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For Calliban re post about Lattice Confinement Fusion:
https://newmars.com/forums/viewtopic.ph … 59#p231959
That presentation is dense with information.
Hopefully the paper was well received and productive. There should be multiple follow up studies in the record.
In an attempt to distill the essence of the work reported, it ** seems ** that researchers found that by packing Deuterium into natural uranium or ? perhaps ? nuclear waste, the natural emission of neutrons ? may have caused some fusion events in the Deuterium, which ? may have generated more neutrons, with the ultimate result being heat that can be harnessed?
Update later after conversation with Gemini: It appears that the research to date has used titanium or erbium as the metal into which (or with which) Deuterium is bound. In addition, it appears that gamma rays are needed to create favorable conditions for fusion, and those are supplied by delivery of high energy electrons from an external source.
My question for you is whether there might be another source of the required gamma rays?
The Lattice Confinement topic is available for explanations if any exist.
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For Calliban re topic on Cast Basalt...
I just reread the topic from the top. It flows nicely, and contributions by fellow NewMars members seem to add to the topic without swerving too far from the main theme.
SpaceNut brought in the similar (but decidedly different) concept of the geodesic dome.
The link you provided to the Nissen hut led to a well constructed and maintained Wikipedia article on the huts designed in 1914 (or so) and then constructed ever since in various forms and various names.
A wedge shaped cast block might serve as a construction element to make arches.
The link below leads to a collection of images. Stone arches are included.
https://www.google.com/url?sa=i&url=htt … AdAAAAABAE
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For Calliban re progress with wind powered tumbler...
Thanks for showing us how well the project is coming along!
And thanks for the boost to the SMR topic as well.
I noticed an enrichment level of 3.8% or so in one of the posts that have appeared recently.
I assume any radioactive material is subject to restrictions, but isn't that a fairly low level of enrichment?
I ask because I would ** think ** that authorities would be more receptive to a nuclear proposal if the fuel grade is low.
In his post, kbd512 pointed out the amount of infrastructure that is still needed for an SMR even if the reactor itself is truck transportable.
I'd like to see atomic power advance as rapidly as possible.
My theory is similar to Calliban's (to the extent I understand his writings)....
The more energy a society has to harness, the better off the population will be, even taking inevitable inequality into account.
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For Calliban re report of underwater energy storage:
https://newmars.com/forums/viewtopic.ph … 73#p232173
Thank you for finding and posting this interesting report.
You have pointed out the use of equipment at the storage site.
My observation is the same as I have for the OTEC concept. The undersea energy storage concept has the distinct advantage that only electrons are moved from energy source to energy consumer.
The OTEC concept involved moving vast quantities of baryons to eke out a tiny amount of energy.
The energy storage system you have shown us provides effective energy storage and it does this by accepting electrons as input and returning electrons as output. I can't evaluate efficiency from just watching the video
To me it is evident that this is an effective system for energy storage. The estimate of 60 years service life is impressive.
If a member of the forum has time to pull statistics out of the video, I'd be interested in the quantity of energy that the example system can store. Inefficiency in translation of electricity to compressed air would show up as heating of the ocean in the vicinity of the storage device.
It seems to me the link you found might fit well into one of our compressed air storage topics as well.
Air will heat up as it is compressed, and that heat will move to the nearby ocean.
Air will cool as it is de-compressed by pulling water out of the enclosure.
My comments at this point are limited due to watching the video without being able to hear the narration, so there may have been answers to my questions in the narration.
What I ** think ** I saw was a system for storing energy by compressing air, using sea water as the working fluid.
Update: https://newmars.com/forums/viewtopic.php?id=10883
Above link points to a topic where this system might be a good fit.
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For Calliban re Habitat topic: http://newmars.com/forums/viewtopic.php … 40#p232240
The purpose of this note is to try to encourage you to continue developing your ideas. We (forum) might be able to entice a trained architect to contribute drawings or perhaps even designs.
