Perfectly stated. But most people don’t get it. Most people have never been employed in a giant highly technical project. The NewSpace movement and it’s libertarian ideology is proof of that.

In my view we need to spend 7% on space again because it holds the key to the future of humankind. Nobody can deny we are slowly consuming the natural resources of this planet and decimating the number of species in our ecosystem. Consider Earth as just a larger Easter Island. It is popular to dismiss such “70’s hippie tree-hugging” with examples of failed predictions of doom and gloom. But I see megafauna on land and life in the ocean diminishing. That is the warning flag. The population continues to climb with sub-Saharan Africans on track to become the most populous ethnic group in the history of the human race. Gerard K. O’Neill understood that space was the place to go for unlimited lebensraum.

Space Solar Energy can be had exactly the way Dr. Spudis’ describes- in incremental steps. In my view those steps begin with humans-in-GEO telecom industry and the nuclear deterrent relocated to space, and then with factories on the Moon making pulse engines that can lift immense solar power stations from the lunar surface. It might take close to a century but once it is done…..we will be on our way. Those solar power stations in GEO can also power beam propelled launch vehicles and effect the holy grail of single stage to orbit airliners to space. Then we will be on our way to ever greater accomplishments.

Again, I am sorry Marcel but….it-is-a-lower-gravity-environment-and-will-be-deleterious.

Humans thrive in 1G and near sea level radiation and air pressure and deviating from that standard will be problematic. Living on Mars or any other body in the solar system would be a bad deal.

Living on a Bernal Sphere in orbit around the sun leading or trailing Earth would allow easy travel from one sphere to another and back home- to Earth.

Zubrin and then Musk garnered support from emoting sci-fi fans with very little understanding of the actual reality of what it takes for an independent population to survive independent of Earth. It is a scam.

Actually, the Moon is the place to “mine” for a century to come at least. I don’t know how many Bernal Spheres, each one several miles in diameter, could be built before some kind of problem with stealing material from the Moon would develop. Thousands or a couple of orders of magnitude more depending on how big the Spheres are.

The logical end of O’Neill’s colonization concept was a string of thousands of (or more) Bernal spheres trailing and leading Earth in orbit around the sun until the entire human race lived in space and the Earth was a place to visit on vacation.

Calling them “Orion Spaceships” is not really an accurate or even a good thing to do. Project Orion ended long ago and many are quick to ridicule it and associate bizarre impracticality with that name. I prefer “bomb propelled” simply because it is blunt and honest and will lead to acceptance of the concept that much sooner.

As for SRB’s…..truly humongous monolithic boosters were test fired in the 60’s and such monsters could lift mind boggling payloads off of the Moon. But with lunar factories manufacturing alloy plates as Nuclear Pulse Propulsion engines any chemical rocket would be uneconomical compared to bomb propulsion. Breeder reactors on a “Nuclear Moon” would provide bomb grade material for centuries until a superior system (perhaps black hole starships) is devised.

Older folks can voice their political views quite effectively to government leaders. Older individuals often fully understand wise investments because of their own hard gained personal experiences. Our elders should not and cannot be ignored.

A population projection I looked at a few decades ago suggested that the USA could end up with the largest population of any nation on our planet.

However, lately I have started to doubt all population projections. Human lifespan extending technological changes are often difficult to fully evaluate and no one seems to be capable of estimating how many AI android folks are likely to be built each year.

Note:

“Researchers at Harvard Medical School and the University of New South Wales (UNSW) have uncovered one of the key mechanisms that gradually weakens our body’s ability to repair DNA, and tests were able to restore the cell function of old mice to that of their younger counterparts. The team says an anti-aging drug could be developed in the next few years, and the treatment also shows promise in reversing DNA damage caused by radiation exposure – good news for cancer battlers or space travelers.”

From: ‘DNA-repairing drug could fight aging and radiation damage’
By Michael Irving March 23, 2017
At: http://newatlas.com/dna-repairing-drug-nmn/48584/?li_source=LI&li_medium=default-widget

As our Home Planet starts to look seriously crowded, then extensively mining and industrializing the Moon and making full use of Cislunar Space to reduce pollution on Earth may begin to look like a politically and environmentally smart path to most folks.

Building lots of O’Neill Cylinders and other super sized habitats in Cislunar Space and putting them in orbits around the Moon, Vesta, Ceres, Mars, Neptune, and other large masses of rock and ice in space could seem both doable and useful to many folks on the Home Planet.

And as a practical security matter for our ever more crowded Earth, the increasing number of humans and AI android folks we have living off our Home Planet means our ability of seeing and the diverting or destroying large incoming NEOs should continue to improve.

