NASA to have another go at firing Space Launch System engines because just over a minute of data won't cut it Hopes of a launch of NASA's Space Launch System (SLS) in 2021 have been dealt a further blow by an admission that a second Green Run hot fire test is required for the SLS core stage. The Boeing-led core stage for NASA's monster Moon rocket arrived at the Stennis Space Center, Mississippi, over a year ago and was mounted in the …
I wish them well but I don't have high hopes.
In contrast to the first moon landing, SLS up till now has relied on research and design whereas Apollo relied on building, testing, and flying bigger and bigger rockets. After 11 years Apollo made it to the moon while after 10 years the SLS has yet to launch.
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.
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.
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
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.
I have good news for you there!
Aerojet Rocketdyne got a $1.16x10⁹ contract to upgrade the RS-25 design for expendable operation and separate contract to build new 18 engines. After the first 4 SLS launches with the existing engines you can watch the remaining 4 launches secure in the knowledge that 4x $200,000,000 engines were designed to be thrown in the sea. (This does assume that you are sufficiently young and healthy to live long enough to see SLS actually launch.)
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------.
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."
"the agency was quick to point out that the scenario would not have happened on the launch pad"
It wouldn't have happened in the sense that the safety wouldn't have tripped and everything would have been fine, or it wouldn't have happened in the sense that the safety wouldn't have tripped and everything would have exploded? The whole problem with the test not finishing is that there's not enough information to know what might have happened if it hadn't stopped. Maybe the limit was just too conservative, but maybe things would have got a lot worse if the test continued. It's good that they're running another test, but utter madness that they even considered not doing so.
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