Space-Based Solar Power

a public discussion sponsored by the Space Frontier Foundation

The Goal for 2050 and the Build Forward

Posted by Coyote on August 7, 2007

Enthusiasts and Skeptics,

To give you a basis for analysis, by 2050 the goal is to have forty or so concentrator-photovoltaic space-based solar power (SBSP) satellites in geostationary orbit, each broadcasting via microwave between 2-5 gigawatts of power to terrestrial electrical power grids, with 1-to-5 broadcast antennas that can beam power to as many locations.

This must be done using a sound business case. John Mankins calculates that this can be achieved by keeping the costs of delivery and assembly on orbit below $3,500 per kilogram–keeping the cost to customers below $0.10 per kilowatt/hour. This will drive robotic assembly and tug systems to pull these enormous structures from low orbits to geostationary. On orbit fueling stations will be required. Paul Werbos believes the best way to do this is to get launch costs down below $200 per kilogram.  But several other factors help make the business case. For example, if the price of other energy sources goes up it helps to close the business case for SBSP. Other factors include the efficiencies associated with solar collectors, energy conversion, antennas/rectennas, signal path loss, etc. Dennis Wingo and others have suggested that the first customers for space-based solar power will be international–in areas such as India and Japan where the price per kilowatt/hour is astronomical compared to the Americas or Europe. All of this goes into making the business case.

There will also be times when space-based solar power becomes priceless. When the Tsunami crushed the Pacific rim, when Hurricane Katrina flattened America’s Gulf Coast, and when United Nations forces responded to the beleaguered Darfur region the value of simply broadcasting power immeidately to the relief efforts would have been priceless in assisting the salvation of countless lives and facilitated the more immediate recovery of these disaster torn regions.

Keep in mind American and Allied forces operating inside Iraq. Convoying petroleum through the streets of Iraqi cities is a large source of casualties…and the electrical power plants that convert that petroleum into electricity are under frequent attack…and the lights go out…and the people aren’t happy. As I’ve mentioned before, one of our defense analysts calculated that the U.S. is paying between $300-to-$800 per gallon for fuel delivered to the Iraqi electric plants. Mike Hornetschek reports that 70% of all logistics movements inside Iraq is petroleum.

Inside Iraq, at this very moment–where people are dying–a supply of space-based solar power would have that priceless quality. And this is true wherever military forces and others are engaged not only in combat, but in nation building, humanitarian relief, disaster response, etc, etc, etc.

The question was posed to me today, “What does the military need.” Here goes:

According to Mike Hornitschek, a military base inside the United States consumes approximately 10 megawatts of electrical power. Forward military base overseas are consuming approximately 5 megaWatts of electrical power.

I need space-based solar power satellites of the 5 megawatt class. Let’s say by 2015. This capability will transform our logistics and reduce our vulnerabilities. The development of this class of space-based solar power satellite is designed to deliver that priceless quality of energy. Best of all, it can be done with current technology using current spacelift vehicles. Think about that.

But most important of all, developing the 5 megawatt class of satellite gets the ball rolling towards the 2050 vision that started this discussion. We WILL learn a great deal and we WILL find new efficiencies. We may make huge adjustments in the trade spaces as detailed in a previous discusion, and must be prepared to do so. In pressing ahead to field a 5 megawatt system, we will also be building the space industrial base and developing the rquisite spacefaring infrastructure to make the business case for the 2050 vision all the more viable.

There will likely be cities or regional utilities that will want to buy their own 5 megawatt satellite (or larger) as a backup, which will help the business case even more and give us a better look at problems that lie waiting for us as we build bigger systems.

The goal, then, for 2020 would be building/fielding a 10 megawatt system…1 gigawatt sytem by 2030…2-5 gigawatt system by 2040…on the way to fielding 40 2-5 gigawatt systems by 2050 as described above.

All the while the drive must be towards commercializing this effort at the earliest possible time. Energy must move at the speed and price established by free markets, not by government bureaucracy. To that end, I am working with Ed Morris and Mike Beavin at the Department of Commerce-Office of Space Commericalization to make this happen.

Your thoughts???


52 Responses to “The Goal for 2050 and the Build Forward”

  1. N. Rothman said

    Why not just do DR. Bussards Fusion?


  2. Trey Boudreau said

    Just a couple of observations:

    1) You need storage on the ground for that power. A honking lot of batteries, ultra-capacitors, or something. At least you’d have plenty of security to guard it 🙂
    2) Exactly how does a five megawatt SBSP satellite differ from a five megawatt directed microwave energy weapon? Having two-in-one seems useful, from a particular point of view.

    The notion of using it for troop support opens up a realm of possibilities.

    — Trey

  3. Brian Wang said

    The Ram accelerator, launch gun (chemical version of the magnetic launch systems)

    8000+ m/s launch velocity, 1400 kg+ gets to a calculated $500/kg

    $7 million for validation to orbital velocities
    $50 million for a gun that could launch to LEO
    $157 million for a BFG that might launch at $500/kg

    A hardened payload infrastructure would transition support by any future magnetic launch systems.

  4. Michael said

    How does the option of space-based transmission from terrestrial power sources fit in? If it reduces the cost of the system further, the case becomes stronger. And even if a space-based solar power system can’t be piggybacked on it later, the lessons learned in getting the transmission system to work will probably be needed in getting the solar system to work.

