Author Topic: SLS General Discussion Thread 2  (Read 223604 times)

Offline Robotbeat

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Re: SLS General Discussion Thread 2
« Reply #520 on: 06/13/2016 07:09 PM »
Giving up a large and still expanding LEO presence for the occasional BEO mission is not a good trade in my opinion.

NASA won't be giving anything up, as there is no international support past 2024 to keep ISS going making your point moot.
NASA has repeatedly said it wants LEO research capability beyond 2024.
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Offline Khadgars

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Re: SLS General Discussion Thread 2
« Reply #521 on: 06/13/2016 07:25 PM »
Giving up a large and still expanding LEO presence for the occasional BEO mission is not a good trade in my opinion.

NASA won't be giving anything up, as there is no international support past 2024 to keep ISS going making your point moot.
NASA has repeatedly said it wants LEO research capability beyond 2024.

Not via ISS.  My whole point is, once ISS comes down NASA's budget can make Mars missions work.


Offline Kansan52

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Re: SLS General Discussion Thread 2
« Reply #522 on: 06/13/2016 07:29 PM »
The vehicle doesn't matter. The mission matters. Congress has forgotten that. Give NASA a mission and allow them to work it. Might be SLS, might be something else. But whatever mission is selected, NASA needs to be funded enough to accomplish the mission. IMHO NASA does not have enough funding to do every task that has been mandated by Congress.

Online PahTo

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Re: SLS General Discussion Thread 2
« Reply #523 on: 06/13/2016 07:41 PM »

Thanks AnalogMan.  For anyone:  will they be able to use this adapter between the EUS and 5 meter payloads (ostensibly Orion+SM) when that variant flies?

Online whitelancer64

Re: SLS General Discussion Thread 2
« Reply #524 on: 06/13/2016 08:01 PM »

Thanks AnalogMan.  For anyone:  will they be able to use this adapter between the EUS and 5 meter payloads (ostensibly Orion+SM) when that variant flies?

No. This adapter will be used only one time, for the SLS flight with the Interim Cryogenic Propulsion Stage. A shorter "Universal Stage Adapter" will be made for the EUS / Orion.
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Offline psloss

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Re: SLS General Discussion Thread 2
« Reply #525 on: 06/28/2016 01:10 AM »
We got to see one of the center segments for EM-1 already made at the NASA Social today. Don't know if it's for left or right hand booster. Again this is SLS flight hardware, the 1st segment that came through the final assembly building.
Nice -- was this picture via Orbital ATK?  They told us no pictures on our tour, but we could request photo subjects that would then get a safety check for things like ITAR.  The only other detail I heard when we went through Final Assembly was that it was a forward-center segment.

Online Chris Bergin

Re: SLS General Discussion Thread 2
« Reply #526 on: 06/28/2016 01:36 AM »
We got to see one of the center segments for EM-1 already made at the NASA Social today. Don't know if it's for left or right hand booster. Again this is SLS flight hardware, the 1st segment that came through the final assembly building.
Nice -- was this picture via Orbital ATK?  They told us no pictures on our tour, but we could request photo subjects that would then get a safety check for things like ITAR.  The only other detail I heard when we went through Final Assembly was that it was a forward-center segment.


They were tweeting various photos, not sure about that one.

https://twitter.com/OrbitalATK

Online Bubbinski

Re: SLS General Discussion Thread 2
« Reply #527 on: 06/29/2016 01:18 AM »
We were allowed to take pics in the final assembly building. We all got excited when we heard that and took some pics. We weren't allowed to take pics anywhere else on our tour. That pic was mine, I only wish I'd thought to bring my Coolpix in instead of my iPad camera which I used.
I'll even excitedly look forward to "flags and footprints" and suborbital missions. Just fly...somewhere.

Offline Endeavour_01

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Re: SLS General Discussion Thread 2
« Reply #528 on: 06/29/2016 09:32 PM »
We were allowed to take pics in the final assembly building. We all got excited when we heard that and took some pics. We weren't allowed to take pics anywhere else on our tour. That pic was mine, I only wish I'd thought to bring my Coolpix in instead of my iPad camera which I used.

