All posts by Robert Smith

SSI Supermodels (part 2): Make your own SSI Mass Driver

[looking for part 1 – the O’Neill Cylinder Model?  click here!]

In the early 1980s, Dr. Richard Woodbridge III, a Princeton graduate and retired Vice-President of the New York Life Insurance Company was SSI’s Executive Vice President. The SSI Conference Proceedings and SSI Update Newsletter Archives document much of Dr. Woodbridge’s excellent volunteer work for the Institute, but one little thing he did seems to have stuck in the minds of many long-time SSI Associates: The 3 page paper “How To Make A Model Mass Driver.”

Mass Driver Model page 1
Mass Driver Model project page 1


This short document gave everyone with a little extra weekend time the hands-on experience and personal pride of building a conceptual model of one of the most important engineering aspects of The High Frontier Concept.

The SSI Mass Driver is *THE* mechanism to cost effectively launch the raw materials that make those huge SSI Space Manufacturing Facilities, Island Colonies and civilization-changing Solar Power Satellites.

The biggest restriction to such HUGE engineering projects is the cost of lifting the dumb mass of their infrastructures – not the high tech parts, those add up to only a small percentage of the total weight and established rocket technologies can handle that – it’s the dumb support structures that can not be lifted economically from the surface of the Earth. But lifting the raw mass from the surface of the Moon or from Asteroids is a totally different cost structure… when you add the simplicity of the Mass Driver technology.

This small model is a very low powered concept project. It dosn’t have any photoelectric beam detection to automatically turn on the switch as the driver is coming near – a series of these and timing to alternate the currents to provide pull and push forces at the proper moments is how you get the huge speeds in short runs. And this model running at your house doesn’t have the vacuum or the low temperatures that make the Mag-Lev guide system of a real Mass Driver as amazingly efficient. But it IS a working model of the coil pull part of the equation.

It’s a thought starter, great for anyone who has been looking for a jump start warm up project to get the wheels turning on Space Manufacturing and it’s excellent for kids in grades 5-12 looking for a unique Science Fair presentation. Plus, as I found when making mine for the video, it’s just plain fun.

You can just watch the video on the SSI YouTube Channel but to get the full picture you should take the few minutes to read the text of the original paper below; It adds extra enhancements that can make your model a bit more exciting than the one I made for demonstration.

By the way, after seeing that pre-wound spools of 18-20 gauge wire weren’t being wound as accurately as companies had done in the past, I got actual original Radio Shack wire spools on Amazon for just a few bucks, and Home Depot sold me the doorbell button for a penny. In all, the cost was about ten dollars and I did the whole thing in about ten minutes (including the time spent swearing about burning the insulation near the solder point – D’OH!)




A mass driver has four parts:

1. The MASS that shoots out into space.
2. The DRIVER that pushes the mass out and then stays behind to be used again.
3. The ENERGIZING COILS that make the driver move, and
4. The ELECTRICITY, in our model from a battery, which moves through the energizing coils turning them into a magnet which draws the driver into the inside of the coils, pushing the mass, then stopping the driver. The mass shoots out into space.

Space Studies Institute Make It Yourself Mass Driver image 1

Space Studies Institute make it yourself Mass Driver image 2


The MASS. Use a small piece of wood from a wooden match, or toothpick, or twig. Or a small brass screws. That is – something that is not iron or magnetic.

The DRIVER. This must be of iron like a piece iron rod and it must be thin enough to fit inside the plastice drinking straw. A Number 6 or Number 8 Finishing nail works well. A Finishing Nail is a nail with hardly any head.

The ENERGIZING COILS. You can get from a store that sells electronic parts HOOK-UP WIRE that is wound on a hollow plastic core. Get from Radio Shack a spool of No. 18 gauge hook-up wire, 55 feet, stranded. One end of the coil is free on the outside. The other end of the coil sticks out into the inside of the spool. So, you have an energizing coil right there. Scrape the insulation off each wire about a half an inch. This may be tricky for the end that sticks out into the hollow core is short.

The ELECTRICITY. Use a 6 volt lantern battery.

The PLASTIC DRINKING STRAW. You can get from your grocery store (and many other stores). Whatever you get needs to be about 1/4 an inch in diameter and smooth inside.

The SWITCH. At your hardware store get a doorbell button.


Connect the wires as shown. Put the drinking straw through the spool of wire as near the center as you can. you can pack tissue or modeling putty around the straw to hold it in place. Put in the piece of match stick (which is the MASS), and then put in the nail behind it just so the head end slightly enters the coils.