  5. Coyote said

    N Rothman: Fusion would be a fabulous option…except any mention of fissile material going to orbit triggers a firestorm of protests, controversy, and other mayhem. Fission or fusion reactors going up would take that to the Nth degree.

    Trey Boudreau: There would be some modest power storage requirements, but the goal is to provide baseload power. As for the weapon potential, take a look at my other postings on this site. We are looking for a safe, desaturated microwave power beam that has no weapons potential. In addition, one of out objectives is to stimulate the development of these systems in the commercial market. The DoD does not want to operate them. The DoD just wants to be a customer of safe, clean energy that can be beamed anywhere it operates.

    Brian Wang: You know, we really need to take a look at some radical launch proposals like this. The business case would really benefit from from a disruptive breakthrough (or two).


  6. Luna-tic&rockrat said

    N. Rothman:
    Dr. Bussards fusion process has alot of promise if he gets funding to validate his claims, He developed the procees and did all the R of (R&D) under navy contract. With a smallish buget of 25 million he says he could recreate WB-6 and with 200 Million he clains he could build WB-100MW an Aneutronic Fusion reactor.

    (the best part of his proposal economicly is that if doesn’t work after 5 years and the 1st quarter Billion you stop funding it, unlike the Tokamaks which are money sinks and have a guarenteed 50 year wait at mutiple billion dollars)

    Bussard published a paper on the application of his IEF design to rocket engines, his design at its worst is comparable to NTR’s whith none of long duration radiation.

    Trey Boudreau:
    multi-megawatt lasers or microwave weapons are “limited” why not simply use that energy to move a small mass very fast in the right direction?

  7. Trey Boudreau said

    Because for the cost of reloading you can put another bird into orbit.

  8. Charles F. Radley said

    For the 5 MW base, what is the physical size of the base? Can it secure a 1 kilometer diameter area? This is the size needed for a microwave rectenna.

    The rectenna can be deployed above the base.

  9. Phil Chapman said

    Don’t neglect the potential of thermionic conversion using carbon-based nanostructures (including artificial diamond). For more info, see “Analysis of a Diamond-Based Solar-Thermionic Power Generation System,” P. Majsztrik and T. Fisher, 8th AIAA/ASME Joint Thermophysics and Heat Transfer Conference, St. Louis, Missouri, June 24-26, 2002, available at

    These devices offer conversion efficiencies up to 80% of the Carnot efficiency (as compared with maybe 40% of the Carnot efficiency for conventional heat engines). For use in space, where the sink must be a radiator, minimizing mass probably leads to an overall efficiency of 25% to 30%.

    Maintaining the required cathode temperature (c. 1100 C) requires a concentration ratio >100, which means that 99% of the collector area can be lightweight reflective film, The devices are very radiation resistant, offering long life in GEO and the possibility of assembling the sunsat in LEO and then using its own power to move it relatively slowly through the Van Allen belts to GEO.


  10. Dan Lantz said

    Thru the late 70’s, the 80’s, 90’s and on, I went to numerous Mars manned program plan meetings, happening to be in one of the right places. Two problems with Mars visit, long weightlessness and radiation exposure, could only be solved with use of lunar resource: for large, heavy ship that would supply gravity (is centripetal acceleration artificial?) and shielding. Not a popular position to take, at the time.
    I also went to a few space station (under various monikers) meetings, hoping that a large, heavy structure could be built from lunar resource. It could then be free of the very expensive need to be both light AND safe, and have more capability.
    At some point, it becomes/will become obvious that it is time to invest in starting to use lunar resources for heavy, dumb things like shielding, simple structure, simple wire, Oxygen, H (if present)…
    At a later point, it will be obvious that we should have started sooner!
    Notice that many of the needs of various plans are met with single set of lunar resources, so the cost is spread out. Help those who want to go to Mars get there more quickly!
    Use of exoterrestrial resource begins an exponential growth pattern, while launch from surface is linear growth pattern, with limits of supply to boot.
    What are the estimates, under the stated 2050 goal, of when this investment in use of lunar resource is to start? If there are none, think about it!

  11. Brian Wang said

    The aneutronic fusion programs that have been funded are colliding beam fusion (Trialpha energy, $50 million or so from Venrock, Paul Allen and Goldman Sachs). They mentioned a timeline of 8-15 years.

    The Focus fusion project got about $2 million from Chili.

    The Z-pinch fusion has gotten indirect support as part of the overall Z-pinch work for nuclear weapons research. Recently demonstrated a repeatable firing capability which seems like it could be developed for fusion power. Need Dept of Energy or someone to step up and fund the separate work. Z pinch successes also enable mini-mag Orion launch system, which can be sub-critical (Andrew Space working on it). Billion degree temperatures in theory might allow aneutronic fusion. Minimag Orion has far lower performance criteria than for fusion.

    My favorite radical launch proposals are laser arrays with mirrors I think they would work and have the improving enabling technology trends helping make them better and better.
    Magnetic launch and the ram accelerator are next.
    Nuclear variants are also there because I know the tech would work, but would involve clear minds in the decision making/funding process. Probably have to be proved out beyond orbit first.
    Tethers and nanomaterials and other enhanced materials should be considered too.

  12. Edawg said

    If a company accept a dod grant does that exempt them from foreign national capital later on?

  13. allen said

    I’d be more optimistic about SPSS if the prospect of making big bucks were more apparent. As it is, any business case is necessarily filled with great, big unknowns which makes projections nothing more then an exercise in wishful thinking. Without the offsetting attraction of unknown but “they better be” very large profits all you’ve got is a high-risk, very large investment with no historical precedent by which risks can be gauged.

