Author Topic: SLS-a step forward or back to square one?  (Read 199619 times)

Offline TomH

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Re: SLS-a step forward or back to square one?
« Reply #20 on: 04/08/2012 11:01 pm »
Context is everything.  EDS also means Earth Departure Stage.

I completely agree, and respectfully, I thought I gave enough context to imply which EDS I meant. Again, my apologies for not being clear enough.

Perhaps I should have referred to the unfunded SAA of July, 2011 between NASA and ULA to human rate Atlas V. In this article, Chris uses the term EDS:

http://www.nasaspaceflight.com/2011/07/nasa-ula-saa-complete-human-rating-atlas-v/
« Last Edit: 04/08/2012 11:02 pm by TomH »

Offline clongton

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Re: SLS-a step forward or back to square one?
« Reply #21 on: 04/08/2012 11:03 pm »
My apologies for not having the exactly correct terminology.

Don't fret too much Tom - stick around and you'll be fine.

You are referring to the Atlas CCB (Common Core Booster). It is the first stage of the Atlas-V and if utilized as an SLS booster, would be the SLS LRB (Liquid Rocket Booster) as well as the Orion crew launcher in the Heavy configuration. There is the synergy with Commercial Crew: the Atlas-V's CCB can serve in four (4) ways:

1. DoD defense launcher
2. NASA science launcher
3. Commercial Crew launcher
4. SLS LRB booster.
« Last Edit: 04/08/2012 11:07 pm by clongton »
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Offline FinalFrontier

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Re: SLS-a step forward or back to square one?
« Reply #22 on: 04/08/2012 11:09 pm »
....
Ares did have the 1.5 launch architecture. Ares V was cargo only while SLS will have an EDS to make it human rated. Some tweaks I have suggested to SLS are making it scalable with more than two (liquid advanced) boosters and giving it a 1.5 architecture with SLS non human rated and Orion going to LEO/EOR atop DIVH, AVH, or AVP2 prior to deep space departure. ....
I particularly think that is a good idea. SLS needs all the help it can get in being cheaper.

I also liked the concept of the 1.5 architecture but the Ares-I was the worst possible vehicle for a CLV. Note the huge amount of work done on the AJAX threads. That was the equivolant of the early SLS using the Atlas as both LRB and CLV. If it were not for the early requirement to use the SRB on SLS  Block-I NASA would have been well advised to go that route. The larger versions would have been every bit the equal of the SLS Block II.

It is my guess that when EFT-1 happens, a whole lot of people on the outside will suddenly start asking, "Why can't NASA just go ahead and launch the crew on this rocket?" Likely some congressman will summon the NASA administrator before congress for an inquiry. I imagine we will hear questions like this:

"Can ULA adapt the Atlas V CC EDS to the DIVH and launch a crewed Orion?"

"Can ULA extend its AV EDS to an AVH?"

"Is SLS too far along in man rating to make it cargo only and use Atlas or Delta in a 1.5 launch architecture? If not, how much would be saved by doing this and how would time lines be affected?" And likely the answer will be, "Well, it could have been done and would have saved time and money if we had done that in the beginning, but that was not the mandate you gave us; we did what you ordered us to do."

Granted, SLS parameters were likely set before three CCDev participants selected AV as the LV and the memorandum was signed to develop an EDS to human rate AV, however it sometimes makes sense to say, "Hey, how could we leverage this to our advantage in other ways?"

...It might be.  The SLS Block 1A booster type is yet to be determined.  It could turn out to be an advanced solid...

 :'( Let's hope not. RP-1 booster is better on so many levels.

That's my personal preference and hope.
Solids are very powerful but oh so very limited!
Liquids are MUCH better than solids for manned applications in my opinion.