Press the switch and hold it down a second. The DRIVER will be drawn into the coil. The MASS will fly out the other end. The DRIVER will stay behind.

You have made a mass driver! Not very spectacular, but is is a mass driver.


To make the mass driver more powerful add another 6 volt battery, that is, in series, the plus of one battery to the minus of the other.

A word about what is happening. Do you remember where it is said to hold the switch down for a second? Well, if you let the switch up too soon the coil cannot stop the DRIVER and the DRIVER will shoot out. That is because thie coil does not have the time to draw the DRIVER back before the electricity is turned off.

Also, if you happen to lift the switch, that is stop the electricity just as the DRIVER is being drawn back, the DRIVER may shoot out the back of the tube. So, WARNING, do not get in front of the mass driver. Do not get in back of the mass driver. And do not let anyone else!


If you cannot for some reason get a hold of the inside end of the coil there are two choices, unwind the coil, get the other end, and rewind it on the same spool, or better yet, though it is fairly hard to do, wind you own coil. If you do wind you own coil then you can have a much more powerful mass driver!


The idea is simple, make the wire of the coils much closer to the drinking straw. You could wind the wire right on the drinking straw, but that is very hard to do because the drinking straw is not very strong.

It is best to wind the wire on a piece of a wooden dowel, 1/4 inch in diameter. This wil give you a coil with a center hole (after pulling the dowel out) into which you can slide on the drinking straw. Make the new coil about two inches long and wind all 55 feet on it. The sounds easy, but it is not. It is best to think of rolling the wire on the dowel by turning the dowel and unrolling the wire from the spool.

As you wind, try to keep each winding touching the one before it. You will find that the windings tend to separate one from another and fall apart, stick them together using pieces of tape sticky pieces you can cut off the ends of plastic Band-Aids. you can also use a piece of this sticky tape to fix the wire on the dowel when you start winding. Finish by coating several times with clear nail polish.


WIRE: Can use Bell Wire (from your hardware store) or 20 gauge hook-up wire.
WINDING: Can wind coil on a wooden pencil. A No. 2 of No.3.
BATTERY: Can use a 10 volt lantern battery.
IDEAS: Make scenery for the mass driver, like on the surface of the Moon or Mars or put out in space with the stars. You can set things up so that a little light flashes on when the switch is turned on, Use your imagination.


Battery – 6 volt lantern battery. Hardware store. $8.40
Wire – Spool of Hook-Up Wire, 18 gauge, stranded, 55 feet. From Radio Shack $2.19
Switch – Doorbell button. Hardware store. $2.40

Copyright 1986 by Richard G. Woodbridge III


fyi: we have recently found a trove of photographs of the making of the original SSI and SSI/MIT Mass Drivers. We’ll be releasing those in a special way soon. Also, there are a LOT of MD related items in the SSI Newsletter Archives including one issue from Summer 1980 where Gerry dedicates a whole article to details that will make perfect sense to anyone  who has made their own simple working model.

Energy. And Power.

Heinlein correctly said at the end of Have Spacesuit Will Travel that there is no “Luck”:

“Why were you on that frequency? Because you were wearing a space suit. Why were you wearing it? Because you were determined to space. When a space ship called, you answered. If that is luck, then it is luck every time a batter hits a ball, Kip, ‘good luck’ follows careful preparation; ‘bad luck’ comes from sloppiness.”


Ever have one of those days when it seems every direction you look you’re being hit over the head by the same message in a different form?

For the past few days I’ve been working on the webification of the Q1 1996 SSI Update for the SSI Newsletter archives (thanks to SSI Senior Associate Robert Sugg for sending in his clean copy), this issue is a bit more time consuming to html-ize than most because of the number of Math and Greek symbols in the text of the main article (“Sling Launch Of Materials Into Space”).

Anyway, I had finished that article and was moving on to the “Power From Space: The Imperatives Of Commercialization” by Mary Woodell and just to have some media in the background I switched on the Roku to the Great Courses channel. I had recently purchased the course “The Science of Energy: Resources and Power Explained” by Professor Michael Wysession, Ph.D., but hadn’t had the time to watch it.

This course IS great, it does an excellent job at making the fundamentals of the economics, historical patterns and the science completely understandable to an educated, but not insider, audience.