Individuals and families of both youngsters and old folks and everyone of in between ages will eventually become more willing to invest in terraforming the Moon and eventually Mars and Venus.

Will all the spacefaring individuals or families want to live their whole lives on the Moon, or Mercury, or an asteroid, or in some type of enormous space habitat?

Probably not.

Many or maybe even most spacefaring folks will want to wander.

Economical mobility across deep space, like economical mobility on Earth, can greatly enlarge each individual’s and family’s perspective about what is doable, useful, and exciting in our Solar System.

Slowly but surely, more and more individuals and families and groups will travel to and live and work on the Moon for many diverse reasons and similarly some of those folks may also eventually spend decades working and living in an O’Neill Cylinder, or on Mercury, Mars, Ceres, Vesta, or Pluto due to various reasons, hopes, or dreams.

Efficient and safe future space transportation systems and long lives mean that individuals and families and groups of folks could decide to wander across our Solar System for many decades.

As a practical near-term matter, we will probably be mostly busy with the Moon and developing Cislunar Space for quite a few decades.

Nonetheless, if we want to avoid having our Home Planet’s space policies from being repeatedly hijacked by some folks with a strange and limited ‘Mars is the answer’ tunnel vision, we had best keep reminding ourselves and everyone else what was noted by Jan Wörner:

“We think that the Moon is a very important step. Mars is not the ultimate goal; humans will go further than Mars.”

“One benefit: Space colonies would be immune to Earthly natural disasters. ‘In the colonies there would be no earthquakes, no hurricanes, no tsunamis, no volcanoes,’ Stone says. ‘Plus, you pretty much control the weather in an O’Neill cylinder.’”

And, “As O’Neill wrote in Physics Today in 1974: ‘I believe we have now reached the point where we can, if we so choose, build new habitats far more comfortable, productive and attractive than is most of Earth.’”

From: ‘How We Could Actually Build a Space Colony’
By Adam Hadhazy 10/2/2014
At: http://www.popularmechanics.com/space/deep-space/a11351/how-we-could-actually-build-a-space-colony-17268252/

Mining Mars to build O’Neill Cylinders and structures like the Stanford Torus might be doable, but mining the Moon, Vesta, and Ceres seems to be easier and more useful in the near future.

During this century far more billionaires would most likely prefer the convenience of vacationing or living in an O’Neill Cylinder in a high Home Planet orbit or a high Lunar orbit than they would vacationing or living in an O’Neill Cylinder orbiting the far distant, cold, inhospitable, and inconvenient Red Planet.

Time will tell.

Currently, Orion spaceships powered by Nuclear Pulse Propulsion systems of various types seem workable and needed for reducing the risks, costs, and flight times for missions beyond Cislunar Space.

And while large and reusable pressure fed boosters would be useful and are needed, I expect SRBs may have useful ongoing roles not only for launches from the Home Planet, but also for launching large amounts of material from the Moon.

Why?

Because aluminum and oxygen are abundant on the Moon and could be used in solid propellants for large rocket sleds that could safely launch both humans and cargo to Lunar escape velocity.

Fourteen years ago a solid rocket powered sled set a 6,416 mph or 10,325 km hour or 2.868 km/second speed record on the Home Planet.

Escape velocity from Earth is 11.186 km/second.

Escape velocity from Mars is 5.027 km/second.

Escape velocity from the Moon is only 2.38 km/second.

Escape velocity from Ceres is only 0.51 km/second.

Escape velocity from Vesta is only 0.36 km/second.

Various types of electromagnetic launch systems could also be useful on the Moon and elsewhere.

Diverse redundancy in our space transportation and other systems is useful and avoids the issues of narrow and over specialized mono-systems that are prone to catastrophic failure modes that could collapse our options to only living on Earth.

Humans have the strength offered by the wide diversity in their capabilities, interests, economies, and engineering solutions to various problems. If we are wise, we will maintain that diversity and avoid the dangerous illusion of dogmatic perfection as we move out to live across our Solar System.

Since no one has ever stayed on the surface of the Moon or Mars for even a week– we simply do not know if it deleterious.

The gravity on the Moon or Mars could be harmful or it might not be harmful. We simply don’t know!

And we also don’t know if strenuous exercise could alleviate any problems associated with a low gravity environment. But we do need to find out!

And NASA should have found out if a low gravity environment was deleterious to humans on the lunar surface– decades ago.

