Author Topic: SLS General Discussion Thread 2  (Read 226234 times)

Offline Khadgars

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Re: SLS General Discussion Thread 2
« Reply #180 on: 10/02/2015 06:30 PM »
I'm pretty sure that Jim meant "there is now only one pad for SLS", since NASA leased pad 39A to SpaceX. The implication is that SLS cannot have a higher launch rate e.g. Shuttle because of the limitation of a single SLS launch pad 39B.

There is one pad and one ML. Original maps of Complex 39 show locations for 5 potential pads, but it is doubtful in the extreme that any more would ever be developed. Even if they wanted to, environmental impact reviews would most surely prevent it anyway.

Wow, I didn't think it was that hard of a question. Or that the possibility of a second ML being built was so far out there. And I never said anything about building any more launch pads. I just wanted to know if making a clean pad was of any benefit whatsoever to possible future launch rates.

So now that we know that NASA will never build another ML or have more than one launch pad. How long will it take NASA to launch all of the SLS needed for one complete current Mars DRM mission, given one ML, one pad, and one VAB high bay. Have they gotten the number of launches below 10 yet?

Remember, we're on a Journey to Mars(TM)!!

Thanks.

I thought the article pretty much spelled that out.
From the article.
Quote
Mars 2039:

Build up for the first human Mars mission would commence in 2033 with the launch of an SLS mission to deliver the TEI stage to Cis-lunar space.

This would be followed in 2034 by the launch of the first two Mars Surface Landers on two separate SLS missions.

The year 2035 would then see two more SLS missions, with the launches of the third and fourth Mars Surface Landers.

This would be followed in 2036 with the launch of the fifth and final Mars Surface Lander.

With the launch of the fifth lander, all pre-deployment payloads for the first human Mars mission will have been launched.

The year 2036 would then see the launch of the EOI stage before the 2037 launches of the MOI and TMI stages on two separate SLS launches.

In 2038, a crewed mission of Orion and SLS would bring a check out crew on a restock mission to the Mars Transit Habitat — which would have returned to Cis-lunar space in late 2035 from the human Phobos mission.

If those checkouts and restocks are successful, the first crew for Mars would then launch in 2039 to the Mars Transit Habitat before departing Cis-lunar space for Mars.

Assuming a nominal mission, a single SLS flight would be needed in 2042 to launch an Orion capsule to retrieve the first Mars crew and their cargo following their return to Cis-lunar space.

For the first human mission to Mars, SLS’s launch campaign will see it deliver 630.7t of mass to Cis-lunar space.

Offline Mark S

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Re: SLS General Discussion Thread 2
« Reply #181 on: 10/02/2015 06:45 PM »
You're right, of course. NSF always has the full scoop.

Thanks.

Offline TomH

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Re: SLS General Discussion Thread 2
« Reply #182 on: 10/02/2015 08:20 PM »
I'm pretty sure that Jim meant "there is now only one pad for SLS", since NASA leased pad 39A to SpaceX. The implication is that SLS cannot have a higher launch rate e.g. Shuttle because of the limitation of a single SLS launch pad 39B.

There is one pad and one ML. Original maps of Complex 39 show locations for 5 potential pads, but it is doubtful in the extreme that any more would ever be developed. Even if they wanted to, environmental impact reviews would most surely prevent it anyway.

Wow, I didn't think it was that hard of a question. Or that the possibility of a second ML being built was so far out there. And I never said anything about building any more launch pads. I just wanted to know if making a clean pad was of any benefit whatsoever to possible future launch rates.

Feeling a bit sensitive today? Where did all that come from?

Remember, we're on a Journey to Mars(TM)!!

No we're not. We're sending pork to particular states and districts that used to build STS parts. No money at all is allocated to do anything on Mars. And likely never will be.

Offline Khadgars

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Re: SLS General Discussion Thread 2
« Reply #183 on: 10/02/2015 08:29 PM »
I'm pretty sure that Jim meant "there is now only one pad for SLS", since NASA leased pad 39A to SpaceX. The implication is that SLS cannot have a higher launch rate e.g. Shuttle because of the limitation of a single SLS launch pad 39B.

