Space Power is about the generation of power from space.

The space around Earth is filled with intense sunlight, undiffused by atmosphere, continuously. It represents an inexhausible supply of energy that can be converted to electricity using semiconductors - that is without the use of any moving parts.

A small fraction of this energy could supply a large part of the world's future energy requirements for the foreseeable future. In addition, it could do it without the need for any kind of fuel, and without producing any waste product.

All that's needed is large-area collectors - and that means large, thousands of square kilometers - and a way to transmit the collected power down to Earth. Several different methods are possible, but the one that has received the most effort so far is the use of microwave beams or wireless power transmission.
29 July 2012
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16 July 2012
Space Future has been on something of a hiatus of late. With the concept of Space Tourism steadily increasing in acceptance, and the advances of commercial space, much of our purpose could be said to be achieved. But this industry is still nascent, and there's much to do. this space.
9 December 2010
Updated "What the Growth of a Space Tourism Industry Could Contribute to Employment, Economic Growth, Environmental Protection, Education, Culture and World Peace" to the 2009 revision.
7 December 2008
"What the Growth of a Space Tourism Industry Could Contribute to Employment, Economic Growth, Environmental Protection, Education, Culture and World Peace" is now the top entry on Space Future's Key Documents list.
30 November 2008
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Equatorial Times No.6
The Newsletter of the SPS 2000 Community Around the World

Editor: Dr Patrick Collins

Isolated communities high in the Colombian Andes near the Equator
Welcome to this Issue

In this 6th issue of "Equatorial Times" we report on our 1998 visits to Malaysia and Colombia where we visited government representatives in the capitals of Kuala Lumpur and Santa Fe de Bogota, the campuses of the National Universities, and potential rectennas sites.

We report on a paper on SPS 2000 rectenna siting research in Indonesia presented at the Thailand-Japan Joint Symposium on Antennas and Propagation in Bangkok.

We also report on SPS-related web-sites on the Internet - plus SPS News from around the world, and another style of "mini-rectenna" from Indonesia. SPS 2000 rectenna siting research in Indonesia.

Dr Yuliman Purwanto of the Department of Electronics, Faculty of Engineering, Satya Wacana Christian University (SWCU) in Salatiga, Central Java, presented a paper entitled "A Preliminary Study of Rectenna Development Aspects in Indonesia for SPS 2000 Energy Reception" at the Thailand-Japan Joint Symposium on Antennas and Propagation (JSAP) held from May 2 1-22, 1997 in Bangkok. The paper was co-authored by F Dalu Setiadji, also of Satya Wacana University, and Patrick Collins, then at RCAST, University of Tokyo. This presentation was the first time that a paper on the SPS 2000 project has been presented at a conference outside the main industrialised countries (although SPS featured at the International Symposium on Antennas and Propagation (ISAP) in Chiba, Japan in 1996).

The 1st section of the paper introduces the subject of SPS and the SPS 2000 pilot plant project proposal.

The 2nd section "Rectenna Location Considerations" discusses the siting requirements for SPS 2000 rectennas; selects the Moluccas in eastern Indonesia as an attractive candidate location in Indonesia; and lists 5 types of location: a) in an inland forest, b) in an inland area, c) on the coast of a large island, d) offshore from a large island, and e) on an unpopulated small island (coral island). The relative advantages and disadvantages of each of these possibilities are then discussed. It is concluded that of the five different possibilities considered, all except siting within a forest seem likely to be acceptable.

The 3rd section, "Cost Problem", discusses the funding of an SPS 2000 rectenna, explaining that it would not be cost-effective for a developing country to pay for one as an energy source. Note: this argument is correct! SPS 2000 is a pilot plan 1 and is not expected, or intended, to be commercially competitive. That is, the cost of the rectenna will be very high relative to the amount of electric power that it will produce. For this reason it is anticipated that if the project is realised the Japanese government will pay for the rectennas as well as for the satellite and its launch.

Photograph of a 2.45 GHz oscillator developed by students at Satya Wacana Christian University, Salatiga, Central Java.

The 4th section of the paper, "Research Involvement Required" discusses the possible roles that researchers in Indonesia could expect to play in the SPS 2000 project, with a view towards participating in later commercial SPS projects. The main possibilities include 1) preparing rectenna case studies, 2) evaluating possible forms of involvement in SPS and SPS 2000 by Indonesia, 3) studying research needs for future SPS utilization in Indonesia, 4) forming links with researchers in other equatorial countries, and 5) applying for preliminary research funding from various bodies, both national and international.