    Don’t get me wrong, I’m a “to go where no man has gone before” kind of guy but the engine of exploration down through history has been the prospect of obscenely large profits. If that prospect is anywhere to be found in the development of SPSS then I don’t see it.

    In fact, the dearth of accessible profit-making opportunities has bedeviled space development since day one. To the best of my knowledge the only profitable space enterprise is communications with nothing else even worth discussion until fairly recently.

    I’m referring to Richard Branson’s proposed super-rollercoaster which I think is just the precursor to a more viable space enterprise: passenger traffic. It’s a business Branson is very familiar with so the unknowns are offset by lots of parallel experience.

    Taking the morning Virgin Galactic Spaceship Three from JFK to Paris won’t be quite the same thing as taking the Concorde but it’s liable to appeal to a similar clientèle – people who have the means and need to buy the fastest way from here to there.

    If Branson’s making beau coup bucks he’ll attract competitors and there’s nothing all that exotic about Spaceship One and White Knight. I’m sure Boeing, Mitsubishi, Airbus or Mikoyan-Gorevich are capable of producing competitive designs once there’s a reason to do so. You could probably draw a price-passenger traffic graph with a couple of bits of information.

    Once you’ve got rockets zipping all over the globe and the magic of competition starts to take hold, prices come down to the point that all sorts of previously-ridiculous ideas start making sense. The Orbital Hilton? Zero-g manufacturing? All that stuff. Now you’ve got an industrial base upon which to plan even less-likely projects among which I would put SPSS.

  14. Regan said

    Air Force Secretary to DARPA: Free Us from the Oil Cartels:

    It seems that the more and more in the Defense Department are becoming more dialed in to the concept of looking beyond our current energy sources and truly diversifying.

    “I need space-based solar power satellites of the 5 megawatt class. Let’s say by 2015. This capability will transform our logistics and reduce our vulnerabilities. The development of this class of space-based solar power satellite is designed to deliver that priceless quality of energy. Best of all, it can be done with current technology using current spacelift vehicles. Think about that.”

    I assume that the base requirement for this early capability is in the receiving of power from an external source and that this would not be limited to transmission from a space-based asset but conceivably from any source as long as its vulnerability is limited, at least 5 MWe, and the need for major logistics is reduced?

    Also, do you foresee any future DoD SBIR solicitations involving key aspects of the technologies needed to field WPT and SBSP?

  15. N. Rothman said

    Hello Coyote
    nice website 🙂

    Dr Bussard needs $5m to validate the two experiments and work out some engineering issues. If it would not work at this stage of course he should not get further funding.

    America is going to have monopoly on Fusion and SSP in future. But today you must get Iraqi oil on world market […]

    America now has spent $1tr on Iraq and the Iraqi oil is worth $25tr. And this petroleum MUST!!! get on market. Because we have reached peak oil due to globalization and a ever increasing thirst for energy from emerging markets (China/India).

    But I think its good for America to get a real energy plan for the future so America can defend against OPEC/Global/Russia/Venezuela. Focus on getting Iraqs oil and have robust plans and funding for SSP/Fusion/Americas own coal.

    N. Rothman

  16. Luna-tic&rockrat said

    Trey Boudreau:

    Space Based Weapons Systems are not the topic of discussion, peaceful development of SBSP is. You pointed out the power delivery systems (Microwave/Laser) can be potentially weaponized. Let me point out that the damage is much greater if an energy source is used to electrically accelerate a projectile up to high velocity.

    First you need to realize that a launch system like the one Brian Wang describes (1400 kg moving @ 8000+ m/s) has about 11 tons of TNT in kinetic energy (which is comparable to the smallest nuclear weapons or the MOAB).

    Compared to Microwave or lasers which are great for non-hardened targets, Kinetic weapons are far more dangerous because they can kill hardened targets.

    looking up comparable electic weapons systems (the Navy’s prototype 64 mega-joule ship-mounted Railgun) a system with Brian Wang’s specs would have a projectile 77 times heavier moving 3 times faster with something like 1500 times the energy a shot.

    as bad as gigawatt lasers/masers could be, projectiles with the impact force of small nuclear weapons are worse.

  17. Des Emery said

    After the lift-off of Endeavour up to the ISS I think I’ve changed my mind about ‘rockets’ as long as the infrastructure of each SBSP station can be optimized (I really sound like a business geek now) to require as little as possible servicing upon completion. In space there should be no weathering of equipment, no winds or ice to knock down towers, no day-to-day maintenance. A one-time expensive launch could be amortized over many more years, making the long-term cost reasonable.

  18. An analysis like this is mostly just talk unless it can be backed up by a design study showing that the 5 MW power satellites suggested are feasible. As a general thing, space solar power concepts scale poorly to low power levels, because of diffraction-limited beam spread.

    Also, Hurricane Katrina would have wiped out any rectenna array. Beaming power to the disaster site with no receivers in place would have been pointless. (And, in any case, the distribution lines were down; even if you did have rectennas to receive the power, it would not have been usable). If you’re talking about having helicopters airlift in rectennas to provide power, there are a lot of other things that are being airlifted in, you’ll have to get in line behind food and medical supplies, and you’re no longer talking “cheap” here.