There is one pad and one ML. Original maps of Complex 39 show locations for 5 potential pads, but it is doubtful in the extreme that any more would ever be developed. Even if they wanted to, environmental impact reviews would most surely prevent it anyway.

Wow, I didn't think it was that hard of a question. Or that the possibility of a second ML being built was so far out there. And I never said anything about building any more launch pads. I just wanted to know if making a clean pad was of any benefit whatsoever to possible future launch rates.

Feeling a bit sensitive today? Where did all that come from?

Remember, we're on a Journey to Mars(TM)!!

No we're not. We're sending pork to particular states and districts that used to build STS parts. No money at all is allocated to do anything on Mars. And likely never will be.

I keep hearing that.  But one thing no one mentions is the $4 Billion ISS budget.

Once that program is done, the entire NASA HSF budget of $9 Billion would be enough to support a Phobos/Mars program with international support imo.

Offline sdsds

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Re: SLS General Discussion Thread 2
« Reply #184 on: 10/02/2015 08:41 PM »
one thing no one mentions is the $4 Billion ISS budget. [...] Once that program is done, the entire NASA HSF budget of $9 Billion would be enough to support a Phobos/Mars program with international support imo.

Some aspects of ISS get mentioned a lot. In particular, commercial crew. It's a bit circuitous but commercial crew removes dependence on Russia, and thus enables replacing ISS with a new international LEO station in which Russia is not one of the partners. The perfect vehicle to launch that station (or at least the lion's share of its mass) is ... SLS!
« Last Edit: 10/02/2015 08:41 PM by sdsds »
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Online spacenut

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Re: SLS General Discussion Thread 2
« Reply #185 on: 10/02/2015 08:54 PM »
When FH comes on line, two Bigelow 330 modules will be about the size of the ISS now, with only two FH launches, at about half the price of SLS.  With reusable rockets with SpaceX and engines with ULA, prices to launch will come down and SLS will become too expensive to launch except for very large payloads.  Even then Vulcan with ACES and solids could do probably 40 tons or more.  A 3 core Vulcan could match FH from Space X.  As reuse comes down, used rockets or engines will make cargo type payloads much cheaper.  SLS will only be able to deliver 105 tons to LEO and it won't be cheap.  Also with SEP tugs to move 40-50 ton payloads around, in orbit or L1 assembly for large spacecraft to Mars or the probes to the outer solar system can be done with the reusable rockets.  I predict SLS will be cancelled by the mid 2020's especially if SpaceX comes through with the reusable MCT.  SLS should have been made reusable, with fly back or land back boosters, a plug nozzle engine on the core to land back the core.  Then it would have been less expensive to operate being reusable. 

Offline sdsds

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Re: SLS General Discussion Thread 2
« Reply #186 on: 10/02/2015 09:10 PM »
two Bigelow 330 modules will be about the size of the ISS now, with only two FH launches, at about half the price of SLS. [...] I predict SLS will be cancelled by the mid 2020's 

Yes, that might happen. By then we'll know so much more about SpaceX and Bigelow and what they can accomplish! Perhaps they will be able to work with ESA and JAXA on an international LEO station. It might be fun to discuss that on another thread.

The question that's relevant here is whether NASA could leverage its ISS experience with ESA and JAXA in a fairly straight-forward way to create an International Skylab, launched on SLS. I think they could!

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Offline RonM

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Re: SLS General Discussion Thread 2
« Reply #187 on: 10/02/2015 09:16 PM »
two Bigelow 330 modules will be about the size of the ISS now, with only two FH launches, at about half the price of SLS. [...] I predict SLS will be cancelled by the mid 2020's 

Yes, that might happen. By then we'll know so much more about SpaceX and Bigelow and what they can accomplish! Perhaps they will be able to work with ESA and JAXA on an international LEO station. It might be fun to discuss that on another thread.

The question that's relevant here is whether NASA could leverage its ISS experience with ESA and JAXA in a fairly straight-forward way to create an International Skylab, launched on SLS. I think they could!

NASA has stated they won't build another LEO space station. SLS could be used for a cis-lunar station. Perhaps a gateway station at EML-2.

ESA, JAXA, and Russia could work with China on the Chinese space station. Bigelow or someone else could build a commercial space station. Obviously, SLS would not be a part of that.