The final section of the paper concludes that SPS has considerable potential as a source of electric power for the future, and that a study of SPS system utilization would be of value to Indonesia in the near future.

As an equatorial country comprising many thousands of islands and extending thousands of kilometres from west to east, Indonesia has important geographical advantages for receiving microwave power from space, including also for re-export to its many neighbours. An island in North Moluccas is strongly recommended as a suitable site for the first equatorial rectenna in Indonesia.

Currently the main obstacle constraining research on SPS 2000 at Satya Wacana University is lack of research funding and lack of necessary equipment for microwave measurements. It is hoped that grants and/or loans of equipment will become available to help overcome these problems in the near future.

Field Research Around the Equator (7 & 8)

Using grants awarded by the Japanese Ministry of Education, Science and Culture ("Monbushoh" in Japanese), field research to study the feasibility of siting SPS 2000 rectennas in equatorial countries has been under way since 1994. The objectives of this research are to make contact with colleagues in candidate countries; to have initial discussions with government representatives and other interested parties in those countries; to identify candidate rectenna sites; to develop preliminary ideas about appropriate rectenna designs for each site; and to consider how each rectenna might best be utilised.

In January 1998, Professor Hideo Matsuoka and Dr. Patrick Collins visited Malaysia, the 7th visit in this series, and in September they visited Colombia, the 8th. As in earlier field visits to Tanzania, Papua New Guinea, Brazil, Indonesia, Ecuador and Maldives, there was considerable interest among officials and researchers in both Malaysia and Colombia in participating in the SPS 2000 project by hosting and operating a rectenna, and by participating in related research.


Professor Matsuoka and Dr. Collins initially visited the Ministry of Energy, Telecommunications and Posts in the capital, Kuala Lumpur, where the Secretary General of the Ministry held a briefing meeting attended by some 20 officials invited from other ministries, universities and states.

Although Malaysia has no shortage of energy, the government is interested in developing high technology industries, and participation in SPS 2000 was felt likely to be valuable in this respect, by leading towards the development of a commercial space industry.

Malaysia has large areas of relatively undeveloped land near the equator in Sarawak province on the island of Borneo where many people still live without electricity. Unfortunately there was not time to visit Sarawak on this occasion; however, participants in the meeting included representatives from Sarawak.

Another idea that was discussed was the possibility of holding an international conference on power from space in Kuala Lumpur, in 1999 or 2000. This will depend on obtaining a budget to cover the expenses.

A visit was then made to the Universiti Teknologi Malaysia (UTM) in Kuala Lumpur, and the Department of Electrical Engineering at UTM's main Skudai campus near the southern town of Johor Baru, on the border with Singapore at 2 degrees north latitude. There was considerable interest in collaborating on planning a Malaysian SPS 2000 rectenna, and the possibility of siting a "research rectenna" within the UTM campus was proposed. Since there are engineering and other researchers at the campus, it could be a good site for a rectenna designed specifically for performing a range of experiments on SPS operation. The value of a dedicated research rectenna has been discussed for several years, but a suitable site had not yet been identified; UTM seems a good host.

Main buildings of the Skudai Campus of Universiti Teknologi Malaysia (UTM) near Johor Barn

Professor Matsuoka and Dr. Collins initially visited the Institute for the Promotion of Science and Technology, Colciencias in Santa Fe de Bogota, the capital. Like Malaysia, Colombia has plentiful energy resources, and no fears of shortages for the forseeable future. However, it was felt that participation in a leading-edge technology research project such as SPS 2000 is a rare opportunity which could be valuable both technically and politically.

Professor Matsuoka and Dr. Collins also visited the Department of Electrical Engineering at the Colombian Engineering School, and the National University, where the Deans and staff expressed support for Colombia's participation in the SPS 2000 project. They also gave presentations to staff and students about the SPS 2000 project.

Professors Sanchez, Ruiz and Matsuoka at a site in Narinho University Agricultural Research Centre

Later they visited potential rectenna sites in the countryside near the town of Pasto in the southern state of Narinho. Sites seem feasible both near the village of Tuquerres, and at the agricultural research station of Narinho University near El Espino.