  19. Simple.
    SBSP requires low cost launch to orbit. The only way to get low cost launch to orbit is a very high volume market. FAA’s 2007 COMSTAC commercial launch projections (Table 1 at

    shows declining commercial launch over the next ten years. No prospect of massive launch to orbit from any quarter. Do YOU see massive launch to orbit growth in the decades ahead?

    Does Tailpipe Johnny Dingell’s Department of Commerce – Office of Space Commercialization – see massive launch growth?

    The only commercial prospect with the requisite volume and suppressed demand is SBSP. That won’t happen unless Congress charters Sunsat Corp – see chapter 10 at
    and Geoff is right.

  20. Joe said

    The time frames need to be compressed into a Path-to-Profitability of 8-15 Years.

  21. John Strickland said

    The most important point we need to make to the political structure is to stress the link between low cost and reliable access to LEO, and cheap clean Energy. No cheap access, no Juice.

    The best argument that we have to attempt to prove that SBSP cam become economically viable is the airplane argument: How much would an airplane ticket NY to LA cost if the airplane had to be built to carry passengers on its very first flight safely and then be thrown away?

    To answer some questions, and to re-inforce some of coyote’s points, Base Load is the minimum power you need per day. You do NOT need to store this power if the source is continuous. It is the need to store power for Ground based alternates that kills many of them, when the peak demand does not co-incide with the peak power availability.

    A rectenna structure, since it has little wind resistance, could be made relatively resistant to hurricane force winds, unlike ground solar or wind, which both present vulnerable solid surfaces of tubine blade or collector to the wind.

    My guess is that a 10-fold reduction in launch costs would make us relatively equal to the costs of ground based solar, which needs massive storage capacity.

    A good argument for SPS and for rectennas is that they are both made of a few kinds of identical parts, so they can be built or repaired concurrently, unlike standard power plants, which have to be built sequentially.

    Another advantage for the rectenna is that its sheer size means that a single point attack would take out very little of it – you would need massive bombing with shrapnel or nukes to take one out quickly, yet since it is simply a structure with metal antennas, it could be replaced quickly and inexpensively.

    I strongly support Fusion and other energy research, but we cannot count on Fusion for which no blueprint for a commercial fusion plant exists now or is likely to exist for decades in the future.

    Magnetic launch and Space Elevator are reasonable alternatives to rockets and hypersonics for which research should be supported.

  22. Joe said

    Space Solar power structures do not cost $100 Billion dollars. This is 1970’s technology.

  23. Dr. Welburne D. Johnson, II, MD said

    I’ll never forget the SSI conference where Peter Glaser and staff powered a helicopter with a 6 foot rotorspan using beamed microwave energy in a lecture hall at Princeton Univ.

    The military has a much more informed appreciation of “Peak Oil” and the crippling of military maneuvers. We will soon confront what is known as the ‘Export Land’ paradox. This paradox implies that there will be no net world oil exports due to the decline in production and the increased use of oil in the majority of oil exporters by 2016.

    All techniques of space solar power need reevaluation including Dr. David Criswell’s Lunar Solar Power system.

    LSP benefits include:

    1) no fear, however irrational, of reentry of massive structures striking the earth.
    2) stable base and use of in-situ materials for some, if not most, of construction needs.
    3) in an energy challenged world, LSP is the only justification that will allow taxpayer support for the V.S.E. I have had many arguments with Dr. David Livingston of The Space Show on this point. Additionally, it must be remembered that the maiden flight of the Orion occurs the same year that the Social Security surplus begins its terminal decline.

    Virulent ignorance pervades “vox popili” and a human spaceflight program will have to deliver tangible benefits.

  24. Peter J. Schubert said

    NASA has plans to go to the moon, and is currently funding in-situ resource utilization studies for factories which produce 10 or more times their own weight in useful raw materials. Oxygen is the first priority, with silicon next in line. Silicon is 21% of lunar soil, and can be used to make solar cells. I have 2 patents on means to extract silicon from regolith, and have published this at 2 space conferences.

    Transporting lunar solar cells to GEO can be accomplished with electromagnetic catapault launching within iron canisters, and electromagnetic receiving on-orbit. These receivers need a lot of power, and must be able to station-keep, a task that can be accomplished with laser ablation of slag from the silicon extraction process, and shipped with the solar cells. I hold patents on EM receiving on-orbit, and on laser ablation for station-keeping, and have published research on the former at a space conference this summer.

    An economic study of SSP using lunar solar cells shipped to GEO was published at SpaceEx 05, and indicates baseline electricity on-orbit at 0.16 USD/kWh after 5 years amortization. Transmission costs were not calculated. Although this is not very competitive with current US power costs today, it represents a considerable improvement compared to other approaches to SSP.

    Launch costs of the factory were taken at 110,000 USD/kg to a lunar pole; and these costs drive the economics. Because the factory produces more than its weight in raw materials, improvements in launch costs have additional leverage.

    I realize there are many engineering hurdles in such an architecture. However, it appears to have the greatest long-term advantages for terrestrial power, for in-space power, for a self-sustaining lunar settlement, and for future missions to Mars and the asteroids. I just completed a NASA Phase I SBIR on the oxygen extraction portion of this, and await Phase II approval. I’ve had students sponsored by the Space Grant Consortiums in IN and IL performing some of the other research.

    I am very interested to learn of others working on topics which could support such an architecture. Your feedback and comments on this posting are also welcome.

