A Heavy Metal, Cannibalistic, Asteroid Propulsion System

Image courtesy Wikipedia

You’ve found the asteroid of your dreams. Ryugu, the asteroid recently visited by the Japanese probe Hayabusa2 has yielded up a hefty portion of its $83 billion dollar evaluation. Autonomous drones have harvested the low hanging fruit, stashed it in giant carbon nanotube nets, and are waiting for the asteroid to come near Earth again. They will then head back, towing the billions of dollars worth of palladium, cobalt, water, and some nickel and iron home to a safe orbit around the Earth or Moon. The drones are leaving a lot on the table, though. There is a mountain of iron, nickel, and cobalt left on the asteroid worth even more. 

The asteroid Ryugu

Surface of Ryugu

What if there was a relatively cheap way to get that as well? You could use mined water to make hydrogen and oxygen to burn in a rocket mounted to the surface of the asteroid. That, however, is expensive because water is one of the most valuable things in space in the early future history of asteroid mining. Instead, use the asteroid’s iron mass as a propellant to change the asteroid’s orbit so that it eventually is captured by Earth’s gravity and then slowed and parked in a Lagrange point. Here’s how it would work.

Plastic grocery bags prefer this as their second career.

One of the mining machines, specifically one that chews up elemental iron or anything else into small chips for hauling off is left on the asteroid along with some of the mined water and a few large packages representing a propulsion kit and automated delivery systems. Several general purpose assembly drones are also left on Ryugu with a special task assigned to them. 

They will take the propulsion kit, which includes an auto-controller and override, and assemble it into a coil gun mounted on the surface of the asteroid pointed in the general opposite direction of where the asteroid needs to go. It will be assumed that the rotation of the asteroid has been eliminated. There is a manual remote override for the propulsion system because some people on Earth are squeamish about machines guiding asteroids and have trust issues. 

Although the coil gun will be fixed, there will be conventional thrusters burning hydrogen and oxygen on a fixed boom (for leverage) that can rotate the asteroid (and the coil gun) to any point in the heavens. 

For simplicity we are going to base the coil gun on U.S. Navy experiments in constructing large coil gun weapons. They used a 15 meter long barrel with a 17 kg sabot shoving a 78 kg shell down a 30 cm inside diameter coil barrel. They used a 30 meter long barrel as well, but I’m sticking with the short barrel to cut down on heat generated. You’ll see why in a bit. The results show a velocity of 2.55 km/s. With just the sabot (the iron slug) alone and no non-magnetic payload, it should be a much greater velocity. By mass alone it should be 5 times faster. The ratio of magnetic material to nonmagnetic also goes from about 20 percent to 100 percent so the coils are acting on the entire load. That should be good for another factor of 3 with a commiserate scaling up of electrical energy. The velocity could be around 38.25 km/s. But let’s say we’re off by 50 percent to the up side. We’ll bring the velocity down to 19.125 km/s.

Use those plastic grocery bags again. Save money. Save the world. Here’s how. 

We are going to use a ball of iron chips about 250 mm in diameter for coil gun ammunition. The chips are put into a spherical mold, water is injected to fill the cavities, the whole thing is allowed to freeze and become a 180 kg ice ball of iron. The Navy rig back in 1993 was capable of firing 6 rounds per minute. Due to advances in technology, let’s make that 12 rounds per minute. Twelve rounds at 180 kg = 2160 kg. Divided by 60 seconds, that’s an average of 36 kg per second. Although water is a valuable commodity in space, the little amount used to glue the iron chips together is such an elegant solution to packaging, it makes it worthwhile. Now you see why generated heat is important. We don’t want this snowball to melt before it’s thrown. 

Force (thrust) = mass x velocity. Mass = 36 kg. Velocity = 19,125 m/s. Thrust = 688,500 N or approximately 155,000 lbs., which is twenty percent more than the largest commercial jet engine, the GE90 which set a world record of 127,900 lbs. of thrust. 

This may seem a minuscule engine compared to the estimated 450 million ton mass of Ryugu until you consider the gas tank contains upward of 400 million tons - about 1600 years worth. You would run out of water before iron. 