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Offline clongton

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Re: SLS-a step forward or back to square one?
« Reply #23 on: 04/08/2012 11:14 pm »
....
Ares did have the 1.5 launch architecture. Ares V was cargo only while SLS will have an EDS to make it human rated. Some tweaks I have suggested to SLS are making it scalable with more than two (liquid advanced) boosters and giving it a 1.5 architecture with SLS non human rated and Orion going to LEO/EOR atop DIVH, AVH, or AVP2 prior to deep space departure. ....
I particularly think that is a good idea. SLS needs all the help it can get in being cheaper.

I also liked the concept of the 1.5 architecture but the Ares-I was the worst possible vehicle for a CLV. Note the huge amount of work done on the AJAX threads. That was the equivolant of the early SLS using the Atlas as both LRB and CLV. If it were not for the early requirement to use the SRB on SLS  Block-I NASA would have been well advised to go that route. The larger versions would have been every bit the equal of the SLS Block II.

It is my guess that when EFT-1 happens, a whole lot of people on the outside will suddenly start asking, "Why can't NASA just go ahead and launch the crew on this rocket?" Likely some congressman will summon the NASA administrator before congress for an inquiry. I imagine we will hear questions like this:

"Can ULA adapt the Atlas V CC EDS to the DIVH and launch a crewed Orion?"

"Can ULA extend its AV EDS to an AVH?"

"Is SLS too far along in man rating to make it cargo only and use Atlas or Delta in a 1.5 launch architecture? If not, how much would be saved by doing this and how would time lines be affected?" And likely the answer will be, "Well, it could have been done and would have saved time and money if we had done that in the beginning, but that was not the mandate you gave us; we did what you ordered us to do."

Granted, SLS parameters were likely set before three CCDev participants selected AV as the LV and the memorandum was signed to develop an EDS to human rate AV, however it sometimes makes sense to say, "Hey, how could we leverage this to our advantage in other ways?"

...It might be.  The SLS Block 1A booster type is yet to be determined.  It could turn out to be an advanced solid...

 :'( Let's hope not. RP-1 booster is better on so many levels.

That's my personal preference and hope.
Solids are very powerful but oh so very limited!
Liquids are MUCH better than solids for manned applications in my opinion.


AJAX.

With luck, SLS Block-II will go the AJAX path with LRB's. That way they would have the Block-II capability without waiting for the CPS. Need more umph for a mission? Add another pair of LRB's. Need even more? One more pair. Ok, now we're pushing 140 tonnes. Still not enough? Ok, now add an upper stage. This path really is lego block rocketry. Energia had it right but the collapsing Russian economy killed it before it could come into its own.
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Offline TomH

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Re: SLS-a step forward or back to square one?
« Reply #24 on: 04/08/2012 11:14 pm »
My apologies for not having the exactly correct terminology.

Don't fret too much Tom - stick around and you'll be fine.

You are referring to the Atlas CCB (Common Core Booster). It is the first stage of the Atlas-V and if utilized as an SLS booster, would be the SLS LRB (Liquid Rocket Booster) as well as the Orion crew launcher in the Heavy configuration. There is the synergy with Commercial Crew: the Atlas-V's CCB can serve in four (4) ways:

1. DoD defense launcher
2. NASA science launcher
3. Commercial Crew launcher
4. SLS LRB booster.

Thanks, you must have been typing at the same time as Jim and I. The issue was which "EDS" I meant. Since Atlas V is already being human rated, it seems to make some degree of sense to at least do a study of whether extending that Emergency Detection System to either Delta IV or Atlas V Heavy, sending Orion to LEO/EOR on that LV, and eliminating the Emergency Detection System on SLS would have financial and time line advantages.

Offline clongton

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Re: SLS-a step forward or back to square one?
« Reply #25 on: 04/08/2012 11:19 pm »
Thanks, you must have been typing at the same time as Jim and I. The issue was which "EDS" I meant. Since Atlas V is already being human rated, it seems to make some degree of sense to at least do a study of whether extending that Emergency Detection System to either Delta IV or Atlas V Heavy, sending Orion to LEO/EOR on that LV, and eliminating the Emergency Detection System on SLS would have financial and time line advantages.

