NASA to have another go at firing Space Launch System engines because just over a minute of data won't cut it
- Reference: 1612187767
- News link: https://www.theregister.co.uk/2021/02/01/nasa_sls_hotfire_2/
- Source link:
The Boeing-led core stage for NASA's monster Moon rocket arrived at the Stennis Space Center, Mississippi, [2]over a year ago and was mounted in the B-2 test stand for a succession of check-outs known as the Green Run. These culminated in a firing of all four Shuttle-derived RS-25 engines in order to simulate a launch.
[3]
[4]Things did not go well . "Intentionally conservative" test parameters resulted in a premature pfffft and the run only lasted for 67.2 seconds. That's quite some way from an actual launch, although the agency was quick to point out that the scenario would not have happened on the launch pad. The abort left the hardware "in excellent condition."
At the time, engineers were set the unenviable task of working out if enough data had been collected to justify shipping the stage to Kennedy Space Center. That assessment has been done, and the result was... nope. At least four minutes of data was needed in order to verify the stage was ready for flight and barely a minute simply wasn't going to cut it.
[5]
Therefore engineers are to press ahead with a second run, and once again aim for the eight minutes needed to simulate a launch. Those pesky parameters will be tweaked, and the engines refurbished. The faulty electrical harness that triggered the Major Component Failure instrumentation notification on Engine 4 has already been repaired.
The problem for mission managers is one of schedule. Once the second hotfire is performed, which could be "as early as the fourth week in February" according to the agency, it will take a further month to refurbish the stage and engines once more before shipping it to Kennedy Space Center by barge. It will then be mated with the other components of the system ahead of an Artemis launch "later this year."
[6]
Based on performance to date, it is difficult to see how a launch in 2021 is possible even if managers find a way of performing tasks in parallel to make up the time lost by the Green Run problem. A failure to launch the first (uncrewed) test flight in 2021 will put further pressure on the already slim chance of a landing in 2024. ®
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[1] https://blogs.nasa.gov/artemis/2021/01/29/green-run-update-nasa-proceeds-with-plans-for-second-hot-fire-test/
[2] https://www.nasa.gov/feature/nasa-artemis-program-and-stennis-space-center-set-the-stage-for-testing-in-2020
[3] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_science/front&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=2&c=2YBgzpDtwzm3TyEww9v-5SAAAAMU&t=ct%3Dns%26unitnum%3D2%26raptor%3Dcondor%26pos%3Dtop%26test%3D0
[4] https://www.theregister.com/2021/01/19/sls_initial_data/
[5] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_science/front&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=3&c=33YBgzpDtwzm3TyEww9v-5SAAAAMU&t=ct%3Dns%26unitnum%3D3%26raptor%3Deagle%26pos%3Dmid%26test%3D0
[6] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_science/front&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=4&c=44YBgzpDtwzm3TyEww9v-5SAAAAMU&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%26test%3D0
[7] https://whitepapers.theregister.com/
Schedules
I would have though that it was more important to confirm that it works as expected rather than rushing to meet a deadline set some time ago. The thing with rockets is that there is a fine line between success and failure but failure is generally catastrophic for the vehicle and any payload, man or machine......
I don't see how NASA can survive another incident like the Space Shuttle Challenger disaster.
Re: Schedules
Precisely. Safety should come before meeting an arbitrary deadline set by Trump. Which I'm assuming they can safely ignore now. They shouldn't rush it, people's lives are more important than glory.
Re: Schedules
"people's lives are more important than glory"
You've never been in politics, have you!
Re: Schedules
There's another problem in that the tankage is only certified for something like nine fuelling cycles. They've already used up two, the repeat will use a third, and they'll need at least one when it gets to the Cape to prove all the pad facilities work. A couple of last minute problems during launch attempts and they're looking at the possibility of having to take it all apart and use a new core stage.
bad design
the SLS is a bad design from the start. The good option was to re-use the Space-Shuttle components as they were, only removing the wings to save weight, and they had a ready to go system with minimal redesign. The could have put the payload on top of the main (reinforced) tank, à-là Ariane-V, and ready they were.
But no, instead of this, the redesigned the entire rocket, bigger, badder, with bigger boosters, everything new.
They could also have gone for smaller rockets and assemble the moon-lander from several launches at the ISS. But no, they wanted a new Saturn V ... except that Werner von Braun is not around any-more to save their a***es
Re: bad design
The shuttle main tank was never the way to go - it had no mounts for engines, no flight computers, no interstage, ...
Adding an extra block to the SRB's was "easy" and they have already been tested for flight.
I've never quite got to grips with throwing four shuttle main engines in the sea each launch - they are rated for 16 flights, so that's one serious waste of money / engineering.
Reproductivity
It will then be mated with the other components of the system...
I'm not sure any more mating is required - it's already been thoroughly f**ked by the beancounters and mismanagement.
How are the mighty fallen
In the 60s Boeing built the Saturn V first stage and pretty much simultaneously got the 747 done whilst also working on the (politically-important) SST.
Fast forward 50 years and they **** up the 737 Max and the Artemis core stage is looking pretty dubious.
Bean counters--.
Elon, meanwhile------.
Can only load the stage with propellant 9 times
https://spacenews.com/nasa-to-perform-second-sls-green-run-test/
"the core stage was designed to be loaded with cryogenic propellants, liquid hydrogen and liquid oxygen, only nine times. With two of those fuelings already used for the hotfire test and an earlier wet dress rehearsal, an additional static-fire test would cut into the margin used for tests at the Kennedy Space Center and launch attempts."
"will put further pressure on the already slim chance of a landing in 2024"
I think we can scrap that already, unless some miracle happens.
Silly people, SLS isn't supposed to fly but to provide jobs in Alabama.
Yet again, they are being owned by SpaceX - but thankfully SpaceX are lad that isn't in a literal sense.....
Boeing
Another day another problem involving Boeing - seems like they can't get anything right these days.