Issues arising

There is no near-term energy problem in either Malaysia or Colombia, as both countries have plentiful resources of oil, gas and coal, as well as potentially large solar energy capacity. Colombia also has large hydroelectric resources.

Like other countries in south-east Asia, Malaysia has achieved rapid economic growth partly through developing industries based on new technologies. Solar energy is seen as having great potential as an energy source in the future, which could become an important new field of technology, like aerospace. Thus the Malaysian government was interested in hosting a rectenna, and UTM proposed to host a rectenna within the grounds of its main campus.

Among south American countries, Colombia has recently had the most stable economic growth and it has the longest history of democracy; thus it has correspondingly long experience of diplomatic activities. There was discussion during the visit of possible diplomatic initiatives relating to SPS and SPS 2000, perhaps starting among equatorial countries, in order to encourage the realisation of the SPS 2000 pilot plant system.

Copies of the full reports on the Malaysia and Colombia field research visits are available on request. The next visit will be to the pacific islands of Kiribati and Nauru during February 1999.

Language corner

Talking with colleagues in Colombia we learned that "achichi!" is an exclamation used in some regions of the country when a person touches something painfully hot.

In Japanese the word "atsui" means hot, and when you touch something hot you say "atsui-atsui!" - which in practice sounds surprisingly similar to "achichi".

There are stories of Japanese people having gone to live in Colombia and other south American countries some hundreds of years ago. And it is said that some south American children are borne with the "Mongol spot", a darkening of the skin at the base of the spine which most Japanese, Korean and Chinese children have for the first year or two of their lives.

So although Japan is not an equatorial country, as a 'Pacific Rim' country its language could have reached south America. - Or is "achichi!" just a noise expressing pain - like an intake of breath?

More expert linguists than us are required!

SPS World Wide Web Sites

There are many Internet web-sites relating to space activities such as astronomy, space science, rocket launches, the history of astronautics, NASA and so on. Sites concerning power from space are only a small sub-group - but they are a most important one, since this is one of very few ideas for space activities that may become profitable and thereby contribute to world economic growth. is the site of the Sunsat Energy Council, which was set up 20 years ago, and recently merged with the Space Transportation Association (STA) in Arlington, Virginia. It contains copies of SPS papers by Peter Glaser, the inventor of the SPS (in 1968), John Mankins, now responsible for SPS studies at NASA, and others. It also gives links to several related sites. For example, HOMEPAGE.HTML is a site at Texas A&M University dedicated to the work of Bill Brown, the "father" of WPT (wireless power transmission). Also is the site of the Space Studies Institute which was founded by Professor Gerard O'Neill and concentrates on research on the use of extra-terrestrial materials (such as aluminium from the Moon) for constructing SPSs. This approach is expected eventually to reduce the market price of materials in Earth orbit below the cost of launching them from Earth. is a lecture entitled "Solar Energy Resources - Orbiting Solar Power Satellites" by Professor G Kulcinski at the University of Wisconsin. This is an example of a trend among university teachers - making their teaching materials available to everyone through putting them on a web-site. This enables everyone to benefit from the fact that knowledge is cumulative, and avoid the wasted effort of repeating the same work. is another site dedicated to using extra-terrestrial materials for space activities, and has a sub-section about SPS, with a good list of further Internet links. is a section of the "Space Future" site dedicated to SPS and particularly to the SPS 2000 pilot plant project. Among other material, it contains back issues of Equatorial Times, as well as papers on SPS and SPS 2000 in the library section. is a section of the famous "NASA WATCH" site (which is a continual critic of NASA's more wasteful activities) dedicated to SPS. Like everyone else who has an hour or two to browse the World Wide Web, you'll probably find that one interesting-looking site leads you on to another - and another and another! Please let us know of any interesting SPS-related sites that you find! You may also find that some sites no longer exist - or are no longer at the site where they were. This is a feature of the Internet - it's a volatile medium within which major changes can occur at the press of a key!

More sites in future.

SPS News
Plenary Session on SPS at IAF in October

For the first time, SPS was the theme of a special Plenary Session of the International Astronautical Federation (IAF) annual congress held in Melbourne, Australia from September 28 - October 2. Organised by Brian Erb of the Canadian Space Agency and Professor Nobuyuki Kaya of Kobe University and currently Chairman of the LAF Power Committee, this was a good opportunity to bring SPS to the attention of space experts from other areas of specialisation.

