that this is the first time the entire rocket and spacecraft will be handled and fueled in concert with its ground systems and the extensive software to manage it all. So yes, they acknowledged, things could go wrong.

About a week after the test is complete, NASA officials said they expect to be able to set a launch date for the Artemis 1 mission, which will fly an uncrewed Orion spacecraft around the Moon. Presently, this test flight will happen no earlier than June.

Original Submission

Artemis I Wet Dress Rehearsal Now Scheduled to Begin April 12 21 comments

NASA has been preparing for a wet dress rehearsal for the Artemis I rocket, but have hit several issues causing delays, the most recent being a faulty helium gas check valve. They have now announced that a modified wet dress rehearsal will start with a call to stations on April 12. This rehearsal proceeds through as an actual launch activity that scrubs at the T-10 second point. The modified test will focus on filling the core stage with cryogenic propellant, but with minimal propellant operations on the interim cryogenic propulsion stage (ICPS). Following the test, the rocket will be returned to the Vehicle Assembly Building to replace the helium check valve as well as to assess the launch procedures.

NASA is streaming live video of the rocket and spacecraft on the Kennedy Newsroom YouTube channel.

Original Submission

Space Launch System Test Delayed for Weeks After Three Failed Attempts 18 comments

NASA to roll back its mega rocket after failing to complete countdown test

After three attempts to complete a critical fueling test of the Space Launch System rocket, NASA has decided to take a break.

On Saturday night the space agency announced plans to roll the large SLS rocket from the launch pad at Kennedy Space Center to the Vehicle Assembly Building in the coming days. This marks a notable step back for the program, which has tried since April 1 to complete a "wet dress rehearsal" test, during which the rocket is fueled and brought to within 10 seconds of launch.

The decision comes after three tries during the last two weeks. Each fueling attempt was scuttled by one or more technical issues with the rocket, its mobile launch tower, or ground systems that supply propellants and gases. During the most recent attempt, on Thursday April 14, NASA succeeded in loading 49 percent of the core-stage liquid oxygen fuel tank and 5 percent of the liquid hydrogen tank.

While this represents progress, it did not include the most dynamic portion of the test, during which the rocket is fully fueled and pressurized; and it, the ground systems, and computer systems are put into a terminal countdown when every variable is closely monitored. NASA had hoped to complete this wet dress rehearsal test to work out the kinks in the complicated launch system so that, when the rocket is rolled out later this year for its actual launch, the countdown will proceed fairly smoothly.

Also at Spaceflight Now.

Previously: Artemis I Wet Dress Rehearsal Now Scheduled to Begin April 12

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  • (Score: 0) by Anonymous Coward on Wednesday June 22 2022, @12:35PM (5 children)

    by Anonymous Coward on Wednesday June 22 2022, @12:35PM (#1255332)

    SpaceX runs with failure is not an option is sub-optimal as long as you learn and nobody get's hurt.

    Why isn't this be an example of Boeing actually testing and sorting things out before launch?

    They have a LOT of pressure to get it right when they actually press the launch button. Any bugs they find before this is a good thing as long as they learn and nobody gets hurt.

    (It is kind of fun to hold B up to the standards of X, though ;-)

    • (Score: 1, Insightful) by Anonymous Coward on Wednesday June 22 2022, @02:11PM

      by Anonymous Coward on Wednesday June 22 2022, @02:11PM (#1255351)

      There's not a thing wrong with finding problems now rather than later, but the problem is that they didn't finish the test. Will they do it again to exercise the last 30 seconds? If this were a SpaceX rocket, I'm sure NASA would require them to re-test. But since it's SLS, they'll probably declare it a success, and hope that there aren't any other, undetected problems in the last 30 seconds of the launch sequence.

    • (Score: 4, Insightful) by Freeman on Wednesday June 22 2022, @03:10PM (3 children)

      by Freeman (732) on Wednesday June 22 2022, @03:10PM (#1255369) Journal

      The big problem is that's not their model.

      SpaceX is on an iterative cycle, continuously improving and testing. When things go boom, they already have the next rocket in production and can tweak it, to fix the problem. SLS is on a monolithic cycle, if it goes boom, expect a few more billion being needed to make a #2.

      Joshua 1:9 "Be strong and of a good courage; be not afraid, neither be thou dismayed: for the Lord thy God is with thee"
      • (Score: 1, Insightful) by Anonymous Coward on Wednesday June 22 2022, @04:38PM (2 children)

        by Anonymous Coward on Wednesday June 22 2022, @04:38PM (#1255391)

        "The big problem is that's not their model."

        True, but neither model (analyse to death and expect success or just built it) works. One needs a dash of humility to use both models in concert.
        This story seems to be about something failing in incremental testing probably after analysis to death says it should work.

        If they take the lesson as they should have done more analysis, then they still don't get it, and yes, they have a big problem.
        If they take the lesson as analysis doesn't eliminate the need for testing and failing a test can be ok, then maybe their problem is not a big one.

        • (Score: 1, Informative) by Anonymous Coward on Wednesday June 22 2022, @05:01PM (1 child)

          by Anonymous Coward on Wednesday June 22 2022, @05:01PM (#1255398)

          Management always wants to cut ground testing because it can save a lot of money and schedule, so they are very tempted to sign off with validation by analysis.

          • (Score: 2, Interesting) by Anonymous Coward on Thursday June 23 2022, @04:37AM

            by Anonymous Coward on Thursday June 23 2022, @04:37AM (#1255524)

            Prototyping is both cheaper and much faster than the deep systems analysis NASA typically does. Such analysis is necessary for deep space missions where field testing simply isn't possible, but due to cost plus contracts with Congressionally enforced lack of accountability it gets used in absence of prototyping precisely because it is more expensive and takes longer, creating many more billable hours.

            You are correct that a combination approach is optimal, which is how NASA used to do it and SpaceX does it now.