EDS means both Earth Departure Stage (Constellation & SLS) and Emergency Detection System (Apollo).

For SLS you are referring to the detection portion of the Flight Termination System, but I'm not sure it has an official acronym.
« Last Edit: 04/08/2012 11:22 pm by clongton »
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Offline TomH

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Re: SLS-a step forward or back to square one?
« Reply #26 on: 04/08/2012 11:22 pm »
With luck, SLS Block-II will go the AJAX path with LRB's. That way they would have the Block-II capability without waiting for the CPS. Need more umph for a mission? Add another pair of LRB's. Need even more? One more pair. Ok, now we're pushing 140 tonnes. Still not enough? Ok, now add an upper stage. This path really is lego block rocketry. Energia had it right but the collapsing Russian economy killed it before it could come into its own.

I do remember Jim making statements in other threads about thrust beam and pad issues making this impracticable. How big would those issues be if engineers in future decades decided to add more advanced liquid boosters for a Block III SLS? If those issues were resolved, would there then be problems with too much cargo mass and too much thrust force for the core to withstand?

Offline TomH

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Re: SLS-a step forward or back to square one?
« Reply #27 on: 04/08/2012 11:30 pm »

EDS means both Earth Departure Stage (Constellation & SLS) and Emergency Detection System (Apollo).

For SLS you are referring to the detection portion of the Flight Termination System, but I'm not sure it has an official acronym.

I was referencing Atlas V as a Commercial Crew launcher, specifically Chris' article in which he used the acronym EDS for Emergency Detection System. I knew EDS had two meanings, though I did not know its use was specific to which launcher one was referencing. I assumed Chris' use of the acronym in reference to Atlas was correct.

Offline TomH

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Re: SLS-a step forward or back to square one?
« Reply #28 on: 04/08/2012 11:56 pm »
Context is everything.

Yes, it is. I am not a rocket scientist, but I am smart with a broad knowledge of many subjects, one of which is writing. If the following, which is part of the post in question, doesn't give enough implied context, then I don't know what does.

...the memorandum was signed to develop an EDS to human rate AV...

Offline USFdon

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Re: SLS-a step forward or back to square one?
« Reply #29 on: 04/09/2012 12:51 am »
Still think that a combined USAF/NASA large hydrolox engine should be a goal for the future. Need to get those production numbers up.

No A hydrocarbon booster engine should be the goal

Both should be a goal. If we as a nation will continue to use government-led designed/owned rocket launchers, it would make sense to go down the path of commonality. SLS's new strap on boosters, whether kerolox (which they should be) or advanced solids, should be a launcher on their own right to keep production numbers up (maybe serve as the next generation Atlas (or AVP2)...). I don't see Delta IV going anywhere, considering the sunk investment in its tooling and launch pads.

Offline Jim

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Re: SLS-a step forward or back to square one?
« Reply #30 on: 04/09/2012 12:56 am »
Still think that a combined USAF/NASA large hydrolox engine should be a goal for the future. Need to get those production numbers up.

No A hydrocarbon booster engine should be the goal

Both should be a goal. If we as a nation will continue to use government-led designed/owned rocket launchers, it would make sense to go down the path of commonality. SLS's new strap on boosters, whether kerolox (which they should be) or advanced solids, should be a launcher on their own right to keep production numbers up (maybe serve as the next generation Atlas (or AVP2)...). I don't see Delta IV going anywhere, considering the sunk investment in its tooling and launch pads.

No, the govt should not building launch vehicles, especially in EELV/commercial classes

And no,another LH2 engine is not needed.

Offline anonymous1138

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Re: SLS-a step forward or back to square one?
« Reply #31 on: 04/09/2012 03:14 am »
Still think that a combined USAF/NASA large hydrolox engine should be a goal for the future. Need to get those production numbers up.