Great pic Bubbinski. It is so good to see actual flight hardware coming down the pipe. Can't wait to see this bird fly.  :D
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 psloss

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Re: SLS General Discussion Thread 2
« Reply #529 on: 07/08/2016 01:55 PM »
We got to see one of the center segments for EM-1 already made at the NASA Social today. Don't know if it's for left or right hand booster. Again this is SLS flight hardware, the 1st segment that came through the final assembly building.
Nice -- was this picture via Orbital ATK?  They told us no pictures on our tour, but we could request photo subjects that would then get a safety check for things like ITAR.  The only other detail I heard when we went through Final Assembly was that it was a forward-center segment.
Orbital ATK posted images that they captured during the media tour on Flickr; there are a couple of images of the EM-1 segment in the album:
https://www.flickr.com/photos/orbital-atk/sets/72157670004069052

Offline WindyCity

Re: SLS General Discussion Thread 2
« Reply #530 on: 07/23/2016 12:52 AM »
Bob Zimmerman (aerospace historian and award-winning author of Leaving Earth: Space Stations, Rival Superpowers, and the Quest for Interplanetary Travel) has prepared a study for the think tank Center for A New American Security to be released in August that takes a critical look at NASA's two-pronged strategy for human space flight involving SLS/Orion and commercial space. In a fascinating two-hour Space Show interview, he previews many of his conclusions. Go to http://www.thespaceshow.com/show/28-jun-2016/broadcast-2728-bob-zimmerman to listen to the interview.

In brief, he takes a highly negative view of the SLS/Orion program because of its high costs, legacy architecture, long R&D timeline, low launch cadence, and mission objectives. Listening to the interview was well worth my time. He praises the work being done by SpaceX, Blue Origin, and Bigelow Aerospace.
« Last Edit: 07/23/2016 12:56 AM by WindyCity »

Offline Oli

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Re: SLS General Discussion Thread 2
« Reply #531 on: 07/23/2016 09:30 PM »
In brief, he takes a highly negative view of the SLS/Orion program because of its high costs, legacy architecture, long R&D timeline, low launch cadence, and mission objectives. Listening to the interview was well worth my time. He praises the work being done by SpaceX, Blue Origin, and Bigelow Aerospace.

He makes his arguments in the first 5 minutes, the rest is not particularly interesting. IMO he puts to much emphasis on "commercial is so much more awesome" instead of the fact that SLS/Orion has nowhere to fly to.

I was recently thinking about how to make SLS into an effective LEO launcher, since SEP will eat away the benefit of SLS's high BEO capacity. The problem is that in such a case even less SLS launches will be needed (EMC can already be done with 2 SLS per year without using SEP for LEO to LDRO).

If Orbital/ATK gets its all-solid rocket maybe the monster can be slayed?

Sorry if OT.

Offline Chalmer

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Re: SLS General Discussion Thread 2
« Reply #532 on: 08/03/2016 08:42 PM »
So I have been wondering for awhile now about the RS-25 testing.

I mean what are they testing? Shouldn't the RS-25 be very well understood with all that test and flight history from shuttle?

As best as I can surmise from the #Journeytomars PR press releases there is an upgraded controller and it will use 109% thrust and not 104.5% thrust as under shuttle.

Is that it?

Offline Khadgars

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Re: SLS General Discussion Thread 2
« Reply #533 on: 08/03/2016 09:04 PM »
So I have been wondering for awhile now about the RS-25 testing.

I mean what are they testing? Shouldn't the RS-25 be very well understood with all that test and flight history from shuttle?

As best as I can surmise from the #Journeytomars PR press releases there is an upgraded controller and it will use 109% thrust and not 104.5% thrust as under shuttle.

Is that it?

From NASA's website;

Quote
The July 29 test and four future scheduled firings in the current series are focused on the new engine controller and higher operating parameters. While RS-25 engines are among the most tested – and proven – in the world, they have been modernized for SLS. The developmental tests are designed to show they will meet the new parameters of the rocket. During the firings, the test team will put the engine through a variety of adaptations, starting it at different temperatures and pressures, for instance. The team also will watch closely to ensure the new engine controller functions as needed. In addition to the existing RS-25 engines, NASA has contracted with Aerojet Rocketdyne to build additional engines for use on SLS missions. All flight testing for SLS take place at Stennis, as will the actual core stage testing for the first integrated mission of SLS and NASA’s Orion spacecraft, Exploration Mission-1. The next scheduled RS-25 developmental test at Stennis is set for Aug. 18.

Testing is always a good thing.

Offline redliox

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Re: SLS General Discussion Thread 2
« Reply #534 on: 08/03/2016 09:25 PM »
In brief, he takes a highly negative view of the SLS/Orion program because of its high costs, legacy architecture, long R&D timeline, low launch cadence, and mission objectives. Listening to the interview was well worth my time. He praises the work being done by SpaceX, Blue Origin, and Bigelow Aerospace.