Marcel

Note:

“An analysis of radiation safety issues on lunar lava tubes has been performed by considering radiation from galactic cosmic rays (GCR) and Solar Particle Events (SPE) interacting with the lunar surface, modeled as a regolith layer and rock. The chemical composition has been chosen as typical of the lunar regions where the largest number of lava tube candidates are found.”

And, “No significant differences in the results have been observed between the Lunar Night and the Lunar Day scenarios. After 6 m of depth, no effects of radiation due to or induced by GCRs are observable in the simulation, and after far less than 1 m no effects of radiation due to or induced by SPE particles are observable. Natural and induced radioactivity seems not to play a significant role in the lava tube exposures.”

From: ‘Lunar Lava Tube Radiation Safety Analysis’ By GIOVANNI DE ANGELIS, J. W. WILSON, M. S. CLOWDSLEY, J. E. NEALY, D. H. HUMES, and J. M. CLEM 2002
At: http://jrr.oxfordjournals.org/content/43/supplement/S41.full.pdf

Protection from galactic cosmic rays will normally be a critical issue for spacefaring folks. Massive amounts of shielding of various types could be used.

And, if building large rotating structures to provide artificial gravity in space is a useful and workable engineering solution, then running high speed trains in one mile diameter circles is also quite doable and useful for some of the many places in our Solar System that lack near Earth like gravity.

Venus might eventually be terraformed, but that could take several centuries…

In the meantime, and for most places in our Solar System, circling or rotating artificial gravity machines of various sizes and types are possible and likely to be built.

“‘The Roads Must Roll’ is a 1940 science fiction short story by American writer Robert A. Heinlein. It was selected for The Science Fiction Hall of Fame, Volume One, 1929–1964 anthology in 1970.[1]

The story is set in the near future, when ‘roadtowns’ (wide rapidly moving passenger platforms similar to moving sidewalks, but reaching speeds of 100 mph) have replaced highways and railways as the dominant transportation method in the United States.”

From: ‘The Roads Must Roll’ Wikipedia
At: https://en.wikipedia.org/wiki/The_Roads_Must_Roll

Could such a moving ‘roadtown’ be built and run in a one mile diameter circle? Sure it could. Is it an optimal artificial gravity engineering solution for some future off-world situations? Maybe.

Large rotating O’Neill Cylinders and structures like the Stanford Torus can produce artificial gravity and could be quite useful across our Solar System. However, other types of rotating, or circling, structures or machines may also have useful artificial gravity capabilities for keeping spacefaring humans healthy, happy, and productive.

Building artificial worlds with 1G is not much more difficult than living on Mars. This was the conclusion of Gerard K. O’Neill in the 1970’s and nothing has changed. Well, one thing has; we now know all the physiological problems caused by microgravity and this only supports his conclusion.

I predict the Moon will facilitate developing nuclear propelled spaceships which will lead to bypassing Mars completely in favor of Ceres and then the ocean moons of the gas giants.

This “analogy of spaceflight to seafaring” has never impressed me, nor do many analogies concerning space seem to be very applicable. Space is different than anything on Earth. However….

In my view astronauts will have to wrap themselves in a 15 foot deep “ocean” of water for any long duration missions Beyond Low Earth Orbit (BLEO). There is great resistance to this stipulation, and even outrage and shocked denial. But cosmic radiation is what it is.

Concerning re-fueling stations inside the Earth’s magnetosphere, in the “cislunar sea” between the Earth and the Moon, chemical propulsion is the only option. However, Beyond Earth and Lunar Orbit (BELO) the opposite holds true as chemical propulsion is useless. To push the required massive water shield there is really only one option: Nuclear Pulse Propulsion (H-bombs). This also inspires outrage and shocked denial when put forward as “the inflexible path.” But there is certainly plenty of bomb grade fissionable material available and so- it is what it is.

Lunar water is the stock to make fuel for chemical propulsion, and as I have related in past comments, using the volatiles trapped in lunar ice, methane might be a better choice than hydrogen. Water is also the fuel, all by itself, for use in pulse propulsion. For those unfamiliar with the concept, a specially designed bomb directing most of the energy in one direction converts a “slug” of material (or water) into a cloud of plasma which then pushes the plate or sail of the spaceship.

The idea of dosing and debilitating astronauts on long “chemical missions” distresses me and does have a nautical analogy as in trying to paddle a tree bark canoe across the North Atlantic. In my view only nuclear energy can take humans to the outer solar system. The first pulse propelled spaceships, because it may take decades before alloy plates of the necessary size are available in space, may resort to the Medusa spinnaker type of “soft” system. This “sail” actually does connect with the spaceflight to seafaring analogy.