  25. Bluebird said

    Between now and the 40 satellites in 2050, Dr. Yoshiaki Ohkami (JAMSS, Japan Manned Space systems Corporation; e-mail: 2000, simple, as uncomplicated as possible, concept demos–maybe within next 10 years?

    Let the int’l collaboration begin.

  26. Joe Russo said


    I hope everyone is well

    Being back with the group is nice after relocating to another part of the country for a job promotion. Here are my thoughts on the proposal to construct 40 solar power satellites.

    I skimmed over The Goal for 2050 and Build Forward and see that things are shaping up real nice. The factual, objective focus is great, as the defense analyst shows. The use of the word priceless is also very good.

    Other points:

    Less Hostile Politics: I believe this document in question reflects more facts and critical thinking while not lighting the wrong fuse.

    Nuclear Power: As we discuss natural disasters, such as Katrina, in relation to this topic, I think we also have the opportunity to reflect on a more recent event (earthquake) in Japan that created a leak in one of the world’s largest nuclear power plants. Solar power infrastructure would eliminate this problem.

    Life vs. Money: The idea that life is priceless, mentioned in relation to natural disasters, is good. In addition, I believe that since society now cares so much about the lives of its military people, this might be the ideal time to ask the public to put its words to work. Solving the problem of oil dependence and ending the fight for certain resources might dramatically reduce costs. Thus, since money might be a gravitational factor with the potential to kill our efforts, we could also make the argument that a person’s life should not have a monetary value associated with it. The life vs. money argument might help insulate our case from competing cost factors.

    Money: I think the statistical figures showing how much oil is involved with the logistics makes a stronger case.

    Power Outages in Iraq: I believe this is a weaker point. No matter what power system is put in place, terrorists do not want light at night so that they can go around setting up bombs without being detected. As many military experts know, and as my engineering counter parts in the Army Corp of Engineers claim, our enemies constitute one main segment involved in the utility dispute (who is doing the damaging or not), as they want to be able to do bad things and upset others that we are present. Many sectors of the media do not present all the facts of you is disrupting the power system. Even with a solar power infrastructure, someone might still find a way to disrupt it. I believe any objecting person to our case might capitalize on that point and try to use it to derail our efforts.

    Since this is my first read after finally settling in, I will try to take time to study all the other postings before I comment further.

    By the way, the price of milk has dramatically increased due to the claims that the corn used to feed livestock is being diverted for fuel production. This is a small point for many of us; however, many others who are on a slim budget see how such claims can impact their home lives. Thus, even a small point may create a creditable appeal for a group of people that can become an army of political supporters and concerned voters. For clarification, I do not mean to create a scare tactic.

  27. Coyote said

    Joe Russo! We are forever glad to have you back on line and to take your counsel good Sir!

    Keep making us think. Keep pushing us!

    Hope you are settled in and enjoying the new digs!



  28. Christine said

    when United Nations forces responded to the beleaguered Darfur region the value of simply broadcasting power immeidately to the relief efforts would have been priceless

    Until the Janjaweed blows up your rectenna or simply strips the wiring to be resold for scrap.

  29. Joe Russo said

    I reveiwd my past notes and found some thoughts I like to share:

    If an assertion is made that we can reduce the insurance claims and deaths overseas (specifically in Iraq), will that negatively affect our position through the related political associations with Iraq? I can see someone making a counterclaim that the problem of insurance claims and deaths will disappear after an existing plan to the ware, so we do not need to spend money on solar power technology. I think the assertion of insurance claims and deaths is good to make it a general statement not specific to Iraq; or a suggestion to Iraq. I think it is better to argue that we need to start implementing a fuel alternative along with all the other alternatives.

  30. Joe Russo said

    Dan, about radiation protection,

    The idea that we could use lunar material for radiation protection is interesting. Could someone send more details on that?

    There area other methods too other than lunar materail.

    If radiation protection is an issue, please refer to this article by NASA about Plastic Spaceships

    “…Most household trash bags are made of a polymer called polyethylene. Variants of that molecule turn out to be excellent at shielding the most dangerous forms of space radiation…”

  31. Joe Russo said

    I was hoping for more details. Thus it is speculation. I hope that one day it does become proven 🙂

  32. Edawg said

    The fear of nuclear technology has cost us the NERVA program…and will pray not be factored in SSP consrtuction thus leading to its failure.

  33. Joe Russo said


    Thank you for pointing that out.

    Unfortunately I personally also know how damaging fear pushes people in the wrong direction: titled Research Paper of American Values under Attack by Bigotry

    Since 9/11 it has been a nightmare for my family and I, however, we use our experiences to help others now.

    As for our efforts, I can see the potential occur were we are talking to elected officials about our solar power claims, and a lady from the public stands up, with a group of people, shouting, “They are killing our babies!” How do we handle that? I believe the best way to handle the fear-based reaction of a misguided person is to use education and preparation.

    Education outreach is important. I believe se must be prepared to handle rebuttals, questions, and concerns. I think we also need to continue our outreach education efforts. After all, using education and scientific study finally ended the long lasting fear of using hydrogen fuel as a fuel alternative. How many decades did people fear the use of this alternative because of the Hindenburg accident?

    The politics is important. The fear-based reaction that solar power
    technology might be used as a weapon is an old fear that might have been developed during the construction of Reagan’s Star Wars.

