Updates SLS Updates

[GLS]

https://twitter.com/i/web/status/1311844275395735555

?‍ ?‍

 

[Urwumpe]

Wait a minute - not even HIL testing of the whole avionics boiler plate?

They got to be joking. ?‍

 

[n72.75]

Wait what!?

 

[Sbb1413]

Whisky Tango Foxtrot! The early Artemis missions will have no avionics like Yuri Gagarin!?

 

[Gargantua2024]

NASA's acting kinda sus

 

[DaveS]

Whisky Tango Foxtrot! The early Artemis missions will have no avionics like Yuri Gagarin!?

They'll have a full suite of avionics, it just that that the avionics will not have undergone a full test set up in an integrated fashion. They'll be fully tested and certified separately but they might opt forgo the integration testing in the lab and just do it with the actual on-vehicle avionics with the entire assembled SLS/Orion in the VAB. This would mimic very closely what each shuttle mission was put through prior to rollout after the mating of the orbiter vehicle. It was called the Shuttle Interface Test (S0008) and was the first time each newly assembled stack had been powered up. The stack had to pass S0008 before it was cleared for rollout to the pad. The test usually lasted several days and went on in parallel with other close-out work and pre-rollout preparations.

 

[Urwumpe]

They'll have a full suite of avionics, it just that that the avionics will not have undergone a full test set up in an integrated fashion. They'll be fully tested and certified separately but they might opt forgo the integration testing in the lab and just do it with the actual on-vehicle avionics with the entire assembled SLS/Orion in the VAB. This would mimic very closely what each shuttle mission was put through prior to rollout after the mating of the orbiter vehicle. It was called the Shuttle Interface Test (S0008) and was the first time each newly assembled stack had been powered up. The stack had to pass S0008 before it was cleared for rollout to the pad. The test usually lasted several days and went on in parallel with other close-out work and pre-rollout preparations.

Well, the Shuttle also had the SAIL from the start on, which was used for integration testing.

Shuttle Avionics Integration Laboratory - Wikipedia

en.wikipedia.org

 

[DaveS]

Well, the Shuttle also had the SAIL from the start on, which was used for integration testing.

Shuttle Avionics Integration Laboratory - Wikipedia

en.wikipedia.org

The SAIL was more for orbiter avionics integration, than full stack avionics integration. That's what's missing for SLS/Orion and what Boeing with their CST-100 Starliner missed. All the problems stemmed from a lack of full stack integration testing. The Atlas FSW team changed something on their end that wasn't compatible with the CST-100 FSW. This is something more full stack integrated testing would have caught.

 

[Urwumpe]

This is something more full stack integrated testing would have caught.

Yes, but that requires a lot of effort, to perform such a test, its only slightly cheaper than launching the whole thing.

 

[DaveS]

Yes, but that requires a lot of effort, to perform such a test, its only slightly cheaper than launching the whole thing.

You could schedule a full up countdown test once the spacecraft has been mated. This is what ULA/Boeing did for CST-100 OFT-1 pad flow, although what was missed was performing a simulated plus count to verify that the LV and payload were really talking correctly. This is something new to the ULA launch team, an active payload through the count and ascent. All the other payloads that are launched are passive through the Terminal Count and ascent and only goes active following spacecraft separation. This isn't something that's lost on the EM-1 processing team, once Orion has been mated to the ICPS in the VAB, the entire stack will be powered up for a long series of tests. Even Columbia during the VAB flow for STS-1 spent 35 days undergoing several tests and checkouts before rolling out to 39A where she spent another 105 days.

 

[Urwumpe]

Well, as you can see too often, it is a necessary test, but it is a very expensive test if you need to repeat it more than once in a blue moon.

That is why HIL testing and contract/interface testing is mandatory.

 

[Sbb1413]

The SAIL was more for orbiter avionics integration, than full stack avionics integration. That's what's missing for SLS/Orion and what Boeing with their CST-100 Starliner missed. All the problems stemmed from a lack of full stack integration testing. The Atlas FSW team changed something on their end that wasn't compatible with the CST-100 FSW. This is something more full stack integrated testing would have caught.

You don't have to use CST-100 to mean Starliner. Just call it "Boeing Starliner".

 

[Notebook]

SLS: Crucial test for Nasa's 'mega-rocket' - BBC News

 

[cannon_gray]

How could they implement Artemis mission by 2024 which requires lots of devices, modules, spacecrafts and whatever else be built while they have been developing SLS since 2011 and still have only concept and nothing ready to test? It would be much better to use Starship launch vehicle which is almost ready by the way..

 

[4throck]

"developing SLS since 2011 and still have only concept and nothing ready to test?"
It's complete and undergoing final tests....

"Starship... almost ready" ?
Still years from a complete Starship vehicle.
There's no launchpad, it's unclear where it will land, no idea about crew escape or safety.

I'm a SpaceX enthusiast, but let's be realistic. It might fly in 1 year for cargo (Starlink satellites).
But a human rated variant will take a many extra years.
It's not only the rocket, it's also the ground infrastructure for refueling. Starship needs dozens of tanker flights to top it's fuel before going beyond earth.
And I bet NASA will ask about a crew escape system...

 

[Sbb1413]

Yeah, we need a human-rated launch vehicle that can go beyond Earth orbit first before thinking about a human-rated reusable launch vehicle that can go beyond Earth orbit. This is why I need both the orange can and the stainless steel can.

There's no launchpad, it's unclear where it will land, no idea about crew escape or safety.

And I bet NASA will ask about a crew escape system...

SpaceX will use Boca Chica for both the launch site and the landing zone. And SpaceX is overengineering the whole vehicle to suppress any launch abort system, while increasing the success rate of the vehicle. When asking about implementing an abort system for Starship, the father of X Æ A-XII said, "The best part is no part."

 

[Gargantua2024]

Yeah, we need a human-rated launch vehicle that can go beyond Earth orbit first before thinking about a human-rated reusable launch vehicle that can go beyond Earth orbit

I never thought that this is one great logical defense for the SLS. Thinking what if there's people flying on SN8 during the hard-flippin maneuver to landing scares me to this day. Until Starship nailed its flight profile flawlessly many times, NASA has to rely on the SLS to send astronauts back to the Moon, which is getting clearer by the day as its final test of the Green Run is days away from happening soon

 

[Sbb1413]

In the case of lunar lander, if Starship isn't ready, then NASA may rely on Dynetics or the National Team to send astronauts back to the Moon. Both of them are reusable in some extent.

 

[4throck]

SpaceX will use Boca Chica for both the launch site and the landing zone. And SpaceX is overengineering the whole vehicle to suppress any launch abort system, while increasing the success rate of the vehicle. When asking about implementing an abort system for Starship, the father of X Æ A-XII said, "The best part is no part."

They can't launch to orbit regularly from Boca Chica. Remember that people live there, and they need to be evacuated for each launch....
So things will eventually move to a better location, and that will take some time.

If NASA requires an escape system in order to human rate the rocket, Elon must put it there.
On Crew Dragon NASA demanded a water landing and parachute changes, even though Elon wanted a land landing and the original chute was safe

These are not problems, just things that will take extra time to get solved (add 1 to 2 years).
So being very optimistic, I'd say the first cargo Starship flies in 2022, with the possibility of a human rated variant in 2024.
But this for LEO. Remember that beyond that you need refueling, and that hasn't been tested yet.

 

[barrygolden]

Just a little insight Space X is looking at a sea launch platform for Starship. Looks like Boca Chica could be the construction site with Elon moving out of California. I thought I saw where he past Bezos as the worlds richest man