The robots that will be building those hemisphere structures need instructions, and they need materials shaped in suitable ways that have been specified with precision.
The plumbing will need to be designed and installed with precision. Plumbing for this purpose might be inclusive of all fluids, including electricity and light.
Heating and air management subsystems are needed, and those must be specified with precision.
Doors, windows (if any) and air lock systems must be designed, manufactured and installed with precision.
It seems to me that many of the materials needed for the enterprise can be installed before humans even show up, as technology is advancing.
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For Calliban re Diamond saw stone cut technique for Mars domes:
https://newmars.com/forums/viewtopic.ph … 50#p232250
Thank you for this description of what could easily become a set of interwoven industries on Mars, with lifetimes of multiple generations.
The specializations would include scouting for suitable material, collecting rocks for a project, computer mediated cuts for desired shapes, storage of product for customer needs, transport to a work site, assembly with grouting (similar to brick laying on Earth), inspection and correction as needed, and a number of specialized skills similar to existing practice on Earth.
I do not know the answer to this question, so hope it might be of interest for a future post: Can laser beams cut basalt?
It would certainly be convenient of that is possible. The wear on the cutting blade would be zero, although some way of removing cuttings would be needed.
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For Calliban re post in Restaurant
https://newmars.com/forums/viewtopic.ph … 60#p232260
In the case of this particular restaurant, the variety of choices seems to me beyond the reach of a paper solution.
There is no (or low) risk you will be subject to this in the UK, but it is possible there may be someone who sets up a shop like this.
I'll post a link to the restaurant web site, and invite you and other NewMars members who might be interested to take a look.
When I first saw this I thought "nice web site" but didn't realize that ** was/is ** the menu.
The neighborhood where the restaurant is situated is a good match as well. Everyone has a smart phone, and likely an iPhone.
https://www.sowplated.com/
https://www.sowplated.com/menu-lunch/
The business has been running since 2019
It seems to me that a restaurant on this scale on Mars is a possibility for the distant future.
It is only a possibility on Earth after thousands of years of evolution, the Enlightenment shift from ignorance to science, and the development of a global supply chain with the levels of specialization required to enable universal smart phone distribution to the population.
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For Calliban re Void's idea of a Starship on it's side for a habitat...
Your description of strong outer walls made of compressed regolith or (my favorite) laser shaped rock/basalt creates a picture in my mind of a shelter with plenty of radiation protection into which an intact startship might be slipped/rolled (on rollers) so it could be adapted for use as a habitat/workspace.
** This ** post is an architectural question... Would it be worth considering to make the stone structure in the form of a cylinder, large enough so there is plenty of room around the Starship so Void's caution about placing anything against the side of the Starship could be honored?
I ask about the cylinder shape because that shape might be able to distribute force to the underlying regolith better than a simple arch would do, and a simple arch would have a flat bottom that would not be compatible with the cylindrical Starship.
Because you are one of the few NewMars members (you, GW Johnson and Void) who can create images, I am hoping you might have time to create drawings of such a combination. I'm hoping that at some point drawings can show important details such as plumbing, power supply and atmosphere management.
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For Calliban!
Thanks for letting us know of the trip to Sweden with Mrs. Calliban!
If we in NewMars are ** really ** lucky, we may get to see photographs of the visit.
I am particularly interested in the stone architecture, since you have described how it might work well on Mars!
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My wife and I took the sleeper train from Stockholm to Narvik. We had two nights in Narvik. It is not the most artistically beautiful town, but the natural scenery was inspiring. We were very lucky with the weather. We are in Kiruna for one night now and will be getting the sleeper train back to Stockholm tomorrow night. I will put photos on the website when I get back to UK at the end of the week.
"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."
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For Calliban re #260
Thanks for the update on your visit to Narvik, and other parts of Sweden!
Glad to hear the weather is holding!
The images you upload will be a welcome addition to the archive.
