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[IronRain]

Boeing plans changes to SLS upper stages

BREMEN, Germany — With NASA’s decision to continue using an interim upper stage for additional flights of the Space Launch System, Boeing is working on changes to both that stage and a more powerful upper stage.

In an Oct. 3 call with reporters, John Shannon, vice president and program manager for the Space Launch System at Boeing, said NASA has asked Boeing to look at changes to the Exploration Upper Stage (EUS) to improve its performance.

Those changes were prompted by the decision NASA made earlier this year to delay the introduction of the EUS. That stage was originally planned to enter use with the second SLS mission, Exploration Mission (EM) 2. Instead, the first flight of what’s known as the Block 1B configuration of SLS has been delayed to the fourth SLS launch, likely no earlier than 2024.

“That has put a slow down on the Exploration Upper Stage work,” he said. “We were rapidly approaching the critical design review.”

[...]

I've read on the interwebs that employees officially were told that it's a 100 days pause, but unofficially the project has been paused for at least a year.

Source:
- https://spacenews.com/boeing-plans-changes-to-sls-upper-stages/

 

[Urwumpe]

And as you can expect, more delays and cost overruns:

https://oig.nasa.gov/docs/IG-19-001.pdf

 

[DaveS]

Latest RS-25 hotfire test Stennis Space Center just aborted seconds after ignition as fire erupted from the powerhead of the RS-25. This is the first RS-25/SSME hotfire test to be aborted due to an engine hardware failure in decades.

https://www.dropbox.com/s/vfapbq1xq78zu7k/RS25_POWERHEAD_FIRE.jpg?dl=0

---------- Post added at 10:39 PM ---------- Previous post was at 10:33 PM ----------

Last time an actual launch was aborted due to an SSME component failure was STS-68 on August 18 1994 at T-1.9 seconds when the discharge temperature on MPS SSME Main Engine #3 High Pressure Oxidizer Turbopump (HPOT) exceeded its redline value.

---------- Post added at 10:39 PM ---------- Previous post was at 10:39 PM ----------

 

[Urwumpe]

Was it really a SSME failure or rather related to the test stand? I can't see the origin of the fire, but it seems to be near the turbopump on the opposite side.

 

[DaveS]

Was it really a SSME failure or rather related to the test stand? I can't see the origin of the fire, but it seems to be near the turbopump on the opposite side.

This is the approximate location of the fire based on what identifiable components were seen in the camera view:
https://www.dropbox.com/s/tsy74sff4gld9qt/RS25_HPFTP_FIRE_LOCATION.jpg?dl=0

 

[GLS]

Wow, it took them how many seconds to shut the engine down? In the beginning they had people looking at the cameras and they would shut it down at the first sign of trouble.

Anyway, that could very well be fuel preburner trouble: the location matches and also the plume at shutdown seems to have bits of something.... probably engine.

 

[DaveS]

Based on this screenshot taken during the shutdown phase, it looks the fire was coming from a facility pipe and not the engine: https://www.dropbox.com/s/an6stuhiprncarb/RS25_FACILITY_FLAMES.jpg?dl=0

 

[Kyle]

Looked like a GSE failure unrelated to the actual engine itself.

 

[Majid]

This may be a very stupid question but: Are the RS-25 engines being used/tested completely rebuilt or were they used in the Shuttle at some point?

 

[Urwumpe]

This may be a very stupid question but: Are the RS-25 engines being used/tested completely rebuilt or were they used in the Shuttle at some point?

Think of them as completely rebuild. While 99% of the parts are Shuttle heritage, there are some important changes to them.