The Space Reviewin association with SpaceNews

SSP illustration
Space-based solar power does face technological challenges, but they may not be as insurmountable as some critics argue. (credit: © Mafic Studios Inc.)

In defense of the knights

In his recent essay, “Knights in shining armor” (The Space Review, June 9, 2008) Dwayne Day asserts that space-based solar power (SSP or SBSP) is a long way from realization, and that the recent report by the US National Security Space Office (NSSO) is of little significance.

I am one of the space advocates in the UK who have been promoting SSP (e.g. “A growth-oriented UK space strategy”, Spaceflight, January 2007, p.20–23; Letters, Spaceflight, January 2008, p.30; “Next Steps for Space Infrastructure”, Spaceflight, July 2008, p.277–278). Since Day reads Spaceflight (which he describes in another essay as the “publication of record”), it is clear that, although we have never met, I am very probably one of the people he had in mind when describing the renewed interest in SSP among the space activist community.

Usually, Day’s articles are among the best-written and most informative space commentary on the market. But this time he appears to have made a number of unjustified assertions.

SSP is not merely expedient, rather it is strategic, in the sense that it has the potential to permanently raise the whole of human civilization to a higher level of prosperity, security and spatial range.

He writes: “Space activists, who are motivated by the desire to personally live and work in space, do not care about SSP per se […] they have latched on to SSP because it is expedient.” There may well exist people who answer to this description, but if so, they must be remarkably shortsighted. The facts are clear: fossil fuels have served civilization well in the first phase of its industrialization (approximately 1700–2000), but possess a number of problems, of which the current climate hysteria is only one; the others concern the long-term sustainability and growth of industrial energy consumption. Therefore we can predict an imminent shift of the baseload energy supply away from fossil fuels to, most likely, a mixture of artificial nuclear fission and fusion, and terrestrial and space-based solar power.

I should add that my personal chances of ever living and working in space are zero. My concern is that society should make the best strategic choices for its prosperity and growth. Given the fact that almost all the natural resources of the universe of potential economic value are extraterrestrial, I am therefore bound to argue the importance of systematic access to those resources.

SSP is not merely expedient, rather it is strategic, in the sense that it has the potential to permanently raise the whole of human civilization to a higher level of prosperity, security and spatial range. According to Day’s reading of the NSSO study, this is not for us, but only apparently for future generations, many decades in the future: “The NSSO study […] states that we are nowhere near developing practical SSP […] that the technology to implement space solar power does not currently exist… and is unlikely to exist for the next forty years.”

This came as news to me. Since SSP has been regularly used on a small scale to power satellites for forty years already (in marked contrast to the development effort that has gone into nuclear fusion), how could the NSSO have concluded that the technology “does not exist”? What actually does the NSSO report say? It reports:

“FINDING: The SBSP Study Group found that Space-Based Solar Power is a complex engineering challenge, but requires no fundamental scientific breakthroughs or new physics to become a reality.” (p.20)

“FINDING: The SBSP Study Group found that significant progress in the underlying technologies has been made since previous government examination of this topic, and the direction and pace of progress continues to be positive and in many cases accelerating.” (p.20)

This sounds promising. Does it mean we’ll be able to start work in forty years time?

“FINDING: The SBSP Study Group found that individual SBSP technologies are sufficiently mature to fly a basic proof-of-concept demonstration within 4–6 years and a substantial power demonstration as early as 2017–2020, though these are likely to cost between $5B–$10B in total. This is a serious challenge for a capable agency with a transformational agenda. A proposed spiral demonstration project can be found in Appendix B.” (p.22–23)

Turning to Appendix B, we find that its introductory paragraphs point out that significant technological progress has been achieved in the past decade, which would allow an accelerated pace of progress compared with that proposed by NASA in the late 1990s. But Day is not impressed, for his article reads: “from a technological standpoint, we are not much closer to space solar power today than we were when NASA conducted a big study of it in the 1970s.” He seems to have been reading a completely different report.

Cheap access to space no longer as achievable as it seemed in 1978? This is a clear reference to the Space Shuttle. But a government shuttle is no longer where cheap space access is at.

Appendix B is subheaded: “AN AGGRESSIVE AND ACHIEVABLE SBSP TECHNOLOGY DEMONSTRATOR ROADMAP: 10 Years — 10 Megawatts — $10 Billion”. It offers an updated program to build “an integrated large-scale demonstrator, to be flown in less than 10 years, at a cost of less than $10B, and delivering power to the Earth of approximately 10 megawatts.” Again, Day’s assertion that the technology is “unlikely to exist for the next forty years” is completely contradicted by the actual contents of the NSSO study report.

