Author Topic: SLS General Discussion Thread 2  (Read 225458 times)

Offline muomega0

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Re: SLS General Discussion Thread 2
« Reply #280 on: 01/29/2016 09:34 PM »
1 SSPF for cargo processing and preps
It can't  handle encapsulated or hazardous payloads.  Without hazardous processing facility, SLS is limited to Orion.
Wasn't SSPF in the 2016 plus up?

Offline Coastal Ron

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Re: SLS General Discussion Thread 2
« Reply #281 on: 01/29/2016 09:38 PM »
I'm more optimistic than that. I think once past its teething pains SLS could be expected to fly once every 18 months with Orion, and once every 24 months without Orion. If I'm summing correctly, that adds up to an overall flight rate of once every 10.3 months. I would be mildly astonished if with all said and done Boeing and AJR couldn't produce the requisite hardware at that pace.

My background is in manufacturing operations, and I have no doubt that all suppliers in the SLS food chain would be able to meet whatever rate is needed.

So don't worry about how many SLS can be produced, instead focus on how many SLS need to be produced - focus on the payloads and missions that can only be lifted by the SLS.  Because it's never been about whether NASA can build an HLV, but whether NASA needs an HLV.
If we don't continuously lower the cost to access space, how are we ever going to afford to expand humanity out into space?

Online Robotbeat

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Re: SLS General Discussion Thread 2
« Reply #282 on: 01/30/2016 12:18 AM »
There's enough money in the world to fly SLS at a much higher flight rate than it is designed for right now (0.5 to 2 per year). And I'm sure the people pushing hard for SLS are hoping on hope that they will get China to go to Mars or something and get that money (from the US Congress, not China... not directly, at least). Which isn't going to happen any time soon.

Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

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Offline Hotblack Desiato

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Re: SLS General Discussion Thread 2
« Reply #283 on: 01/30/2016 12:30 AM »
Yes, nobody knows if the next or next but one president suddenly has an inspiration of putting a man onto mars before the end of the decade (whichever that is). And then it could be quite handy to have a HLV available. Because we currently see how long it takes NASA to develop one.
« Last Edit: 01/30/2016 12:31 AM by Hotblack Desiato »

Online Robotbeat

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Re: SLS General Discussion Thread 2
« Reply #284 on: 01/30/2016 12:33 AM »
Yes, nobody knows if the next or next but one president suddenly has an inspiration of putting a man onto mars before the end of the decade (whichever that is). And then it could be quite handy to have a HLV available. Because we currently see how long it takes NASA to develop one.
Right. They essentially are building SLS on the slim hope of a new space race, which I think they'd even acknowledge is a fairly slim possibility.
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline mike robel

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Re: SLS General Discussion Thread 2
« Reply #285 on: 01/30/2016 01:32 AM »
As far as KSC goes; we could fly an SLS every 6 months (our requirement) with what assets we now have in work:
1 VAB High Bay
The VAB Transfer Isle for SLS core preps
1 VAB Low Bay Cell for EUS preps
1 ML
1 Crawler
1 Launch Pad
1 SRB aft skirt processing facility
1 SRB segment processing facility
1 Orion assembly and check out facility
1 Orion fueling and processing facility
1 Firing Room
1 SSPF for cargo processing and preps


Thanks for this Scotty.  I appreciate the correction to my thinking.


Offline Scotty

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Re: SLS General Discussion Thread 2
« Reply #286 on: 01/30/2016 03:31 PM »

1 SSPF for cargo processing and preps


It can't  handle encapsulated or hazardous payloads.  Without hazardous processing facility, SLS is limited to Orion.

I said "Cargo Processing and Preps", I said nothing about payload fueling or encapsulation.
There are the AstroTech facilities for that.
They also could do payload encapsulation in the old Shuttle Payload Canister Facility.
But, there is no rush to modify facilities to do so, as there are no SLS Cargo Payloads on the books.
Lots of "maybe" and "might happen", but nothing hard on the books at this time.

Offline OV135

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Re: SLS General Discussion Thread 2
« Reply #287 on: 02/06/2016 10:39 PM »
I've not been here in a while. I saw the new SLS images and wonder why they changed the core stage color from that deja vu of Saturn V to the shuttle ET foam covered current look?

Offline Rocket Science

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Re: SLS General Discussion Thread 2
« Reply #288 on: 02/06/2016 10:50 PM »
I've not been here in a while. I saw the new SLS images and wonder why they changed the core stage color from that deja vu of Saturn V to the shuttle ET foam covered current look?
Save weight... ;)
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Offline rocx

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Re: SLS General Discussion Thread 2
« Reply #289 on: 02/08/2016 10:41 AM »
I've not been here in a while. I saw the new SLS images and wonder why they changed the core stage color from that deja vu of Saturn V to the shuttle ET foam covered current look?
The theory I've read most around here is that there never was a serious intention to paint the core stage white, but that it was shown that way in promotion materials to set it apart from the cancelled Ares V.
Any day with a rocket landing is a fantastic day.