No A hydrocarbon booster engine should be the goal

Both should be a goal. If we as a nation will continue to use government-led designed/owned rocket launchers, it would make sense to go down the path of commonality. SLS's new strap on boosters, whether kerolox (which they should be) or advanced solids, should be a launcher on their own right to keep production numbers up (maybe serve as the next generation Atlas (or AVP2)...). I don't see Delta IV going anywhere, considering the sunk investment in its tooling and launch pads.

No, the govt should not building launch vehicles, especially in EELV/commercial classes

...


Absolutely agree with Jim. U.S. National Space Policy discourages the government from competing with commercial industry unless absolutely necessary.

Apart from that, I'd agree that SLS is - on paper - making use of some good assets to build The Big Rocket. What's backwards is that it is being built at all. There are all sorts of great stories on how this is going to eventually play out. The fact remains that over the next ten years or so $20 billion will be spent on developing and flying two SLS missions. Beyond that, who knows how many flights there will be, how much it will cost to maintain the infrastructure no matter how many flights are made, how much each individual flight will cost, and how any worthwhile payloads will be developed (when, and for how much). And if (when?) SLS is cancelled, it will be yet more billions and years wasted.

For instance (just one example), how many Atlas V launches would $20 billion buy? Rather, how many Atlas V launches would $5 billion buy, and what payloads could you develop with $10 billion? Would that extra $5 billion buy accelerated development and testing of an Atlas V Heavy? I would think so. Further, I'd call B$ on anyone who insists you need heavy lift (as defined by SLS) at all to do worthwhile BEO missions. The point is that SLS is an uncreative, old-school solution that only leverages "certain existing assets" (read into that what you will), when there are much more forward-thinking and *executable* ways to go.


« Last Edit: 04/09/2012 03:16 am by anonymous1138 »

Offline sdsds

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Re: SLS-a step forward or back to square one?
« Reply #32 on: 04/09/2012 03:38 am »
how many Atlas V launches would $5 billion buy
At 1/4 billion dollars per launch, $5 billion buys 20 launches at NASA prices. (Why is that the per launch cost? Consider that NASA will pay $446 million for the launch services associated with the GOES-R and GOES-S spacecraft, planned for October 2015 and February 2017, respectively. Each uses an Atlas V 541, and the estimated cost includes additional services for payload processing, launch vehicle integration, mission unique launch site ground support, and tracking, data and telemetry services.)

How many crewed launches on Atlas V would $5 billion buy? We don't know, since no one has yet purchased one.
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Offline TomH

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Re: SLS-a step forward or back to square one?
« Reply #33 on: 04/09/2012 04:11 am »
Once we run out of stockpiled RD-180s, what will be the cost of an Atlas V?

Offline spectre9

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Re: SLS-a step forward or back to square one?
« Reply #34 on: 04/09/2012 04:34 am »
Seems like the PWR/UTX/Goodrich stuff hasn't been sorted out yet.

As far as I know Rocketdyne has the engines NASA wants.

They're not going to want 12 AJ-26-500s.

They also are very much distasteful of the non-USA made RD-180. This is why I think AJAX/AVH isn't going to happen.

Offline TomH

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Re: SLS-a step forward or back to square one?
« Reply #35 on: 04/09/2012 05:12 am »
My perspective, as someone who is far removed from this industry, yet who has a deep interest in it, is that turf wars between government agencies is petty. The average citizen, no, let me make that the average taxpayer actually believes the FBI and CIA should cooperate in overlapping areas. The average taxpayer believes that the USAF and NASA should cooperate when it comes to rocket design and acquisition. Yes, they have different needs, but in every way that saves taxpayers money, in every way that benefits the nation, cooperation should be an imperative. The one single thing I like that Gingrich has said is that he would make USAF and NASA sit down and do this.