In fact, rather than wait some decades, the Executive Summary goes so far as to conclude: “Considering the development timescales that are involved, and the exponential growth of population and resource pressures within that same strategic period, it is imperative that this work for ‘drilling up’ vs. drilling down for energy security begins immediately.” (p.4)

Is there any specific technology that could have caused Day to be so dismissive of the concept? Indeed there is, for he writes: “the report makes clear that the key technology requirement is cheap access to space, which no longer seems as achievable as it did three decades ago (perhaps why SSP advocates tend to skip this part of the discussion and hope others solve it for them).”

Cheap access to space no longer as achievable as it seemed in 1978? This is a clear reference to the Space Shuttle. But a government shuttle is no longer where cheap space access is at. In 2004 we saw the first space access by a privately-developed reusable spaceplane, and its successor is due to begin test flights later this year in the run-up to commercial service. Sure, it’s only suborbital. But people are queueing up to ride on the thing.

Here’s the key fact: SpaceShipTwo represents a completely different economic paradigm from the Space Shuttle because, for the first time ever, manned spaceflight is about to become a profitable enterprise. All hopes that humanity will create a spacefaring civilization rest on this paradigm change.

In ten or twenty years time a successful suborbital industry will surely develop a reusable spaceplane for large-scale economic orbital access. The demand for orbital tourist flights exists, and the suborbital service will demonstrate that a spaceline can be run in the same way as an airline. Virgin Galactic may fail. It has plenty of competitors. One day, somebody will succeed. It’s only a matter of time.

One of the leading spaceplane companies in the UK is Reaction Engines, based in Culham in Oxfordshire. Here, there has been major progress in developing a revolutionary new combined jet-rocket engine, thanks to £5 million (US$10 million) of private investment. Alan Bond, its founder and managing director, recently told me that the British government is now more supportive of their work than it has been for decades.

The Skylon orbital spaceplane that the company is promoting is a direct successor to the British Aerospace Hotol project of the 1980s. It should be capable of carrying at least 10 tonnes of payload in a standardized container to the orbital altitude of the ISS. The economics of the design depend upon the production of dozens of vehicles, each with a lifetime of around 200 return flights to orbit. As well as new engines, the design incorporates a breakthrough in overall layout, with the engines mounted on stubby wings midway along the fuselage, aircraft-style, rather than the more usual spaceplane design in which they are attached at the rear, creating huge problems of balancing the vehicle in atmospheric flight.

That fact that a vehicle such as this might not be available until the 2020s is irrelevant. The prototype SSP system proposed in the NSSO study’s Appendix B would be launched using a “large-lot purchase” of expendable launch vehicles (p. B-4). SSP will therefore not really be in the market to buy cheap spaceplane flights to orbit until the 2020s in any case. A substantial demonstrator can be launched before the economics have been solved.

Appendix C of the NSSO study analyses the business case for SSP. It notes that launch cost is the single most important factor in the economics of SSP, and that increased demand for launch to orbit could lead to a virtuous cycle of cost improvement. Obviously, as Day says, the present-day economic case for SSP is “abysmal”.

But factor in a growing space tourism industry moving along its own cost-volume development curve, a government-funded SSP demonstrator to provide confidence that there will be large-scale launch activity in the 2020s, and increasing pressure on oil, coal, and gas, and the economics could soon look very different.

What matters now is not the fact that the report was produced by an organization that “has no clout”, but whether somebody who does have clout will sit up and take notice.

Finally, Day argues that space activists have adopted the Department of Defense as an “institutional avatar”: a solution to the persistent problem of finding an organization which will take overall responsibility for developing SSP, given that neither NASA nor the Department of Energy want to do so. But if some activists do take this view, they have no authority from the NSSO study itself, which states:

“Because DoD would not want to own SBSP satellites, but rather just purchase the delivered energy as it currently does via traditional terrestrial utilities, a repeated review finding is that the commercial sector will need Government to accomplish three major tasks to catalyze SBSP development.” (p.3)

Those tasks (enumerated in the study’s recommendations on the same page) are to retire the technical risks; to facilitate the policy, regulatory and legal environment; and to become a direct early user of SSP. The onus is on the US government as a whole, not the DoD; as with traditional terrestrial utilities, the commercial sector is the natural home for the SSP industry, once it has gotten off the ground.

So while SSP is seen as having vital military applications, its civil applications are as important, if not more so. The Foreword to the study begins with a reference to the need to prevent resource conflicts in the face of increasing global populations and demands in the 21st century: this is not a military mission but rather a far broader political need.

The NSSO study adds weight to the political profile of space-based solar power as a future industrial energy source. What matters now is not the fact that it was produced by an organization that “has no clout”, but whether somebody who does have clout will sit up and take notice.