Offline oldAtlas_Eguy

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Re: SLS General Discussion Thread 2
« Reply #290 on: 02/12/2016 02:29 PM »
Hmmm.

http://forum.nasaspaceflight.com/index.php?topic=31740.msg1490778#msg1490778

Using a simulation object with a ? as to its authentic size and placement of fittings as a fit check device of another set of equipment for an as yet created piece of hardware subject to changes (the SLS core) is not what I consider a good use of funds other than it could reduce the more obvious problems but none of the subtle ones. It is what you do if you are running behind schedule and you are trying to make up some time.

Offline Endeavour_01

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Re: SLS General Discussion Thread 2
« Reply #291 on: 02/13/2016 03:06 AM »

Using a simulation object with a ? as to its authentic size and placement of fittings as a fit check device of another set of equipment for an as yet created piece of hardware subject to changes (the SLS core) is not what I consider a good use of funds other than it could reduce the more obvious problems but none of the subtle ones. It is what you do if you are running behind schedule and you are trying to make up some time.

The SLS core design is basically locked in now. Why would it change?
I cheer for both NASA and commercial space. For SLS, Orion, Falcon 9, Falcon Heavy, Dragon, Starliner, Cygnus and all the rest!
I was blessed to see the launch of Space Shuttle Endeavour on STS-99. The launch was beyond amazing. My 8-year old mind was blown. I remember the noise and seeing the exhaust pour out of the shuttle as it lifted off. I remember staring and watching it soar while it was visible in the clear blue sky. It was one of the greatest moments of my life and I will never forget it.

Offline the_other_Doug

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Re: SLS General Discussion Thread 2
« Reply #292 on: 02/13/2016 01:22 PM »

Using a simulation object with a ? as to its authentic size and placement of fittings as a fit check device of another set of equipment for an as yet created piece of hardware subject to changes (the SLS core) is not what I consider a good use of funds other than it could reduce the more obvious problems but none of the subtle ones. It is what you do if you are running behind schedule and you are trying to make up some time.

The SLS core design is basically locked in now. Why would it change?

There are always numerous, if relatively minor, alterations that occur to any design when metal starts being bent.  Even going from one block version of a vehicle to the next block version generally introduces numerous minor alterations.

That said, it's not like this is unprecedented in NASA rocket programs.  Recall that AS-500F was a full-scale mockup of the Saturn V vehicle, with all of the various connectors, plumbing leads, etc. that the real vehicle would have.  It allowed for the hands-on verification of the pad systems as well as electrical connectivity tests between the GSE and the dummy vehicle.  I don't believe that was wasted money.  However, even with all of those fit checks and procedures training that occurred on AS-500F, it still took three weeks to get through a four-day CDDT on the first actual flight vehicle, AS-501.  So, even with a dummy vehicle, nowhere near all of the learning curve was climbed working with the dummy vehicle.

Similarly, the shuttle Enterprise (an actual flight-configured vehicle in terms of its plumbing and electrical connections) was used for similar pad check-out purposes, with a dummy ET and dummy SRBs, after the A&LT program wound down.  And while that exercise was useful, there was still a lot of learning curve to climb when Columbia finally took its place on the pad to ready for flight.

I guess my point is that dummy vehicles (mockups) have been a part of NASA development for half a century or more.  And that such mockups are actually very useful, even after the design is pretty well frozen, to illustrate small changes still needed to the design (normally to interface positioning).  But they have never been the be-all and end-all of figuring out how everything will fit and work together, both on the pad and in flight.  So, the mockups aren't a waste of time or money, but by the same token they are not, and are never intended to be, completely identical to the real vehicles they are modeled on.

And the mockups are only useful after the final design has been pretty well frozen, but before major flight hardware has been built, so you don't find that, despite the way the specs have been reviewed, the main oxygen inlet fixture is somehow three inches lower and slightly to the right of where the main pad oxygen inlet plumbing has been positioned to connect to it (as a made-up example).  If the fix requires that the oxygen inlet on the rocket needs to be three inches higher up, then that change can be made on the as-yet-unbuilt flight hardware.  It's an awful lot more difficult to react to such situations if you wait until you have your flight hardware all built and find that you need to go back and scrap half of your stages because the inlet connections are all in a bad place.  Your only recourse at that point, really, is to kludge up the fittings in the pad hardware; enough of that and you have a bad, error-prone situation with your launch support systems.

There will always be a final learning curve to climb once you begin to fit together the actual flight stages and connect them to the pad hardware and GSE.  It would be an awfully lot higher curve to climb had they not gone through the mockup exercises, though...
-Doug  (With my shield, not yet upon it)

Offline oldAtlas_Eguy

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Re: SLS General Discussion Thread 2
« Reply #293 on: 02/13/2016 07:19 PM »
OK so these simulators are SOP for NASA and would be a normal part of any proposal and schedule for a NASA directed development.