We do not need a new HydroLox engine, we have a good variety now. We very much do need a new domestic high thrust, affordable, and efficient RP-1 engine. No, the government shouldn't build it; yes, the government should list the specifications and bid it. We need a KeroLox booster for SLS that could also fill the roll of AVP2 and be the first stage of an Orion launcher in a 1.5 architecture. No, the government should not build it; yes, the government should list the specifications and bid it. And, regardless of ULA/LocMart/Boeing/EELV red tape, it is in the interest of the nation to get over the turf wars and do this.

To the general public, all the inter-agency bickering and refusal to work toward a common good is just more evidence of bloated and ineffective government.  A robust science based space exploration program is in the interest of national security, and the USAF should appreciate that; the USAF has need of a higher number of launchers than NASA and NASA should make as much use the same hardware as possible; further, they should have access to any and all of that hardware. It is sad when really smart people do not come together and do what is best for the nation. It is part of the reason support for the space program has waned. This may seem naive to some, but many do feel this way.
« Last Edit: 04/09/2012 05:20 am by TomH »

Offline USFdon

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Re: SLS-a step forward or back to square one?
« Reply #36 on: 04/09/2012 05:37 am »
My perspective, as someone who is far removed from this industry, yet who has a deep interest in it, is that turf wars between government agencies is petty. The average citizen, no, let me make that the average taxpayer actually believes the FBI and CIA should cooperate in overlapping areas. The average taxpayer believes that the USAF and NASA should cooperate when it comes to rocket design and acquisition. Yes, they have different needs, but in every way that saves taxpayers money, in every way that benefits the nation, cooperation should be an imperative. The one single thing I like that Gingrich has said is that he would make USAF and NASA sit down and do this.

We do not need a new HydroLox engine, we have a good variety now. We very much do need a new domestic high thrust, affordable, and efficient RP-1 engine. No, the government shouldn't build it; yes, the government should list the specifications and bid it. We need a KeroLox booster for SLS that could also fill the roll of AVP2 and be the first stage of an Orion launcher in a 1.5 architecture. No, the government should not build it; yes, the government should list the specifications and bid it. And, regardless of ULA/LocMart/Boeing/EELV red tape, it is in the interest of the nation to get over the turf wars and do this.

To the general public, all the inter-agency bickering and refusal to work toward a common good is just more evidence of bloated and ineffective government.  A robust science based space exploration program is in the interest of national security, and the USAF should appreciate that; the USAF has need of a higher number of launchers than NASA and NASA should make as much use the same hardware as possible; further, they should have access to any and all of that hardware. It is sad when really smart people do not come together and do what is best for the nation. It is part of the reason support for the space program has waned. This may seem naive to some, but many do feel this way.

Totally agree with everything you say. My point is that the RS-25E/F and RS-68A, as time goes on, should "drift" towards a goal of progressive commonality (and eventually merge into one engine family). The USAF has made it perfectly clear that it will continue to support the $1 billion dollar a year fee to ULA to keep both the Atlas and Delta families operational to guarantee their access to space. By siting down with the USAF, NASA could hopefully sign some sort of MOU (or something) to develop something like the AVP2 as the SLS booster. This will get ULA its AVP2 and Nasa it's Kerolox booster. As for Delta IV, keep it as is and "drift it" towards a more cost effective platform (commonality with AVP2??, idk). Whether we like it or not, the US government will be in the launcher design and operation business for a long time. There is just too much pork at stake for congress to dispense to their districts.

If it were up to me.... (and hey I am an armchair rocket designer), how about an AVP2 strap on booster for SLS (using a domestic AJ26-500) which transitions into a stand alone booster for ULA and a man-rated Delta IV booster that can be used for NASA. Plenty of pork is spread around and NASA gets a cheaper booster to lift orion sooner (whether that is cheaper than Atlas Heavy or AVP2, that is out of my realm). Politically though, a Russian produced RD-180 is probably a no-go for NASA.