    Finally, the technical side is important. Long ago, the utilities companies were under attack by an angry public that believed that the magnetic energy coming from the power lines was killing people. The crux behind this issue was actually a real estate issue, and the public was pushed to believe that the utility companies were bad. In the end, it resulted in an unhealthy and unrealistic fear. One of my friends who was working outside on a survey crew for a utility company said that a woman came out of her house, crying and screaming to the survey crew, “How can you sleep at night? You’re killing our babies.” Fortunately, the public finally became aware of the technical facts and the opposing mobs started to dissipate.

    Will some of the public become concerned? Yes, and it is up to us to help to keep them from becoming unrealistically fearful.

    I do understand that some people are upset about the past that have been made in reference to oil, but that was the option that was found to be best at the time. Let us be supportive, and create better options now.

    This starts by planting positive seeds in terms of what we can do for the future, and then we must water those seeds instead of watering old ones. Also, in my personal opinion, being confrontational is not watering positive seeds for the future.

    If anyone needs me, please email me for I will be off line for a little while.

  34. Joe Russo said

    By the way, today the cost of gasoline in Orlando Florida was over $4 per gallon. I will try to get more news on that.

  35. Edawg said

    The way I see it society as a whole is erroding because we are not expanding, Western civilization can only exist in a constant state of expansion or else it stagnates.This has been true since the Romans. Our nation is on a very slippery slope. The whole reason why space advocates haven’t gotten anything done in 40 years is because they are still stuck in defensive formation. This is America; all thats needs to be done is the proper dissemination of information and everything will take its proper course…like this forum. I personally think that we do not have till 2050 to get this thing up and running.[…]

  36. Joe Dura said

    I have four brief comments as I try to assimilate all that is written on SSP

    1 – If the military need is for 5MW on the ground, why do you need 5MW satellites? Perhaps the economies of scale would be better to have, for example, 5 satellites at 1MW each all beaming to the ground-based receiver.

    2 – There is no need for orbital tugs etc. Just assemble the SSP satellite in LEO and include a tank of Xenon and an ion drive. Eventually it will get to GEO and have some maneuverability once there. The solar panels can supply much more energy than the drive would need.

    3 – Another use of an SSP is to power ion drives for cislunar or planetary spacecraft rather than using heavy on-board sources of power like reactors or large solar arrays. I doubt that this is an original idea, which brings up a point, is there a webpage that compiles, in one place, lists of the pros, cons, uses, etc. of SSP?

    4 -I’ve found that discussions of proposed technologies often benefit from a strawman plan (or several). People can see in actual numbers what is required, and where improvements can be made. Does such a plan exist? If not I would recommend that we start defining the requirements for a Reference SSP Demonstrator Mission based on COTS technology, LEO assembly from 1-3 launches, ion propulsion to GEO, etc. Once the outline of what is included in the RSDM is established, someone can specify actual hardware to flesh out the RSDM and run the numbers. Once the RSDM is written we will have a starting point to determine power capacity, upfront costs, operational costs, ground system requirements, etc. The system can then be improved upon by analyzing real world alternatives. If an alternative is found beneficial it can either replace the baseline RSDM, or create an alternative RSDM. This system can then evolve, and provide input to the decision makers at DOD, DOE, FEMA, NASA etc. on follow on studies etc.

  37. Edawg said

    2 – There is no need for orbital tugs etc. Just assemble the SSP satellite in LEO and include a tank of Xenon and an ion drive. Eventually it will get to GEO and have some maneuverability once there. The solar panels can supply much more energy than the drive would need.

    […] Orbital tugs can be used for more than just ssp construction. […]

  38. Dan Lantz said

    Joe #34-4:
    present “end point” plan for global power/climate-change solution. What is needed is path/strawman plan to get to the larger LSP plan from small “current” starting needs. I propose “worst case assumptions for LSP” plan: (1) All manufactured parts Earth launched, to Moon rather than geosync orbit. (2) Moon “only” supplies station keeping (for life of project), any needed radiation shielding (bury sensitive parts), basic structure (Moon’s surface is already there), large antennae size/platform (optically larger than SPS by far), and “junk” remediation/prevention (blasted pieces mostly stay on Moon). Also, astronomers won’t complain as much. IF this plan is anywhere near as good as SPS, start thinking about using more and more manufactured lunar resources instead of Earth launch. It soon becomes a “slippery slope” up to Space!

  39. Joe Russo said


    I do not agree or disagree with you. It sounds great in the long run; however, I do not see any lunar resources on the market today. I believe that is one reason why the Bush Administration is pushing for back to the Moon. The Clinton administration did not go for the Moon which also killed the efforts of many to build a manufacturing plant on the Moon. But that is history and we need to move on. Yes, it might be best to build Moon bases first, however, can we wait that long? Can you show us detail on how long it will take and the outcome? I am seeking this information too. Again, I suggest we build with what we have today? I understand you claim that will take money from Moon infrastructures again, and just delay what some people think we need instead, however, there is still too many uncertainties about a lunar resource that is not on the market??????? What is your opinion of making one SPS with what we have today; at the same time develop a lunar base to try to make other SPS with ISRU instead?


  40. Joe Russo said


    Who wants to join me in developing a feasibility study on using lunar resources to develop SPS?

    I had started on in the 80’s. It was put on the back burner when I was hired as an engineering consultant for several companies in energy production to distribution to developing devices in support.