To reiterate, an automated breech delivery system gathers iron chips, injects them with water and freezes them into icy cannon balls. It delivers these via tubes or other conveyor system to the breech mechanism of the coil gun which fires these every five seconds into the void for propulsion. There is some history that verifies the validity of such a system. In the mid-1990s NASA did a study on a maglev launch system, StarTram, to launch unmanned craft into orbit. Its cost and feasibility was validated by Sandia National Laboratory, but it was, obviously, never implemented. It would have made the cost of getting things into orbit 100 times cheaper. 

Packbot 7, an ancestor of asteroid mining robots - NASA

This propulsion system could also have applications for turning an asteroid into a transit system going from near Earth to near Mars or the Asteroid Belt or other parts of the Solar System. As the iron chipping robots tunnel out more and more fuel, the habitat portion of the asteroid could become quite expansive. All or most of the interior of an asteroid devoted to habitation will have sufficient wall thickness between it and the exterior to block even the most severe galactic cosmic radiation. The mining robots could also be programmed to tunnel in geometric patterns amenable to being rotated about a central axis, providing the artificial gravity human travelers will find necessary to keep their bone density from becoming too low. 

Other articles you may enjoy:

Oumuamua: Alien Probe or Asteroid? It Could Be Both

Cryptocurrency Is Going Into Space

Going Back To the Moon Is Not Just for Governments Anymore

Why It Is a Certainty We Will Become a Space-Based Civilization

Asteroid Mining - How to Pick the Right Asteroid

Recycling Asteroids For Fun and Profit

Taking the 06-03-25 Asteroid Shuttle to Mars - An Alternative to Planned Mars Missions

Sticking the Landing On Your Billion Dollar Asteroid

Artificial Intelligence and Asteroid Mining Will Be a (Necessary) Match Made In the Heavens

The Weapon of Mass Destruction Nobody Is Talking About

How We Can Diminish the Possibility of Water Wars

There's An Asteroid Out There With All of Our Names On It

What Will Be the Most Common Currency In a Future Space-Based Society?

Workers In Space Will Live In Igloos

How We Will Get Asteroid Material Back To Earth

The Military Values High Ground - Space Is the Highest

Very Large Scale 3D Printing In Space

Energy and Space; Tweedle Dee and Tweedle Dum

China’s Strategy for the Future Is Scary Smart

We Will Live on the Moon: the How and Why

A New Age of Exploration

© Copyright Douglas Maas and licensed for 

reuse under this Creative Commons Licence.

Who hasn’t seen one of the google camera cars rolling down some street? I’ve seen them several times. I haven’t been able to make out if there is a driver in the car or not, but the camera is the thing--360 degree views everywhere it goes. It heralds a new age of exploration by proxy. According to this article, Explore the Amazon With Google Street View, you can even explore the rivers and jungles of Brazil.

This technology is ripe for maximization, and by that I mean minimization. It won’t be long before this technology is shrunk to fit on your body. It can be be worn while extreme off-road biking, diving the Great Barrier Reef, spelunking, climbing Mount Everest, New Orleans at Mardis Gras, the Burning Man Festival, a walk through a local park, or a night out dancing at a local music venue. It will be a wonderful means for people that can’t experience these things to vicariously participate, enriching their lives. No modern explorer would be without one.

With the purchase of your groceries and this device, you get free trash bags for life.

It can be attached to remote-controlled, even autonomous, drones cruising beneath the sea, through sky or jungle. Attached to a balloon, it could climb 100,000 feet to the edge of space. It could be incorporated into a satellite making a tour of the Solar System or the Asteroid Belt. It will be attached to Moon crawlers, Mars rovers, or robot subs on Europa. It will be a new age of adventure; one that everyone can participate in. It will be a new connectedness with our planet, our solar system, and our culture. Someone needs to do this.

Someone is. You know for a fact Google is working on it. We already have Google Earth, Google Moon and Google Mars. Also, Roy Ragsdale is doing his part in developing the technology. He explains how he made his own, off-the-shelf, street-view camera in this article DIY Street-View Camera. He’s already got it down to something you can wear while walking around. It’s an amazing article. I see a future where links on Google Maps or Google Earth take you directly to 360 degree videos of that particular geographic location. These will be in addition to what Street View gives you now on Google Maps. And we'll see them start popping up on YouTube.