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For Calliban re images from Sweden and Norway...
Your comments about how a Mars settlement might be created to resemble the scenes you show us caused me to imagine an LED lit sky over head. While building such a sky scape might seem expensive in 2025 terms on Earth, it might turn out to be quite affordable in the time period when Mars settlement is under way. And such a sky would be something to behold. It could be programmed to deliver light of various colors from a default light blue to full night black with stars faithfully reproduced based upon the actual sky above that location on the planet.
No science fiction author that I can recall has ever had a vision that stunning, and that is probably just a reflection that science fiction writers are human beings whose imagination is influenced by their experiences on Earth in their era.
Thanks to your picture tour of Stockholm and other cities, the NewMars readers who chance across your topic will have an opportunity to stretch their imaginations beyond their existing extents.
Update:
I sent the link to a relative, and got this reply:
I was on the southern tip of Sweden for a day in 1974. I would love to visit Norway and have enjoyed watching travel programs it. I enjoyed looking at Mr. Calliban’s pictures.
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For Calliban re paper on "plutoids" ...
Thanks for that ** very ** interesting paper from ca 2013. It seems to me it holds up well, even though it was published before New Horizons arrived at Pluto.
Here is a snipped from the end that I thought NewMars readers might appreciate:
The colony can expand to contain millions of individuals, each capable of living a full and rich life. Indeed,
communications with Earth and other nearby colonies will allow them to be part of, and contribute to, the greater
human experience. Because the colonists have lived with Earth-normal gravity their entire lives, they are free to
return to Earth whenever, however, they can. But they will have their own world to care for and mange, one that
provides a home for much of Earth’s life, in many ways safer than Earth. This new home, with proper care and
maintenance, could last for many thousands, maybe even millions, of years.It may transpire that in the fullness of time such colonies become the norm. Each colony would be a technical and
artistic masterpiece of the human spirit. Living on an actual terrestrial planet under an open sky may become a thing
of legends, too risky to actually attempt. If things get too crowded, or if the urge for adventure becomes too great,
well, there is always a more distant plutoid.
ACKNOWLEDGEMENTSThe authors would like to thank Les Johnson of NASA, Kelvin Long of the British Interplanetary Society, the
reviewers who made the paper so much better, and the organizing committee and participants of the 2nd Tennessee
Valley Interstellar Workshop held in Huntsville, Alabama in February of 2013. What a great time.
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For Calliban re post about COPV ...
https://newmars.com/forums/viewtopic.ph … 92#p232692
The undersea vessel that imploded last year famously made popping sounds as it descended prior to the fatal descent.
If those popping sounds were individual fibers letting go, they could have been interpreted as a signal that the walls of the vessel were under severe strain. The lesson was not taken in that case.
In the present (SpaceX) application, the forces are exerted outward, but it seems to me an individual strand might let go before the entire assembly fails. In that case, having a microphone affixed to the exterior of the COPV might help to know when the vessel is under severe stress and likely to fail.
The time for that information to be relevant is during loading.
It's possible that a microphone would pick up sounds of loading that might overwhelm a popping strand signal.
We will probably never know when the SpaceX tank failure occurred. If it occurred during loading, the microphone monitor might be helpful. If the failure occurred some time ** after ** loading, the microphone might not give much warning in advance of the total failure.
From an operations point of view, we will probably never know how far the pressure was advanced with respect to the predicted strength of the material. If the intention was to store as much ? nitrogen ? as possible in as small a volume as possible, one way to discover the capacity of a tank is to push it to it's limits.
***
I like your vision of the unfolding of the future with settlements filling the Solar System in coming centuries.
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For Calliban re post about light water vs heavy water reactors...
It seems to me that as humans expand into the Solar System, they will be more likely to find natural Uranium than anything that Nature might have enriched.
if you were planning an expedition, and nuclear power is an option because some uranium is known to be present in the destination, I'm curious if you'd opt for enrichment as one pathway vs separating Deuterium from ordinary Protium. it seems to me that both will require specialized equipment, a supply of energy, and time for the work to be done.