Thanks for the info. Like I said it is useful for the obvious and as you mentioned it is highly useful in discovering when a procedure is in error. Procedures are less sensitive to minor design changes but very sensitive to the order of tasks. many order of tasks problems are not evident until you try to execute the procedures.

Offline Hog

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Re: SLS General Discussion Thread 2
« Reply #294 on: 03/02/2016 05:05 PM »
I just wanted to put some perspective on the entire SLS program.

We are 18 months from the planned cryo tanking test, and 20 months from the "Green Run Hotfire" test of the entire EM-1 Core Stage on the B-2 test stand at Stennis Space Center.

Image #1-Shows a Saturn S1-C 1st stage being hoisted into the test stand at Stennis SC
Image #2-Shows a S1-C hotfire test in 1967 at Stennis
Image #3-Shows a Saturn-V S1-C 1st stage leaving Stennis bound for KSC for stacking and launching.  Just imagine in early 2018, the EM-1 core stage will be making a similar voyage on the Pegasus barge.
Image #4-Shows a SLS core stage installed in the B-2 test stand for the hotfiring of 4 RS-25 engines

We are about to enter the 2nd quarter of 2016. Projects SLS and Orion are all coming together.  I can hardly wait to see, hear and FEEL 4 RS-25s light off followed shortly thereafter by 2 of the largest rocket engines in the world.  This is really happening, and launch day is rapidly approaching. 

Good work, and good luck to all those involved!


(of course all scheduling is subject to change)
Paul

Online Robotbeat

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Re: SLS General Discussion Thread 2
« Reply #295 on: 03/03/2016 02:51 AM »
...as much as I point out SLS is a complete waste of money, I /will/ still be trying to attend the first launch because it will be quite spectacular. :)
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Offline RocketGoBoom

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Re: SLS General Discussion Thread 2
« Reply #296 on: 03/04/2016 10:01 PM »
The SLS/Orion mission to visit the asteroid in orbit around the moon is looking like it is going to be delayed and possibly cancelled.

It is already being delayed to "study".

http://spacenews.com/nasa-slips-schedule-of-asteroid-redirect-mission/

Offline rayleighscatter

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Re: SLS General Discussion Thread 2
« Reply #297 on: 03/10/2016 08:19 PM »
Quote
On March 4, crew members ready a 900-pound steel beam to "top out" Test Stand 4697, which is under construction to test the Space Launch System liquid oxygen tank at NASA's Marshall Space Flight Center in Huntsville, Alabama. "Topping out" is a builders' rite traditionally held when the last beam is placed on top of a structure during its construction. The 85-foot-tall test stand will use hydraulic cylinders to subject the liquid oxygen tank and hardware of the massive SLS core stage to the same loads and stresses it will endure during a launch. The tests also will verify the models already in place that predict the amount of loads the core stage can withstand during launch and ascent. Prime contractor Brasfield & Gorrie of Birmingham, Alabama, and several of its subcontractors are constructing Test Stand 4697 and Test Stand 4693, which will have a twin-tower configuration and conduct similar structural tests on the SLS core stage's liquid hydrogen tank. Both stands are scheduled to be completed later this year. SLS will be the world's most powerful rocket and carry astronauts in NASA's Orion spacecraft on deep-space missions, including the journey to Mars.

Offline daveklingler

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Re: SLS General Discussion Thread 2
« Reply #298 on: 03/11/2016 08:35 PM »

Using a simulation object with a ? as to its authentic size and placement of fittings as a fit check device of another set of equipment for an as yet created piece of hardware subject to changes (the SLS core) is not what I consider a good use of funds other than it could reduce the more obvious problems but none of the subtle ones. It is what you do if you are running behind schedule and you are trying to make up some time.

The SLS core design is basically locked in now. Why would it change?

Has anyone here examined the possibility of an SLS first stage powered by AR-1 or BE-4 engines?  :)

Switching wouldn't change the timeframe that much, and it would drop the first stage cost by, oh...$200-250M, at a WAG.

Offline The Amazing Catstronaut

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Re: SLS General Discussion Thread 2
« Reply #299 on: 03/11/2016 09:55 PM »

Switching wouldn't change the timeframe that much...

Sure would - the first stage engines are one of the most pivotal, complex elements of the whole LV. You switch those out and you have to change the whole design, especially when you're talking different fuel types. We're talking about a rocket that'd be as different as SLS is from Aries V. There's a reason why Vulcan is massively different to merely a "re-engined Atlas V" as some community elements conceived it would be. Structure, tanking, tolerances, thermodynamics, stresses, aerodynamics, everything changes, mass, acceleration on ascent,  staging time, everything changes, everything must be recalculated, resimulated, reengineered, retested. You'd end up spending way more money than you'd save in infrastructure changes alone.

If SLS was re-engined, it'd die.

Boosters are a little bit different, but still a major element.
« Last Edit: 03/11/2016 10:00 PM by The Amazing Catstronaut »
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