A New Era in Space

In the lead-up to the launch of the last space shuttle, "Atlantis", I've been seeing a number of articles on the general theme of an era ending. This week's Economist went so far as to suggest it marks the "End of the Space Age." I sincerely hope they are wrong, and not just because I have followed the US space program avidly since before the first moon landing, but also because of my primary focus on energy. Most of the resources of the solar system, including most of its energy resources, lie outside the earth's atmosphere. To choose a relevant example, space solar power (SSP) might not contribute significantly for decades, but it still looks like an important option for ensuring that energy limits don't constrain our long-term prosperity after the ages of oil and coal wind down.

One presentation that I still recall vividly from the many meetings involved in the economic review of NASA's "Fresh Look" approach to SSP in the 1990s, and from my time on NASA's oversight committee for SSP, dealt with the crucial role of a low-cost, high-frequency launch system in putting the components of solar power satellites into orbit affordably. Even then, it was clear that the current shuttle was not that system. It was equally clear that the traditional alternative of disposable rockets couldn't come close to the $ per pound-on-orbit threshold required. He was proposing a second- or third-generation system using unmanned reusable cargo vehicles that would land like airplanes. This was before the recent advances in drone aircraft.

I wonder what that scientist would recommend today. Perhaps he would build on some of the private spacecraft designs currently under development, such as those of SpaceX, Orbital Sciences and XCOR. However, assembling a solar power system over dozens or hundreds of launches involves very different requirements than taking tourists into space or sending astronauts back to the moon or on to Mars. In any case, without reliable access to space--traveling as passengers on Russian vehicles using a 50-year-old design doesn't count--the benefits of space will be limited to capabilities like the communications and remote sensing of today's satellites. Those are impressive enough and have transformed our world and our view of it, but they can't supply us with the concentrated energy to power cities or industries.

During the space shuttle program's 30-year history, shuttle crews accomplished extraordinary feats at tremendous risk, and sadly some of them paid with their lives. It's interesting to contemplate, as a noted space commentator did this week in Technology Review, whether the right shuttle design was chosen in the early 1970s, though mainly from the perspective of what it might tell us about what our next steps in space should be. I'm as intrigued as anyone by the prospect of resuming manned exploration beyond earth orbit, but it's hard to square the cost of that with the deep cuts that must be made elsewhere to set our financial house in order. A serious examination of the techniques and hardware necessary to deliver space resources for use on earth--now that it wouldn't have to fit an existing shuttle's capabilities--could provide a suitably pragmatic focus for NASA in the current environment.

I have a hunch that a goal of obtaining non-polluting energy from space would go a lot farther towards galvanizing the necessary public support for NASA than the next planetary mission--which incidentally might be easier to construct with the capabilities that a more nuts-and-bolts effort might create. Either way, while it's nice to look back at past achievements, I'd much rather be looking ahead to the accomplishments of the next era in space.

Observing the Sun

The topic of space exploration has gotten much media attention lately, mainly focused on the uncertain fate of future US manned space efforts in light of the cancellation of NASA's Constellation program in the administration's new budget. After the current flight of the shuttle "Endeavor" and the four remaining shuttle missions this year, the fleet will be retired and transporting astronauts to and from the International Space Station will depend on Russia, or on unproven spacecraft from commercial start-ups like SpaceX and Blue Origin. Yet without diminishing the importance of these concerns for our long-term access to space, yesterday's delayed launch of the Solar Dynamics Observatory satellite deserved more attention than it got. The SDO mission is part of NASA's "Living with a Star" program, which is aimed at expanding our knowledge about how the sun affects life on earth, with implications for energy and our understanding of the environment, including climate change.

It's hard to think of anything we take more for granted than the Sun, yet as the material on the SDO mission website explains, we don't fully understand the variability and internal mechanics of our planet's primary source of light and heat--and thus directly or indirectly of all the energy we use except for that derived from nuclear and geothermal power. Variations in the amount of solar energy the earth receives as a result of the eccentricity of our orbit around it have long been understood to influence long-term climate patterns, including ice ages, while the impact of fluctuations due to variability in the sun's actual output remains more controversial. Climate skeptics have suggested that much of the warming of the last several decades, along with the recent temperature plateau, could be related to the approximately 11-year sunspot cycle. Meanwhile NASA scientists have assessed the impact of solar variability on climate to be significantly less than that from the accumulation of atmospheric greenhouse gases. SDO should improve our understanding of solar variability and its consequences here on earth. (I should mention that observed recent short-term variability of a few Watts per square meter isn't sufficient to have a noticeable effect on the power output of solar panels.)