Many papers on SPS were also presented at the three SPS-related sessions at the Congress, showing that despite the continuing lack of serious funding for SPS research (compared to the many $billions spent every year on other energy and space projects) researchers are still convinced that it's a good idea.

17th ISAS Space Energy Symposium

The 17th ISAS Space Energy Symposium was held on February 17th, in a somewhat different format from the past, being jointly held by ISAS and the newly-established Space Solar Power Research Society. Of the 2-day meeting, one session comprised a Forum at which 5 speakers gave presentations on different aspects of SPS - power transmission, power generation, transportation, space manufacturing and economics - intended to help focus different disciplinary approaches on a near-term research program. Next year, in addition to the 18th ISAS Space Energy Symposium on February 16th, a separate symposium on energy from space will also be held on January 8th at the University of Tokyo.

New Grant received for SPS 2000 Field Research

An additional grant has been awarded to Professor Hideo Matsuoka, Professor Makoto Nagatomo and Dr. Patrick Collins by the Ministry of Education, Science and Culture in Japan to enable them to continue their field research in equatorial countries to initiate collaboration on the planning of SPS 2000 rectennas at suitable sites near the equator.

The first visit using this new grant was made to Colombia in September; the next will be to Kiribati and Nauru in February; the third visit will be to Gabon in West Africa; and the fourth has yet to be fmalised. This grant will support this field research until the spring of the year 2000. By that time it is hoped to have a "full house", with all candidate countries agreeing to participate. The current estimate is that sites will be agreed for 15 rectennas in 11 different countries, which will enable the SPS 2000 satellite to achieve a 50% utilisation rate. (Achieving more than that would require building rectennas in the open sea!) 50% utilisation should be enough to attract other organisations to build additional satellites to supply more power to the same rectennas. We are also looking to obtain cooperation of non-rectenna countries near the equator on such research as transmission experiments concerning the microwave beam sidelobes, and upper-atmosphere impacts of the microwave power beam.

US Congress triples NASA's SPS research budget

The Space Subcommittee of the US Congress voted in late 1998 to increase NASA's 1999 budget for SPS research from $5 million to $15 million - although NASA did not request this. Members of the Subcommittee want NASA to make greater efforts towards commercialization - and energy supply is a major candidate. However, NASA's leaders prefer to plan a taxpayer-funded mission to Mars. In view of NASA's reluctance to work on SPS, it will be interesting to see how it uses the money. The Subcommittee is likely to keep pressure on NASA to use its funding to benefit US taxpayers economically.

Mini-Rectenna Corner
Mini-rectenna made by students at SWCU

In this issue we present a mini-rectenna made at Satya Wacana Christian University (SWCU) in Salatiga, Central Java, Indonesia. As can be seen, the antenna is a crossed-dipole type with a wire-grid reflector mounted on a wood substrate. The dipole size is 1/2 wavelength (ie approximately 6.2 cm), and the wire-grid dimension is 1/6 wavelength. Although the design is very simple, it is reported to work well, and has been used to detect microwave energy leaking through the door of a microwave oven.

Mini-rectennas are a good way of demonstrating WPT and explaining the concept of SPS. They're also very cheap to make, requiring some wire, a couple of diodes, some wire mesh and, in this case, a piece of wood. We are happy to help SPS 2000 researchers make their own mini-rectennas, by providing information and/or components. We particularly like receiving photographs (or better, samples!) of mini-rectennas made by readers in different countries.

Regular Safety Note: Some people, when they see a mini-rectenna being demonstrated, say: "Look - microwave ovens are dangerous, because microwaves leak out of them!" However, this conclusion is incorrect. Microwaves do leak from ovens, but their intensity is set by an international safety standard. For the general public, the intensity of continuous-wave radiation at 2.45 GHz must be less than 10 W/sqm (= 1 mW/sqcm). Mini-rectennas can pick up microwave power at even lower intensity, and convert it to DC electricity. So all ovens leak a certain amount within the safety limit, which is not dangerous.

Editorial - Energy Options Shrink with End of "Fast Breeder" Nuclear Research

In February 1998 the French government finally decided to close down their research on "fast breeder" nuclear reactors (FBRs) which has been plagued with accidents and cost overruns. The "Super Phenix" reactor had cost some $10 billion and was finally closed down after a major accident caused several $billion of damage.

In taking this decision, France followed the path already taken years earlier by the USA, Germany, Russia and Britain. All of these countries had also spent $billions trying to develop the FBR system, but all had concluded that it is not a promising approach to electricity generation.