Offline 93143

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Re: SLS General Discussion Thread 2
« Reply #188 on: 10/02/2015 09:50 PM »
Bigelow or someone else could build a commercial space station. Obviously, SLS would not be a part of that.

I don't know about that.  As far as I know, it's got a decent shot at being the only rocket available capable of lofting a BA-2100...  not that you'd necessarily want to start with something of that scale, but the fact remains that Bigelow has advertised the thing...

Offline robertross

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Re: SLS General Discussion Thread 2
« Reply #189 on: 10/02/2015 10:48 PM »
1.  Someone said, somewhere here, that when facility to manufacture Saturn V 1st and 2nd stages were for 6 Saturn V's per year.  So, the facility can at least do 6.

2.  The VAB can process at least 4 at a time.  It has 4 bays.  They would have to build at least 4 platforms.   

1.  Not true.  Space/volume does not determine capability.  The tooling does.  Anyways, it is a shared facility and there are other users

2.  See above. The 4 bays were never fully outfitted and even during shuttle, only two were outfitted.  Also, there is not only one pad for SLS.

Also, IIRC doesn't the quantity-distance rules on the SRBs mean they are only allowed to have two SLS vehicles in the VAB at one time, or am I misremembering that detail?

~Jon

Somewhere on L2 there was nice overview of the VAB facility and the maximum number of SRB segments allowed in there. I thought it was 10 segments total.
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Offline Mark S

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Re: SLS General Discussion Thread 2
« Reply #190 on: 10/03/2015 02:11 AM »
Feeling a bit sensitive today? Where did all that come from?

Ha! You should have seen my post before I self-censored it. LOL.

So, now the consensus is that there will only be one ML, thus the minimum time between SLS launches will be however long it takes to stack one up in the VAB. Does anyone have an idea about how long that may be?

Which then brings us back to the Mars mission proposals mentioned in the recent article, as Khadgars kindly pointed out. One proposal has two SLS launches of equipment to Mars in 2034, 2035, and 2036. (Five landers and the EOI stage.)

I'm no orbital expert, but I thought that Mars missions were normally spaced out every two years due to the relationship between Earth's and Mars' orbits. Is it possible to launch large payloads to Mars in the "off" years?

And, going back to the minimum time between SLS launches, how large is the launch window for Mars missions in the "on" years? Is it possible that a delay in the stacking of the second SLS in a sequence would cause it to miss the launch window?

Thanks.
« Last Edit: 10/03/2015 02:14 AM by Mark S »

Offline jongoff

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Re: SLS General Discussion Thread 2
« Reply #191 on: 10/03/2015 02:59 AM »
1.  Someone said, somewhere here, that when facility to manufacture Saturn V 1st and 2nd stages were for 6 Saturn V's per year.  So, the facility can at least do 6.

2.  The VAB can process at least 4 at a time.  It has 4 bays.  They would have to build at least 4 platforms.   

1.  Not true.  Space/volume does not determine capability.  The tooling does.  Anyways, it is a shared facility and there are other users

2.  See above. The 4 bays were never fully outfitted and even during shuttle, only two were outfitted.  Also, there is not only one pad for SLS.

Also, IIRC doesn't the quantity-distance rules on the SRBs mean they are only allowed to have two SLS vehicles in the VAB at one time, or am I misremembering that detail?

~Jon

Somewhere on L2 there was nice overview of the VAB facility and the maximum number of SRB segments allowed in there. I thought it was 10 segments total.

Ok, so I'm not misremembering things. So that would prevent having more than two SLS's in the building at any given time. One of the joys of big SRBs...

~Jon

Offline Coastal Ron

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Re: SLS General Discussion Thread 2
« Reply #192 on: 10/03/2015 03:00 AM »
NASA has stated they won't build another LEO space station.

Gerstenmaier said just this year:

At some point this space station will wear out and there needs to be a follow-on space station,”...“What we’re hoping for is that the private sector picks that up.

But based on comments NASA has made about the importance of the ISS for preparing for Mars, I'd say they are talking about an LEO commercial station.

Quote
SLS could be used for a cis-lunar station. Perhaps a gateway station at EML-2.