The more immediate energy concern that SDO should help to clarify is the risk that currently-unpredictable solar activity, including strong solar flares and resulting geomagnetic storms, poses to power grids--smart and otherwise--and communications equipment on earth and in orbit. At the extreme, a solar flare of the magnitude of the Carrington Event of 1859 could disrupt critical energy infrastructure in much the same manner as an Electromagnetic Pulse (EMP) from a high-altitude nuclear explosion. As dependent as we all are on increasingly complex and inter-connected electrical and electronic systems, anything that improves the ability of scientists to forecast a sudden spike in solar radiation could be worth its weight in gold.

NASA's capacity to conduct missions with immediate benefits on earth, such as SDO and the forthcoming Glory mission to measure key aspects of the earth's energy balance, is crucial, but then so is building on the legacy of four decades of manned spaceflight. I have distinctly mixed feelings about the altered priorities in NASA's new budget, though I'm pleased that funding for space as a whole was preserved. The possibility that this shift will spur a vibrant private space industry that could significantly reduce the cost of reaching earth orbit is exciting, because among other things that could make large-scale space solar power practical and affordable. At the same time I worry that we shouldn't cede America's preeminent position in human space exploration at a time when other nations are setting ambitious goals in this arena.

Unlimited Power?

This weekend I spoke on a panel at the International Space Development Conference in Washington, D.C. The subject of the panel was the business case for Space Solar Power, and while that might sound like a contradiction in terms to most people, it certainly wasn't for the aerospace professionals and space enthusiasts who comprised most of the audience. As alluring as I find this idea, myself, it wasn't easy staying on point that, aside from its many remaining technical challenges, this concept faces tough competition from other energy technologies with similar attributes and lower start-up hurdles. But although the "business case" for "SSP" is still not mature, capturing solar power from space deserves a place in our national R&D agenda, as an important long-term option for producing clean energy.

Since my prior involvement with it in the late 1990s, the context for the development of SSP has changed radically. Energy prices have risen to levels that were virtually unimaginable in 2000, and concerns about climate change have evolved from a scientific investigation and environmental cause célèbre to a major policy issue. Less obviously but more dramatically, a transforming military engaged in two wars sees the potential of SSP to provide a better alternative for battlefield power than delivering generator fuel to forward bases by helicopter--a reality described vividly to the audience by Colonel Paul Damphousse of the National Space Security Office, who recently returned from a second tour in Iraq piloting Marine CH-53 transport helos.

But if the need for SSP seems greater today than it did a decade ago, the obstacles to making it a reality are no less daunting. The nation's Space Shuttle fleet has suffered another loss and is on the verge of retirement, and its planned replacement is years from deployment. The private-sector space ventures that were well-represented at ISDC hold significant promise, but they already have attractive markets for telecom satellites and "space tourism." Advances in photovoltaic conversion efficiency have reduced the size requirement for a solar power satellite, but the same technology makes ground-based solar more competitive. Perhaps the biggest challenge would come from the public's perception of the risks of beaming power from space to the earth in the form of microwaves. Would this be regarded as a benign cousin of ubiquitous radio transmissions, or morph NIMBY into Not In My Sky?

Whatever the practical considerations today, it was tremendously stimulating to be with a group of people who were looking ahead with optimism to a time when SSP and other space technologies would make a larger contribution to life on earth. I was particularly intrigued by an idea from a start-up called Heliosat Corporation to use SSP to develop America's abundant shale oil resources. This plan has apparently captured the interest of the Greater Houston Partnership, and of some of its oil and gas membership. Whatever the technical and economic merits of this application, the model of using relatively small amounts of power from space to leverage a larger ground-based energy source, or to supply a unique market, looks like the right focus for the immediately-foreseeable future. Whether the first demonstration project is beaming power to a Marine Expeditionary Unit in the field or to a remote oil project, no one will invest the kind of money necessary for SSP to make a serious dent in our global energy needs without first seeing the concept turned into tangible reality.