Thanks to LexnGer

Although it's hard to believe there can be entertainment as good as Racoon Nation or Radioactive Wolves to be generated by someone walking around with a camera strapped to their torso, perhaps we can at least have something better than daytime TV or "Angel from Hell" to look forward to in our voyeuristic future. It may even inspire someone to go do something in person. So get crackin' Google and/or Roy Ragsdale on the helmet or pocket version of this great device.


Glen Hendrix, author Transmat World

Think, People, Think

Through the media we are bombarded by strife and the rumors of strife. Our leaders find it hard to focus on long term issues because of political turmoil, recessions, famine, nuclear proliferation, or civil wars. The very structure of our government and economy is such that problems are dealt with on an election by election or quarter by quarter basis, leaving little time for future planning. We seem to be in a constant state of flux. We should be doing better than this. We must do better than this.

Saving the world one bag at a time. This is recycling genius.

There are some that wax philosophical about the continued existence of the human race. They compare our existence to the dinosaurs and make the argument that all species have a “lifespan.” My argument is that we are smarter than the dinosaurs and, yet, it looks as though they will have lasted about 100,000 times as long as we will since their reign was 650 million years and it looks like our technological civilization is only going to make it about 6,500 years Okay, we don’t have armor, large teeth, tons of muscles, etc.; but we do have an obscenely large brain to weight ratio. Problem is we’re not using that for the long-range planning needed to give T-Rex a run for the money.

Except for the handrails near the top, this was a typical Earth scene for 160 million years. 

  © Copyright Hywel Williams and licensed for reuse under this Creative Commons Licence

If humankind insists on keeping all its eggs in one basket (staying on Earth), the universe is bound to make an omelette someday. Whether it be an asteroid strike, a spray of high-energy gamma rays, or a super volcano eruption, the results will be the same. Civilization will go back to a handful of survivors living at a primitive level of existence.

Asteroid Strike

We should be striving now to develop the technologies we need to protect the planet, go beyond our cozy envelope of air, and start extracting resources and energy from the Solar System at large. I’m not talking about further development of rockets. We’ve got enough products of combustion to deal with. We need to develop a space elevator. It is the only way to get significant loads into space cheaply and often. I describe a seriously practical scheme for one in my book Transmat World.

And I’m not talking about a colony on the Moon as our next space project as Newt suggests. Actually, the the prospect of harvesting helium-3 from the Moon could be lucrative but, in general, we want to avoid gravity wells. They are expensive and there are too many alternatives. The asteroid belt contains the material we need to thrive in space and it floats there, waiting to be harvested. We have the technology to capture these asteroids, bring them back to Earth, and sculpt them into space habitats after mining them for useful metals and minerals. These technologies are also described in more detail in Transmat World and other blog posts: The Space Mirror Hack, Asteroid to Habitat: The Transformation Begins, and The Space Egg.

Use those bags again. Save money. Save the world. Here's how.

We have to use our huge brain anomaly to consider the simple solutions for major problems that could arise. For instance, a nuclear winter has several possible causes that have nothing to do with war. It can also be caused by volcanoes or an asteroid hit, making it one of the more likely doomsday scenarios. The weather conspires to destroy crops for several years in a row causing billions of people to starve. The solution? The emergency mushroom kit. Mushrooms, a good source of protein, can grow in very little light making it the perfect go-to crop for this disaster. Has anyone investigated the viability of this simple solution? Do our governments have mushroom spores for the multitude stored in vaults along with the Ark of the Covenant? Very doubtful, but it could be a simple, inexpensive thing that would save billions of lives if the worst happens.

Could mushrooms be the go-to crop?

  © Copyright Pam Brophy and licensed for reuse under thisCreative Commons Licence

This is the simple, mindful type of technology we need to be thinking of and developing for the future of mankind here on the planet and beyond the confines of Earth; a future that is not stark and limiting but boundless and full of energy and promise. So start thinking.


Thanks for your time. My name is Glen Hendrix and I invite you to comment on this blog.

The Combustion Trap

by Glen Hendrix


There is a science fiction novel, Transmat World, that mentions "The Combustion Trap". It is the name of a theory wherein all civilizations go through the same process. The discovery of fire and its gradual increase in utilization to the point of planetary ruin before the civilization realizes it is even in trouble. In the book it is a theory put forth by an alien robot thousands of years in the past; but, in reality, it is a serious subject that political leaders and scientists ignore at the peril of the future of humanity.