The thing about it though is that it has so many Elephant-in-the-room moments. At so many times Wysession gets right up to the lip of mentioning Space Based Solar Power – I mean, right… to… the… lip – but then doesn’t take the step. And it doesn’t seem to be out of any Buck Rogers fear, because even in the very first lecture he takes a journey through Space to Mars and talks about the energy requirements for the trip and a Mars colony; Later he does a very nice reverse life story of energy to show the incredible inefficiencies of established energy products by starting from electric lamp in a house, back to the production plant, back through the mining/drilling, back through organisms that died to make petroleum and coal, back through the layers of atmosphere and back to the Sun.

Ugh! There was the perfect place to mention that avoiding all the hundreds of millions of years of middlemen is possible with SPS, but he doesn’t… take… the… step.

I was yelling at the TV.

I’m hoping that later in the course he’ll do the right thing at least to cover all of the bases, it is 24 30 minute lectures and I’ve only finished the first handful so there is time.  I like to go in order to appreciate the flow, and I do see that Lecture 23 is called “Probable and Possible Future Energy Sources” so maybe, maybe.

But here’s the point, in an early lecture just as he was saying:

“I think humans are a remarkable species and I don’t want us to take the chance that our human experience on this planet could come to an end because we took energy for granted and allowed our infrastructures to collapse. But public opinions matter and the views of people can greatly affect our energy decisions.”

… I was transcribing this paragraph from Mary Woodell:

We must recognize that, as with any technology, successful commercialization of WPT [Wireless Power Transmission] depends first on public acceptance, which then can be parlayed into market demand. Without acceptance, there will be no demand; and, in a free-market economy, without demand there can be no product. In short, broad public acceptance is a minimum requirement for successful commercial application.

The timing of this and other lineups was creepy ;-). But of course it wasn’t completely random coincidence, both the article and the lectures were generally about energy needs and the past 20 (30? 40?) years of limited changes in the power industry couldn’t make them differ all that much. The growing needs, declining resources and widening gaps between classes that The Club of Rome and Limits to Growth dropped like a bomb on the world – and that O’Neill and Glaser and Brown and their students offered options for – are hitting the mainstream hard now…  just as The High Frontier said that they would be doing.

So what can we do? Our friends at the NSS are righty very proud to let everyone know that SPS was – once again – brought to the leaders of the United States Government. SPS is called one of the top techs to work on – for ‘someone’ to work on. That’s good news – once again. But it’s not great if the population takes that news bite as meaning it’s all done and they can stop thinking about it – once again.

Along with the technical minutia that many of us can spout off in our sleep (and sometimes put people to sleep with at dinner parties), it’s important to have an understanding of how to put and keep the “Regular Sally and Common Joe” in the loop and actively interested so it doesn’t – yeah, once again – fall by the wayside.

I hope you’ll check out the article by Mary Woodel in the Q1 1996 SSI Update for some non-engineering information that may help us boost awareness of the actual, do-able benefits offered by Solar Power Satellites, and also ask you to consider checking out the Great Courses offering “The Science of Energy: Resources and Power Explained” to see how those currently outside of the SPS area are looking at the big picture, trying to learn the fundamentals and searching for solutions. A source of points from today and a source of considerations from 1996 can add together to make us better prepared for those impromptu conversations and on stage presentations about the SPS pillar of The High Frontier.


August 30th addendum: Remember, on the SSI YouTube Channel there is the Solar Power Satellite Roundtable video from the first International Space University sessions at MIT.  Peter Glaser, Bill Brown, Professor O’Neill and Makoto Nagatomo all together presenting the concepts and details of Space Based Solar Power technology.  Click here to watch it now.

SSI Supermodels (part 1)


With summer coming to an end and vacations over it’s time to find things close to home to keep the kids (or grandkids) occupied. How about an O’Neill Colony that’s easy to put together and makes The Vision a physical reality that you can see from all angles … on a desktop scale?

Long ago SSI paid thousands of dollars and waited months for a rather large Bernal Sphere model to take to conferences, alas that model was lost to the past (and as I hear tell, it was a pain to move from place to place) but right now for just about the cost of a video game your family can have an O’Neill Cylinder that you can put on any shelf  or take with you to meetings.

This model from the Wave company in Japan was created for fans of the Anime series Mobile Suit Gundam 00 (which has no relation to the annoying song, “MSG” is a multi-season series set in a future where SSI Colonies and Solar Power Satellites – and giant mechs – are part of normal life).

This is a near-perfect Island for engineers and budding engineers to display.  Plus, it’s really easy to put together. Technically, it just snaps together so careful fingers and a fingernail file to gently smooth the little nubs down is all you need.