You have to consider what the goal of a cis-lunar station would be, within the context of NASA's current direction.  If it's to continue the work the ISS was not able to complete in support of going to Mars, then putting it 1,000X further away is not going to be very economical.

As to possible commercial stations, NASA did a study (referenced in this NSF article) that said a notional Bigelow BA-2100 could fly on a Falcon Heavy.  And if it is a commercial station, then cost will be a big factor for whoever is building it.  Certainly an SLS could lift it, but whether it makes sense from a cost standpoint is another matter.

Quote
ESA, JAXA, and Russia could work with China on the Chinese space station. Bigelow or someone else could build a commercial space station. Obviously, SLS would not be a part of that.

All of those countries have challenging economies right now, with some more than others (i.e. Russia).  I think China will proceed with their station plans for LEO, but I think it will be a while until everyone else has the money to pursue another expensive space endeavor.
If we don't continuously lower the cost to access space, how are we ever going to afford to expand humanity out into space?

Offline 93143

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Re: SLS General Discussion Thread 2
« Reply #193 on: 10/03/2015 03:25 AM »
As to possible commercial stations, NASA did a study (referenced in this NSF article) that said a notional Bigelow BA-2100 could fly on a Falcon Heavy.

That's not exactly what it said:

"Although the Olympus module is being offered as a potential payload for SLS, the Gate 1 Report indicates that it could possibly also be launched on a Falcon Heavy."

As I understand it, there is/was some doubt as to whether the mass will end up low enough.  Certainly the earlier numbers were nowhere near what Falcon Heavy could manage, and scaling a BA-330 by the 2/3 power of the volume difference ends up close to 70 tonnes.  However, the reports are not public, and I can't find the relevant portion in L2.

More to the point, it seems SLS was the LV of choice when that report was submitted (it wasn't a NASA study as such; it was a submission by Bigelow under a Space Act Agreement).
« Last Edit: 10/03/2015 03:41 AM by 93143 »

Offline Coastal Ron

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Re: SLS General Discussion Thread 2
« Reply #194 on: 10/03/2015 03:53 AM »
As I understand it, there is/was some doubt as to whether the mass will end up low enough.

Keep in mind that the BA-2100 is a concept, not reality.  It can be whatever Bigelow wants it to be - SLS sized, Falcon Heavy sized, etc.  It will depend on what the requirements are, and so far there are no firm requirements.  It certainly is not part of the current Mars plan, and that plan consumes all of NASA's forecasted budget for two decades.
If we don't continuously lower the cost to access space, how are we ever going to afford to expand humanity out into space?

Offline 93143

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Re: SLS General Discussion Thread 2
« Reply #195 on: 10/03/2015 04:13 AM »
You do realize the name actually includes its volume in cubic metres, right?

It is, as you say, a concept, and it's already been thought of.  It's roughly SLS-sized.  It might fit on Falcon Heavy; that would be great.

EDIT:  After double-checking a bit, it seems my memory was correct; from what we know, BA-2100 is not close to being light enough for the 53-tonne Falcon Heavy to lift it.  Some sort of upgrade would be required.
« Last Edit: 10/03/2015 06:41 AM by 93143 »

Offline Endeavour_01

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Re: SLS General Discussion Thread 2
« Reply #196 on: 10/03/2015 04:14 AM »
\Which then brings us back to the Mars mission proposals mentioned in the recent article, as Khadgars kindly pointed out. One proposal has two SLS launches of equipment to Mars in 2034, 2035, and 2036. (Five landers and the EOI stage.)

I'm no orbital expert, but I thought that Mars missions were normally spaced out every two years due to the relationship between Earth's and Mars' orbits. Is it possible to launch large payloads to Mars in the "off" years?

The once every two years is for direct TMI using chemical propulsion. With SEP you shouldn't have the time constraint.

When FH comes on line, two Bigelow 330 modules will be about the size of the ISS now, with only two FH launches, at about half the price of SLS. 

Launching payloads to LEO smaller than 50 mt should go to FH or Vulcan whenever possible. Your example of launching a new LEO commercial space station is a great idea. In my view SLS and commercial vehicles should complement each other. SLS handles big payloads (above 50 mt) to LEO and the BLEO crew and cargo while FH and Vulcan handle smaller missions to LEO and BEO (say launching a Dragon as a resupply craft to a lunar space station).
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 a_langwich

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Re: SLS General Discussion Thread 2
« Reply #197 on: 10/03/2015 04:15 AM »

I keep hearing that.  But one thing no one mentions is the $4 Billion ISS budget.