It doesn't seem to me that one approach has a major advantage over the other, but I'm hoping you might be able to shed more light on the question.
Please continue working in the Fission Power topic.
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For post re fusion reactor size ...
https://newmars.com/forums/viewtopic.ph … 33#p232833
Thanks for this update, and for the details on scale.
One detail that I am curious about is how magnetic force scales...
My experience with magnetic repulsion is that the strength of a field falls off as the cube (It might be the cube root) ...
What ever it is, strength falls off more rapidly than gravity.
Will that be of concern as folks try to scale up reactor size?
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For Calliban re post on Tangent launch
https://newmars.com/forums/viewtopic.ph … 63#p232863
Thank you for your support of the Tangent launch proposal...
kbd512 first suggested this launch strategy some time ago, and I have lost track of the series of posts ... Recently GW Johnson re-discovered the concept while doing some studies of ellipses for various orbital mechanics situations. The disadvantage of such a launch strategy is the long flight through the atmosphere with all the consequences such as heating and noise. The ** big ** advantage (of course) is the savings of mass for oxidizer.
Your endorsement of the proposed 3 km acceleration track is particularly helpful. The water slowing method you suggested reminds me of test runs by Colonel John Paul Stapp MD. I did a quick lookup ... Colonel Stapp reached 632 mph in 3000 feet. That was one courageous individual! Google came up with two g force readings: 42.6 vs 46.2 ... Either one is remarkable.
It seems to me that your suggestion of a sled has those experiments in the 1950's as a practical example to study.
The maglev system would be expensive to build, but there might be advantages worth the expense. One advantage is reduced maintenance because shoes/sabot would not wear out.
From the article I get the impression a 1 km deceleration track would be achievable, since the carrier will be unencumbered.
Engineering to permit carrying of a heavy launch vehicle will be a step above what is required for a maglev train.
It might turn out that maglev technology cannot be pushed to that level.
In any case, this would be an exercise for engineering students that will remain attractive as an alternative to vertical launch.
This system might be particularly attractive for passenger service.
One of PhotonByte's models is a good fit for this scenario.
https://newmars.com/forums/viewtopic.ph … 46#p205246
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For Calliban re 1 bar atmosphere away from Earth...
There is quite a bit of conversation in the forum archives, about pressure needed to sustain human life when away from Earth.
A particular subset of that conversation is about situations such as Mars or in space craft.
In those situations, 1/2 bar atmosphere is the consensus view.
The situation you've described might be different, if there will never be a need for humans to venture outside into vacuum.
However, it seems to me worth considering 1/2 bar as the Norm for off-Earth habitats.
In that case, the pressure might obtain at lesser depths, than the depth suggested in a recent post in one of Void's topics.
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For Calliban re post about deflation in China...
https://newmars.com/forums/viewtopic.ph … 88#p232888
I haven't read the link you provided. I am responding to the word "deflation"
It seems to me that in a healthy economy, deflation would be the norm, as competing individuals and groups find ways to produce goods at ever lower costs.
The adjustment for inflation (as shown in the US) is to raise pensions (and wages) to compensate.
The adjustment for deflation would (it seems to me) be to adjust pensions and wages downward to match.
Eventually, as Startrek predicted, every material need humans might have will cost nothing.
The Sun produces enough energy to satisfy every material human need for eons.
Poverty is the condition we see when we humans don't understand how the Universe works, and fail to provide for each other.
Abundance occurs when enough humans understand the Universe, and enough cooperate (whether knowingly or not) to produce the goods and services everyone needs.
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For Calliban re deflation vs Inflation ...
Your observation/report of deflation in China inspired me to ask Google's Gemini to (at least try to) review the differences between inflation and deflation and why one is better than the other:
https://newmars.com/forums/viewtopic.ph … 97#p232897
My sense of this is that it (the two phenomena) are going to be present on Mars, so lessons learned on Earth will surely be helpful there.