Offline Jason1701

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Re: SLS-a step forward or back to square one?
« Reply #37 on: 04/09/2012 08:55 am »
Still think that a combined USAF/NASA large hydrolox engine should be a goal for the future. Need to get those production numbers up.

No A hydrocarbon booster engine should be the goal

It is.

It might be.  The SLS Block 1A booster type is yet to be determined.  It could turn out to be an advanced solid. 

 - Ed Kyle

I was referring to USAF's Hydrocarbon Boost.

Offline clongton

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Re: SLS-a step forward or back to square one?
« Reply #38 on: 04/09/2012 09:22 am »
If it were up to me.... (and hey I am an armchair rocket designer), how about an AVP2 strap on booster for SLS (using a domestic AJ26-500) which transitions into a stand alone booster for ULA and a man-rated Delta IV booster that can be used for NASA. Plenty of pork is spread around and NASA gets a cheaper booster to lift orion sooner (whether that is cheaper than Atlas Heavy or AVP2, that is out of my realm). Politically though, a Russian produced RD-180 is probably a no-go for NASA.

My preference would be for a human-rated 4xRS-68 powered SLS core designed around a STS-like ET, assisted by 2 pair of AJ26-500 powered AVP2 LRB's, with the ability to add 1 or 2 more pairs of AVP2 boosters as the lift requirements dictated; very much AJAX-style Heavy Lift. Create a Centaur/WBC-style US/EDS powered by 4 to 6 Next-Gen RL-10's for those missions needing the added propulsive capability and upgrade all existing Upper Stages to use that engine. This HLV would lift 75 tonnes with 2 pairs of AJ26-500 LRB's in basic flight configuration and be approaching 140 tonnes with 4 pairs all without the US and considerably more with it. This provides the USGov with a lift capability starting at 75 tonnes and going up well past 140 tonnes and everywhere in between in a single LV. Any lift needs below 75 tonnes can fly on the D-IV or AV. Anybody claiming we need more than this kind of flexible capability is crazy.

The RS-68's would keep synergy with the D-IV, keeping the engine costs down for both D-IV and SLS, while the AV transitions away from the Russian RD-180 to the domestic AeroJet AJ26-500. The Atlas continues to serve the DoD and NASA roles it has been, while picking up the additional roles of SLS LRB and Commercial and Government Crew Launcher. The cost of existing US's would be kept down by sharing the RL-10's across all 3 platforms.

I can't imagine a more efficient use of American Government assets for USGov spaceflight needs.
« Last Edit: 04/09/2012 10:06 pm by clongton »
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Offline anonymous1138

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Re: SLS-a step forward or back to square one?
« Reply #39 on: 04/09/2012 11:22 am »
For instance (just one example), how many Atlas V launches would $20 billion buy? Rather, how many Atlas V launches would $5 billion buy, and what payloads could you develop with $10 billion? Would that extra $5 billion buy accelerated development and testing of an Atlas V Heavy? I would think so. Further, I'd call B$ on anyone who insists you need heavy lift (as defined by SLS) at all to do worthwhile BEO missions. The point is that SLS is an uncreative, old-school solution that only leverages "certain existing assets" (read into that what you will), when there are much more forward-thinking and *executable* ways to go.

It depends on the mission.  EELV and other launchers could support crewed lunar exploration, without SLS, but SLS in bunches is needed for crewed Mars flights.  Mars, not the Moon, is the goal.

 - Ed Kyle

My personal feeling is that Mars is *a* goal, but the real goal is much broader than that. And what is needed for the broader goal - a really thriving space economy - is going to be delayed or prevented by the cost of SLS. No, we don't need "SLS", specifically. What we will need at some point is the ability to lift lots of mass affordably. That's not SLS in any sense of the word, "affordable" if you look at the cost of development and operations that we have in front of us.

So, again, SLS may be a decent use of existing assets if what you yearn to do is to just build a Big Rocket, but if you want to move into space to stay, this approach is a step backwards.

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