Once that program is done, the entire NASA HSF budget of $9 Billion would be enough to support a Phobos/Mars program with international support imo.

That's funny, because I keep hearing THAT, once we kill off ISS that's $4 billion to spend on wonderful things.  Let's take a look, shall we?

https://oig.nasa.gov/audits/reports/FY15/IG-15-021.pdf

Table 1, you can follow along...

ISS budget request for FY 2016 = 3.106 billion. 
Subdivided into
  -- commercial crew and cargo  = 1.606 billion
  -- operations and maintenance = 1.106 billion
  -- research = 394 million

You can dig through the OIG audit of some of the contracts for the different areas, and ask yourself:  is this capability going to disappear, or is it likely going to be needed in some other form going forward? 

For example, commercial crew and commercial cargo are arguably driving some of the biggest transformations in the launch industry.  Sure, after some future president knifes the ISS, those won't be needed...but isn't it reasonable to assume NASA will still want some crew and cargo transported to some other LEO destination, even if it were a commercial station?  As far as I can see, the need for LEO operations will never cease as long as humans are spacefaring, it's just a matter of how to partition it into commercial and government-led.

Do you see Bigelow stepping up to a rigorous permanently manned mission control for a permanently manned station, capable of safely overseeing station operations, conducting research or collecting data over year-long time scales?  That's probably what NASA would need, if they were going to be a customer.  I don't see that, but to be fair they may develop quite a bit if they get going.  But that's another sticking point, right now it looks like Bigelow has given up on a non-governmental marketplace, and so in addition to commercial crew and commercial cargo, they would need a commercial station funding contract. 

Or what about the only manned Mission Control Center, the only manned mission planning office, or the Neutral Buoyancy Lab, or the spacesuit design and testing office?  Isn't it likely they will be required in whatever future manned endeavors NASA undertakes?

Rather than eyeing the ISS budget as free extra money, it's more realistic to assume that ISS Operations will probably transition to BEO Operations, and there will likely still be a fair amount of NASA-supported LEO activity.  Supported, I should say, not as a jobs program, but because the needs/benefits outweigh the costs.

Even the Boeing contract to support ISS will have a very similar counterpart in an future contracts to support SLS, Orion, and the various habitation and exploration modules.

Killing ISS then, in my opinion, should* free up very little to nothing to help DEVELOP new modules or systems, but it might get converted to the budget slice for operations and management of SLS and BEO missions.

*I say SHOULD because of course in some fantasy world you could shut the doors at JSFC, and throw away the manned mission control capability, and the spacesuit expertise, and the planning and Neutral Buoyancy Center testing, and so on, and use nearly the full $3 billion for development.  But it seems fairly clear this would be a colossal blunder--sacrificing capabilities that will be needed in the near future, and expensive-to-impossible to re-constitute at the same expertise level--and politically impossible as well.

Offline sdsds

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Re: SLS General Discussion Thread 2
« Reply #198 on: 10/03/2015 04:24 AM »
NASA has stated they won't build another LEO space station.

I agree that powerful people (including I think NASA Administrator Charlie Bolden) say that, and it reflects the view of the President of the United States. But in 2020 I do not believe Charlie Bolden will be NASA Administrator, and I am 100% certain President Obama will no longer occupy the Oval Office!
« Last Edit: 10/03/2015 04:24 AM by sdsds »
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Offline A_M_Swallow

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Re: SLS General Discussion Thread 2
« Reply #199 on: 10/03/2015 05:49 AM »

NASA has stated they won't build another LEO space station. SLS could be used for a cis-lunar station. Perhaps a gateway station at EML-2.

ESA, JAXA, and Russia could work with China on the Chinese space station. Bigelow or someone else could build a commercial space station. Obviously, SLS would not be a part of that.

NASA may be willing to rent time on a LEO spacestation. If it rents large amounts of time NASA may be able to convince Congress to buy/lease the spacestation. Although the politicians may want to get involved with the negotiations.

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