He makes his arguments in the first 5 minutes, the rest is not particularly interesting. IMO he puts to much emphasis on "commercial is so much more awesome" instead of the fact that SLS/Orion has nowhere to fly to.

I was recently thinking about how to make SLS into an effective LEO launcher, since SEP will eat away the benefit of SLS's high BEO capacity. The problem is that in such a case even less SLS launches will be needed (EMC can already be done with 2 SLS per year without using SEP for LEO to LDRO).

If Orbital/ATK gets its all-solid rocket maybe the monster can be slayed?

Sorry if OT.

I don't see the SLS as a monster, but the Orion atop it could be an annoying goblin.

The SLS itself was produced as the best compromise available based on the Augustine Commission's demands, as best they could be interpreted at the time.  So I find it a bad comedy when people complain about it now.  The space shuttle's reuseability was seen as an expensive liability, so it was cut out; and ironically people nowadays complain it's not reusable like the Falcon 9 first stage.  They thought basing it off mainly shuttle components would save the workforce, whereas now they complain it's old tech.  For crying out loud people!

I'd say slay the Orion, keep the SLS, and use commercial flights.  I could see the SLS easily flying an empty Mars or Lunar lander into LEO and whatever equipment, and then a smaller commercial launcher deliver the humans separately.  That would be the best compromise to me.
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Offline Proponent

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Re: SLS General Discussion Thread 2
« Reply #535 on: 08/03/2016 09:30 PM »
Augustine did not demand an SLS-sized heavy lifter.  It offered the possibility of using a rocket with a capacity of 50-ish tonnes to LEO, possibly commercially managed.

In any event, regardless of launch vehicle, Augustine said that NASA needed an extra $3 billion per year (which would be more now) if it were to do much of anything.

Offline Kansan52

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Re: SLS General Discussion Thread 2
« Reply #536 on: 08/03/2016 10:42 PM »
It's be a while since reading the report, but memory says there was a chart that said the only mores expensive (as a launch system) then Ares I/Orion was anything else/Orion (which is the result we have exists now).

Has memory skewed that or was that a basic observation in the report?

Offline Zed_Noir

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Re: SLS General Discussion Thread 2
« Reply #537 on: 08/06/2016 08:26 AM »
We got a FISO presentation titled "NASA's Space Launch System: Powering the Journey to Mars" by Chris Saunders (AJ), Mike Fuller (Orb-ATK), & Bob DaLee (Boeing) on August 3. Links to the audio & slide presentations below.

Slides link

Audio link


Slide of the various SLS variants and slide of various launch vehicles with  performance charts to various orbits from the slide presentations.

Offline Khadgars

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Re: SLS General Discussion Thread 2
« Reply #538 on: 08/06/2016 03:39 PM »
Thank you for the links.  I like seeing EM-2 at 2021  ;D

Online oldAtlas_Eguy

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Re: SLS General Discussion Thread 2
« Reply #539 on: 08/06/2016 04:09 PM »
An excellently done presentation. The one item conspicuously missing is costs. If you add the $/mt for the different orbits for each vehicle the story changes significantly as to the advantages and disadvantages for the LVs depicted.

But otherwise the relative capabilities chart is an excellent reference item.

Added:
Estimate of what the cost data would look like.
Cost/flt ($M)LEO GEO Lunar Mars
VehiclePayload (mt)Cost/mt ($M)Payload (mt)Cost/mt ($M)Payload (mt)Cost/mt ($M)Payload (mt)Cost/mt ($M)
Atlas V$22418.8$11.98.9$25.28.9$25.26$37.3
F9$6222.8$2.78.3$7.58.3$7.54.02$15.4
DIVH$45028.37$15.913.81$32.613.81$32.610$45
FH$13054.4$2.422.2$5.919.8$6.613.6$9.6
SLS 1B$1000105$9.542.5$23.538$26.330$33.3
SLS 2B$800130$6.262$12.946$17.442.5$18.8
Vulcan$18033$5.515.6$11.515.6$11.510.5$17.1
Vulcan Distributed Launch$340$33$10.333$10.333$10.3

I used a lower per flt cost for SLS 2B in the hope that the cost per flt would go down with more use.

Edit #2: I decided to add Vulcan with ACES to the table just to see where it lies in the comparisons on $M/mt.
« Last Edit: 08/06/2016 09:10 PM by oldAtlas_Eguy »

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