Here’re a few images to hopefully get you interested:

1) The box. See, it’s an O’Neill.

Wave company Space Settlement O'Neill Colony model box
Wave company Space Settlement O’Neill Colony model box


2) The cool special booklet showing details of the “real thing” It’s in Japanese, but pretty obvious.

Neat booklet on colony details
Neat booklet on colony details

Booklet second image

3) After carefuly removing the parts from the marked pieces frames (they are all numbered to make it easy), you just apply the stickers that show the interior valleys and snap them to the end caps.

The Colony Valleys
The Colony Valleys are nice stickers


3 take 2) Oops, the instructions say to snap the three windows in first, that helps the valley parts sit better between the windows.

Colony model windows
Best to put the windows in first


4) After carefully applying the mirror stickers, just snap the mirrors to the end cap. (Do be careful applying the mirror stickers, on my first one I didn’t slow down and line the sticker up perfectly then tried to peel the sticker off to re-set it and so I’ve got a crumple that won’t smooth out. Taking a bit more care on the other two worked better)

Adding the mirrors
Adding the mirrors


5) Slide the end cap covers over the end caps and the mirrors lock into place, meaning no glue is required and all of a sudden the model is very secure.

Now  just slide in the metal bar, slip that into the base, then pop on the agriculture ring and the service module and… voila!


Now, when I was trying to get the ag-ring pieces separated from the pieces frame I accidentally broke part of the ring (you might notice it sagging a bit at the top near the support strut).  So I drove over to the local Michael’s Crafts store to get a tube of model glue to fix it.

That trip not only fixed the break but also gave a fun story – and some interesting research:

While I was at the model section of the store there was a young man about 13 or 14 going through the paints and he asked me what I was working on. I told him it was a space colony which made him give me a quizzical look… so I said “the Space Colony from Mobile Suit Gundham” and he said “Ooh, nice!” I think that’s an interesting piece of information for folks who may be looking for a common-ground way of starting a discussion of The High Frontier concepts with younger generations.

But back to the model, I mentioned to the kid that I was lousy with a paint brush and asked if he had an easy tip to help me bring out the embossed detail on the model. His advice was to buy a small bottle of dark grey or black Testors model paint and a few cheap brushes, dip a brush into the paint then wipe it off on a paper towel so that almost no mark is left on the towel then brush the model with this “dry brush.”

I think I left too much of the paint on the brush … but still, it seemed to be a great tip!


The Wave Space Settlements O’Neill Colony model is available from sellers on eBay and Amazon. I’ve found the Amazon sellers tend to have a much better price, I paid all of 35 dollars including shipping from Japan and  I see them going for 60 on eBay.

Here’s a link to one of the Amazon listings (there are a few, actually) the seller I bought from was Toy Shop Japan Hobbyone, and I bought a second one for a gift from seller Makimono – both of them came in about a week, no problems at all.

Oh, my bad, you always use the Amazon Smile Program to make your purchases benefit The Space Studies Institute, so use this link for Amazon Smile:

By the way, if you came to this post after googling for Sports Illustrated Supermodels, I do apologize ;-).   And if you’re wondering why this post is titled “part 1″… come back in a day or so to get the instructions for a make-it-yourself working SSI Mass Driver. Yes, I’m serious. This is one that might spur your kids to consider a really cool Science Fair project this year!

High Frontier giveaway results are in

This note comes a little late as I was in DC the past few days for SSI (more on that to come soon).

We want all SSI Associates to know that we’ve added up the worldwide free units from our Apollo 11 Anniversary week High Frontier Kindle edition giveaway and over 1700 (1742 to be exact) new Kindle copies are now in the hands of readers.

Added to the copies from the first giveaway, back when SSI had just released the Kindle Edition, that makes around 6500 in total that we have given away for free.  And remember, because Kindle lets a person only claim one copy per account for all time instead of allowing any “loading up” of extra copies that can take away from the reality of the numbers – these 6500 represent actual individual readers (on top of the thousands who buy The High Frontier Kindle Edition at the regular low price).

Many thanks to everyone who helped spread the word about the giveaway, and now that the book is in your Kindle libraries, don’t just let it sit there, take the next step:  READ the High Frontier.

We look forward to hearing your opinions and reviews and – we truly mean this – seeing what tangible things you are inspired to work on and share with fellow SSI Associates that will prove that The High Frontier is more than just a good book.  Let us all see where it takes you and how you are an active and real part of The Human Breakout Into Space.