Image courtesy of Alun Salt under a Creative Commons License.

The atmosphere has been in equilibrium, more or less, for millions of years except for the great extinctions that wiped out most of life on the planet due to volcanic upheavals or comet/asteroid collisions. It has always recovered. For the next extinction, we are going to have to come up with a work-around for two reasons: 1. We are causing it. 2. We don't want to be extinct.

Image courtesy of Incompetech.com and Kevin MacLeod under a Creative Commons License

Sometime between 200,000 and 800,000 years ago humans began starting fires on purpose for cooking, or warmth, or security, or all of the above. It was one of man’s overarching achievements, making possible his technological advance while at the same time, possibly, sealing his doom. The giant mechanisms of equilibrium used by Earth for millions of years just shrugged off these tiny flames in the dark and went about their business for hundreds of thousands of years.

Image courtesy of blvesboy under a Creative Commons License

Then in the late 1700’s James Watt invented the steam engine and the Industrial Revolution began. Now just the carbon dioxide from human combustion activities is 130-150 times what is produced from volcanoes every year. With huge populations of China, India, and other countries driving consumer economies, demanding goods on a par with the United States, the products of combustion will continue to rise until, inevitably, the ancient and reliable mechanisms of equilibrium falter and the climate begins to change to a point where the Earth becomes uninhabitable. The next great extinction will occur, taking mankind and a good portion of the current animal and plant life with it.

It shouldn't take an alien robot in a science fiction book to tell us what we already know. After millions of years of relative climate stability, we are introducing more products of combustion than volcanoes into the atmosphere every year with no end in sight. Unless we can alter our behavior on a societal level, it's very likely our children or grandchildren will feel the extreme effects of global warming. It is a bad situation but not a hopeless one.

Reuse those plastic grocery bags. Save money. Save the world. Here’s how. 

There are many scientists who think the Earth’s mechanisms of climate stability will be able to withstand any onslaught mankind can offer. I hope they are right, but I don't think they are. If you look at it logically, human civilization is the slow super volcano, the glacially paced asteroid strike. Because it happens so slowly, it gives ephemeral beings such as humans a chance to deny it. This won’t prevent their ancestors from cursing their stupidity. The Earth’s climate has been changed radically five times in the past, causing extinctions, and it is radically changing a sixth; this time in slow motion. Some would argue that it's not even that slow. This article from Scientific American describes a Stanford University study that claims over the next century climate will change 10 times faster than it has in the past 65 million years.

It's my contention this is the very reason aliens aren’t knocking at our Solar System door (besides the enormous gulfs of time and space). Every intelligent, self-aware, land-based, oxygen atmosphere species that arises in the universe goes through the same Combustion Trap. It begins with the discovery that fire can be controlled and, because life is short, there is no serious thought given to what might happen beyond one’s lifetime. Before the newborn civilization can get into space it finds itself in the same dilemma as the human race.

Let's say the skeptics are right. What if the Earth would be going through these changes without the meddling of man. What if there is going to be another Ice Age no matter what we do and global warming will only act to ameliorate that? Is it worth all the work and expense to understand and change, if necessary, the climate of our planet? Let's examine the possibilities and the stakes: 1. We spend a lot of time and treasure and discover the truth and a solution. We live. 2. We spend a lot of time and treasure and discover the truth but no solution. We die. 3. We do nothing. It turns out to be a tempest in a teapot. We live. 4. We do nothing. Climate change is real and the enemy is us. We die. Since when did smart humans depend on the roll of dice or flip of coin? We don't have an option to do nothing. It should be noted that as time goes on without doing anything the solutions must become more heroic and more expensive.

Collectively, we have the foresight acuity of a mole but individually we are pretty eagle-eyed. Our individual creativity will save us. If we have to, we will figure out how to terraform our own planet or to such CO2 from the air and use it or store it. If we are to get out of this mess, technology and astute leadership will be our saving grace. We should call on our leaders to do something instead of nothing. They can provide incentives. We can invent our way out of the Combustion Trap. We will control the climate. We will use the sun's energy. We will harness the atom safely. We will spread into space and it will become our second home. We will explore and mine and study the asteroids and moons and planets. We will do these things because we are human and that is our destiny. We must fight the good fight and be victorious, if not for ourselves then our children and all who come after.