In the case of China, Gemini reports high unemployment, especially among youth. That is hard for me to understand, because China is reported to have a robust system of education, and education ** should ** be the key to gainful employment. Perhaps the key here is the possibility that all the material needs of the population are already being satisfied, so there is no need for more workers in any of the established industries?
This would seem to me to be a ticking time bomb, because one time honored way to "employ" young people is to engage them in a war.
Another possibility is to surge out into space, where all that talent will spend it's energies doing whatever it takes to survive, let along establish new communities.
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For Calliban re inflation/deflation/China/space ...
The transcript at the link below takes up the question of possible surge into space.
Gemini seems to think the highly educated young people who are unemployed in China are ill prepared to tackle a surge into space.
It may be true. There is quite a stretch between a social worker an an engineer.
Still, having a strong education is a better place to start that would be the case without one. Aptitude for mathematics is something that needs to be nurtured from the earliest years, in order to mature into mastery in adulthood.
https://newmars.com/forums/viewtopic.ph … 98#p232898
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For Calliban re vertical launch first stage boost...
GW Johnson is starting to think about your scenario, in addition to others that are in focus right now. He did note that the full drag of the atmosphere will be in effect as the vehicle leaves the tube, compared to a typical 30,000 feet or so when second stages start.
That drag will decrease the benefit of the vertical launch.
Calculations should reveal the overall benefit. I'm looking forward to seeing them.
It occurs to me that your scenario deserves it's own topic. It is not a good fit for the existing three topics, which are complicated enough.
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For Calliban...
GW Johnson wrote an email about your question, combined with comments about various questions I had posed...
The bottom line seems to be a point that I had not thought of .... the vertical launch concept would provide about .3 km/s of the 8 needed for LEO.
The competing system is a traditional first stage. The cost of the tube system could be amortized over multiple launches, but meanwhile the traditional first stage would be launching and returning for re-use multiple times.
GW also takes up other launch ideas that are in play...
The email below includes some history that might be of interest to a few NewMars readers...
For transition, I had pointed out that Submarine Launched Ballistic Missiles are lifted above the surface with compressed air...
SLBM's are cold-gas ejected un-thrusted from their launch tubes at relatively low velocity, because of the immense drag of the water. There's just enough speed for the missile to pop up just above the surface, where the rocket ignites. From there the flight dynamics are identical to any vertical land launch.
My qualms about gun launch relate to orbital class speeds deep in the atmosphere. The drag and the aeroheating will be horrific! Unlike anything before encountered! That is in addition to the 20,000 gee-class of the gun acceleration. A standard naval 5-inch/54 gun is a 20,000 gee launch.
Vertical rocket launch is done at very ordinary gee levels as the propellant load burns off. Speed deep in the atmosphere is subsonic to about 10 km up, for rather low drag, and still somewhat-low supersonic drag in the thinner air of the stratosphere as the trajectory bends over significantly traversing the stratosphere. The thin air at 50-ish km keeps the drag low as you accelerate to low hypersonic speed (Mach 5-ish). That is fundamentally why vertical launch rockets are successful and operational, and most of the other schemes are not, except for air launch.
Using a vertical launch tube to reach Mach 1 at launch only reduces your rocket dV requirement by about 0.3 km/s, but the higher speed and drag lower down in the atmosphere probably adds at least that much drag loss to your rocket dV requirement! I don't see this as a very fruitful possibility. Why add the complexity and the capital investment for the launch tube, when you don't achieve any bigger payload fraction?