The system has a fundamental design problem - it contains a liquid sodium/water heat-exchanger. Readers may remember their school chemistry teacher doing a simple experiment placing a small piece of sodium metal the size of a match-head on the surface of a beaker of cold water. In a highly "exothermic" chemical reaction (in which 2Na + 2H20 => 2NaOH + H2) the sodium skitters about on the water surface hissing fiercely.

So you can imagine the reaction when even a pinhole leak arises in the heat-exchanger: the pipes melt and tons of molten sodium mix with super-heated water - truly spectacular! In a blaze that cannot be dowsed with water (!) it fills the reactor with burning hydrogen gas and solidified sodium hydroxide. Not to mention leaving the remaining pipework filled with solid sodium metal.

This was the multi-$billion accident that finished the "Super Phenix" reactor in France. A similar accident also occurred at the "Monju" reactor in Japan a few years ago. Announced at first as a small accident, an official video was later shown to have been deliberately falsified to minimise the apparent damage - which has put the reactor out of operation ever since.

It's generally agreed to be only a matter of time before Japan's FBR work is also finally stopped. However, it's a weakness of Japan's "consensus" system of decision-making that it is very slow to correct mistaken decisions (as seen also in Japan's extreme delay in correcting its economic policy since the economic bubble of the late 1980s). The truth is that in every country, research on "fast breeder" nuclear reactors was a result more of the distortions in government science and technology policy caused by the Cold War than of rational energy policies.

The central role of nuclear weapons in maintaining the balance of power during the Cold War era gave the nuclear industry enormous influence in society. For example, note how many universities have nuclear engineering departments. One result was that, in addition to large portions of official defence budgets, nuclear engineers also devised many other means of subsidising related research. Research on "fast breeder" nuclear reactors paid for a lot of research on plutonium, a key ingredient of nuclear weapons.

Judged by any objective standard, to have spent tens of $ billions on a power generation system that is not only now admitted to be impractical - both unsafe and uneconomical - but which was widely criticised for being so from the very start - is an amazingly costly error of policy-making.

And the extreme length of time it has taken to admit the truth and close the research down is further testimony to the power of the status quo. Spending most energy funding on nuclear systems, and almost nothing on new possibilities such as SPS has been a costly mistake. Indeed, the restructuring currently under way in the global electricity industry is showing nuclear power to be another "smokestack" industry which may not even be able to survive fair commercial competition.

By contrast, even if the SPS 2000 project was judged to be a "failure", we would spend only a fraction of the amount wasted on "fast breeders". Indeed, if given the same amount of money, SPS people could develop the low-cost launch systems we need as well!

And there is of course a high probability that we will in fact develop what will become a major, new, clean and inexhaustible source of electric power for the entire world - clearly an extreme bargain compared to the FBR fiasco.

In 1998 the US Congress tripled NASA's SPS budget from $5 million to $15 million in frustration at NASA's lack of effort in this area. Hopefully this is a sign that we are finally moving towards a new attitude to SPS, and to a truly global energy source appropriate for the post-Cold War era.

As governments fight global deflation caused by over-capacity in older industries and a lack of new ones,they should be concerned to stop loss making activities and to aim to earn a positive return on public investments in space technology. If they do so, they will have to start funding SPS research.

Teikyo Heisei Unversity in Chiba Prefecture, east of Tokyo, workplace of Professor Hideo Matsuoka, the leader of the SPS 2000 Field Research, and current Chairperson of the Space Solar Power Research Society.

Glossary of terms used
Fast Breeder nuclear Reactor
International Astronautical Federation
Institute for Space & Astronautical Science
Sodium Hydroxide
Rectifying Antenna
Solar Power Satellite
Square centimetre
Square metre
Space Transportation Association, USA
Satya Wacana Christian University, Salatiga, Central Java, Indonesia
Universiti Teknologi Malaysia
Wireless Power Transmission

Next issue, June 1999:
  • Field research visit to Kiribati and Nauru
  • Report on SPS Symposium

For correspondence, contributions or further information, please contact Patrick Collins at: National Space Development Agency, 2-4-1 Hamamatsu-cho, Minatoku, Tokyo 105-8060, Japan.
Fax no: (81) 3 5401 8671

Please send comments, critiques and queries to
All material copyright Space Future Consulting except as noted.