    My commercial email address is

  41. Dan Lantz said

    Joe #37:

    Let me outline my specific goal for this particular SpaceBasedSolarPower study, then answer your questions more explicitly. Your questions go the the heart of the matter.
    My basic goal is that this SBSP study look at two distinct but connected questions:
    (1)I want this SBSP study to look far enuf into the future that it estimates a power collection scale which will, in any way possible, come anywhere close to justifying the start of InSituResourceUtilization development. This may vary with differing overall plans. Think of sharing expense/product with other projects, some already in the works. Fully realize that ISRU is a big, important step to get started on ASAP!
    (2)Look at SolarPowerSatellite vs. Dr. Criswell’s LunarSolarPower, but starting with NO lunar manufacturing, only very primitve lunar ISRU, as outlined in #36 above. All manufactured parts Earth launched, but fewer needed for LSP plan than SPS. NO ADDED DELAY to do this over Earth launched SPS. If it is anywhere close to SPS, favor it and start thinking in terms of more ISRU. Obviously starting with NO DELAY LSP plan will help eventual ISRU “yes!” to question #1.
    If study shows both (1) and (2) to be way out of range, at least there is scale estimate to present to global climate change/global energy market planners, and maybe they will start SBSP. The problem is going from very small to very big(where we know ISRU is only option).
    To answer your excellent questions:
    “build with what we have today”
    As mentioned elsewhere, I like the idea of starting with redirect (small, non-collecting) satellites, start with redirecting Earth surface power, then can re-use redirects when SBSP starts. Quick and dirty solution for small, isolated users without wasting any resources or time. Like this better than Earth launched SPS and Moon ISRU at same time, as that seems to waste some effort.
    Incidentally, redirects may eventually only be needed for polar areas, as most customers will probably have fuel cells to make vehicle fuel of some sort, and these fuel cells can provide electricity to combine with stored hot/cold water to get thru the very predictable ~16 hrs/day when Moon is not high. One Moon thus serves all non-polar destinations, instead of needing several SPSs or redirects. It is a matter of expense comparison.
    I’m not against Earth launched small SPS (it would prove Space solar power concept, get people used to the idea, and tie down the frequencies, something maybe only the military can do) or Apollo-style (don’t stay/don’t develop) Mars shot(s).
    What I am against is the ASSUMPTION that doing these sorts of things with ISRU/LSP need not be considered because that would be far more expensive than (forseeably cheap) Earth launched versions.
    My main concern is that ISRU/LPS is realistically included in the study, then I am satisfied!
    “Long run” is my focus. It is obvious that on a grand scale the Earth does not have the resource to support Space colonization(bioization), even if launch cost is zero.
    On smaller scale, we need to consider when the savings from ISRU/LSP overcome initial cost (as an investment), and it becomes more efficient than Earth launched plans. ISRU pays back geometrically over time, especially as different projects use factory product. Getting started ASAP is the key. Criswell’s full Lunar Solar Power project is TOO BIG for Earth launch. Those who really need the electricity will be the first to support it: those who need lighting and refrigeration and who can build rectennae to receive energy from Space.

  42. Jennifer Bond said

    For many years I was the epitomy of hope and optimism. During the waning days of the 20th century, the bloodiest century in human history, I was excited about the prospect of a new century. Sadly, what I have seen is a civilization still driven by reaction instead of proaction. This project would go far in the maturation of our species, I pray and hope our world leaders seriously consider this project for global security sake.

  43. Neil Cox said

    Too many generalities and letter groups, unfamiliar to people with different specialities. Please try to make your meaning clear. Someone inferred that a few holes blown in a rectenna would still allow 2/3 power output. Only if the rectenna is designed with that in mind. Assume a round or slightly oval rectenna with a diode for each small group of dipoles. A typical diode might produce 2 volts of dc across a capacitor. The capacitors are wired in series and 30 of these small groups of dipoles are arranged along a radius of the rectenna. Each adjacent pair of radii are wired in series near the center of the rectenna. 1200 volts dc is thus avalable near the outer edge of each radius pair. This runs an inverter which produces 500 volts, 60 hertz ac We now need several redundant paths to tie 100 inverter outputs in series to provide one of the three phases of a 50,000 volt electric power transmission line. Somewhat fewer inverters will be connected in series if less than 50,000 volts is optimum for the local grid connection. Lots of redundant wiring is needed, so we don’t lose the whole phase because of the distruction of a few pieces of wire. Depending on how many megawatts are in the beam, we will have three or perhaps 30 of these phases. Failure of some of these phases will unbalance the local grid a bit, but this only reduces efficiency slightly.
    We will not be able to put more than three phase junctions close to the center, so additional phases will need to be closer to the perimeter of the rectenna and shaped differently. Please suggest other geometries which can tolerate a few holes blasted in the rectenna. Neil

  44. […] Proponents of the technology are looking at this scenario: [B]y 2050 the goal is to have forty or so concentrator-photovoltaic space-based solar power (SBSP) satellites in geostationary orbit, each broadcasting via microwave between 2-5 gigawatts of power to terrestrial electrical power grids, with 1-to-5 broadcast antennas that can beam power to as many locations. […]