What air launch from a subsonic airplane provides is (1) horizontal takeoff and (2) thinner air at high altitudes for lower drag as the rocket accelerates from insignificant speed to hypersonic as it leaves the sensible atmosphere. This still requires a staged rocket, and it adds another huge difficulty: the launch airplane is flying near its service ceiling (something that all craft powered by any kind of airbreathing engines inherently have), and cannot pull up to a high trajectory angle without decelerating, stalling, and falling out of the sky. It can just barely fly horizontally. The rocket must have wings big enough to to pull up to that high trajectory angle, and they add a lot of inert mass to the first stage. That is why the air-launched Pegasus rocket had wings. And while operational, it has not been an economic success: you don't see very many Pegasus launches. Complexity like that costs, so does the big launch airplane, and the payloads are inherently very small.
For air launch, you simply cannot ever do SSTO with chemical propulsion, because you cannot afford to tote the inherently-necessary giant wings to space! But your launch aircraft might incorporate some rocket propulsion in addition to its airbreathing engines, so that the craft can pull up to a high trajectory angle just long enough to launch a non-winged rocket onto a gravity-turn ballistic trajectory to space. If the launch aircraft is subsonic, the rocket will probably have to be staged, since it must supply essentially all of the ~8 km/s dV.
If the aircraft is supersonic, that comes down by about 0.3 km/s for each Mach number of flight. But bear in mind that there was, is, and for some time to come will be, no gas turbine engine capable of routinely flying faster than about Mach 3, maybe 3.5 at most. That still puts 7-ish km/s dV on the rocket, at the very least. So you are probably looking at a staged rocket anyway. You have to get that down to something at or under ~ 6 km/s worth of dV requirement, to even consider a single stage. Lower still, if you want to use dense propellant fuel materials. They all have lower Isp with oxygen.
Building such a launch aircraft that can pull up to a high trajectory angle (in the vicinity of 45 degrees) while heavily loaded at high altitude is something that has never been done, but it could be! It takes mixed propulsion to do this: not some idiotic combined-cycle BS. You need your turbojets, but you also need some rocket engines. And you can't afford the inherent performance compromises by trying to combine them. Plus, controlling the launch aircraft successfully after it launches the rocket will be very difficult. But with mixed propulsion and attitude control thrusters, as were on the NF-104, something could indeed be designed to successfully do this job.
Economics? We would have to try it and see. But given the success of partially-reusable vertical-launch TSTO vehicles, I would anticipate few investors for a giant mixed-propulsion high-subsonic airplane carrying TSTO rockets of limited payload size. It's just the Pegasus problem, scaled up, and rearranged a little bit to get rid of the heavy wings on the rocket (has pull 4-8 gees to pull up rapidly). The large mixed-propulsion launch aircraft is a huge capital investment, no matter how you attempt to do it. Most airliners are designed to pull only 2.5 gees, probably enough, but risky done at full speed, even in the thin air.
Also be aware that there is a very good reason why supersonic store separation is not something the military does very much at all anymore, because the aerodynamic forces on the store exceed its weight, and cause a very high collision risk with the aircraft. So talking about a launch carrier aircraft that is supersonic is probably nonsense.
Why? I have seen multiple test videos of 500-lb bombs coming back up under wings, rolling outboard and up over the wingtip, then rolling back inboard on the top of the wing. They usually strike and damage the horizontal tail as they roll off the upper wing surface. That same sort of aerodynamic force-greater-than-weight thing caused a D-21 drone to collide with the modified SR-71 that launched it, killing one of the two crew in the launch plane.
This casualty caused the USAF and CIA to put an underslung big booster on the D-21 and launch it instead subsonic from B-52's. The D-21 was ramjet powered, with a takeover Mach just above 2.5, and a cruise Mach of 3. They were trying to launch it at its supersonic takeover speed from the modified SR-71.
I don't know where it would be appropriate, but if you want to post this exposition somewhere on the forums, go ahead.
GW
For Calliban ... I asked Google's Gemini to run a quick estimate of how much your proposal would improve performance of the SuperHeavy/Starship stack. It came back with a ballpark figure of 8 times greater mass to LEO. It reminded me that this value is high, because the Super Heavy would have to be strengthened to lift the greater mass above.
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