  45. Neil Cox said

    If we expect to propel vehicles in a war zone, with laser beams by 2012, we need to work several SBSP (space based solar power) projects simultanously. Such a laser beam will be deadly to humans, unless the vehicle can carry a 10 square meter energy receiving array. High flying balloons can likely be first, at least cost, followed shortly by LEO = low Earth Orbit, followed shortly by GEO orbit = geosynchronous orbit, which is least vulnerable of our near term options. The vehicle will occasionally outrun the beam from GEO altitude, when sudden turns are made, due to the 0.4 second response delay over a range of 36,000 kilometers. Any SBSP beams not needed for a vehicle can power fixed energy receivers. Vehicles can supply about 100 kilowatts where ever they are parked.
    A puny SBSP might be towed to the moon and some test bed factories, by 2020, but I don’t see useful SBSP Moon to Earth, before 2050, even if we throw ten billion dollars per year at related projects begining in 2008.
    I suspect klystrons cannot efficiently beam power from moon to earth, with a rectenna smaller than a million square kilometers, because of beam spreading, so we should concentrate on laser diodes, if we are reasonablely sure we can build a billion of them by 2012, at 50% efficency or better. I posted some more details in some of the other threads. Neil

  46. Marshall D. Martin said

    I am a friend of The Space Show. I ask a lot of questions. Here are a few for you guys.

    A) What is the optimal launch system for this project? 1000 lb. to LEO is too small and 200 tons to LEO maybe too expensive. A wrong calculation could doom the project to a 10 year delay.

    B) Who and how are the space robots going to be maintained? ISS is in the wrong orbit & tours of duty are too short.

    C) Is a real space station (O’Neil quality) required to build a 5MW SSP? Maybe a real space station has to be put off until the first 50MW SSP.

    D) Are we going to use much cheaper lunar materials or launch 100% of materials from Earth (expensive).

    I have a lot more questions that must be answered before you guys can be taken seriously,
    Marshall D. Martin

  47. Coyote said

    Marshall D. Martin: All good questions that will be part of subsequent studies. This was a Phase Zero architecture study that surveyed the scope of the problem. Most of your questions won’t be answered for a number of years or decades. We will need empirical data from tests and demos to satisfy our curiosity before we design the final systems. Yes, it will be cheaper doing many things from the Moon, but it will be horrendously expensive to set up the infrastructure on the Moon to duplicate our fabrication capabilities that we have on Earth. Plus, we have Earthlings who want jobs here and politicians that like keeping their constituents employed. I wonder how it will turn out? Keep asking questions, and never take us too seriously 🙂


  48. Dan Lantz said

    Marshall #46:

    (C)You had me scared there: I thought I had misspelled “O’Neill”! Also, think at least 100 GWe or you are not relevant to global concerns.
    (A) Cheapest is optimal. Once in Earth orbit, it gets much easier.
    (B) Directly controlled telebots fix broken space robots. Mars rovers give popular icon for combination of man and robot Space cooperation.
    (D) It depends upon how smart we are (I Kid!).
    Taking me seriously may lead to thinking effort. Do so at your own risk.

  49. Dan Lantz said

    #47 Coyote:

    “it will be horrendously expensive to set up the infrastructure on the Moon to duplicate our fabrication capabilities that we have on Earth”
    What we need is fabricated fabricators launched to the Moon, as first order task, so that “break even” is reached ASAP. When lunar factories are producing ~their own mass as product, break even has been reached. Criswell sez they should make 100-1000 times their mass as reasonable expectation. Small advantages grow to large differences over time in these matters. Don’t wish you had, be glad you did!

  50. Neil Cox said

    This wikipedia article which follows is likely the tube which will produce the microwaves or millimeter waves. The TWT = traveling wave tube can operate up to 50 gigahertz = 6 millimeter waves:
    Wikipedia, the free encyclopedia

    A crossed-field amplifier (CFA) is a specialized vacuum tube, first introduced in the mid-1950s and frequently used as a microwave amplifier in very-high-power transmitters. A CFA has lower gain and bandwidth than other microwave amplifier tubes (such as klystrons or traveling wave tubes); but it is more efficient and capable of much higher output power. Peak output powers of many megawatts and average power levels of tens of kilowatts can be achieved, with efficiency ratings in excess of 70 percent.

    The electric and magnetic fields in a CFA are perpendicular to each other (“crossed fields”). This is the same type of field interaction used in a magnetron; as a result, the two devices share many characteristics (such as high peak power and efficiency) and they have similar physical appearances. However, a magnetron is an oscillator and a CFA is an amplifier; a CFA’s RF circuit (or slow-wave structure) is similar to that in a coupled-cavity TWT.

    Raytheon engineer William C. Brown’s work to adapt magnetron principles to create a new broadband amplifier is generally recognized as the first CFA, which he called an Amplitron. Other names that are sometimes used by CFA manufacturers include Platinotron or Stabilotron.

    [edit] External links
    CFA tutorial on the CPI website

  51. Neil Cox said

    Hi Marshal: I agree it will take a decade or more to work out the details for a 5 or 10 gigawatt SBSP, but I’m hoping for a demonstration SBSP in low Earth orbit by 2015. An orbit simular to the ISS will be ideal as the SBSP can beam power to most of the cities of Earth about 1/2 hour per day, which will be an excellent demonstration.
    We should be thinking about 20 tons for the demonstration SBSP.
    I don’t think an O’Neill colony will be much help building any kind of SBSP. All the materials will come from Earth for a 2015 or 2020 demo, but by 2040 the Moon and/or asteroids may be making significant contributions to scaled up SBSPs. IMHO = In my humble opinion, we need dozens of small steps to get to 100 gigawatts. Big steps often cause big, expensive errors. Neil

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