To the skeptical observer, the notion that electricity generated in space could power Earth-based civilization likely evokes the same incredulity as a work of far-fetched science fiction. It shouldn’t. The concept is backed by substantial technical merit and sound strategic imperative. With proper financial support and political will, a space-based solar power (SBSP) system could be achieved within the mid-term future – perhaps the 2050s – using technologies and launch capabilities that are maturing today. Its benefits would be tremendous: clean, renewable energy for the world’s entire population; massive, reenergizing growth catalyzed in the space and manufacturing sectors; enormous avenues opened for global partnership, collaboration, and engagement in the space domain.
None of this, however, mean it’s a good idea. In a safe and regulated space environment, SBSP has attractive technical, economic, and strategic appeal. But that isn’t the environment of today, nor is it likely to be that of the future. The consequences of deploying an SBSP system in an increasingly contested and competitive space regime are significant – outweighing the value it could deliver.
There are no technical challenges that necessarily preclude the construction of an SBSP system. Most architectures call for the deployment of satellites of massive size and complexity in geostationary orbit (GEO) around the Earth. Using enormous solar arrays, they would collect energy from the Sun and send it back to stations on Earth through highly focused beams. A single power-collecting satellite might be as wide as 7 kilometers across; the transmitting aperture alone would likely be a kilometer across. Assembly of a single satellite would require something on the order of 400 to 800 launches.
This is doable, though it’d be by far the most significant and costly national project the United States has ever undertaken. The International Space Station took nearly a decade and hundred billion dollars to construct; an SBPS satellite, orders of magnitude larger, would no doubt be orders of magnitude more expensive as well. The system would require the long-term investment of unparalleled amounts of national treasure and resources.
And, it would only take a single kinetic strike by a space-denial weapon to be destroyed, crippling the system and creating unprecedented amounts of debris which would persist in the valuable GEO plane for generations. The DoD’s growing cognizance of vulnerabilities inherent in large space-based platforms is telling, as is its impetus toward the development of disaggregated constellations of small satellites. In an era when space is no longer a “sanctuary,” large and complex space systems have become distinct strategic liabilities.
Russia and China have already demonstrated their capability to strike objects in GEO with pinpoint precision using kinetic weapons. It is not unreasonable to predict that other potential adversaries – Iran, for example – could develop rough capacity to do the same by mid-century. It is dangerously imprudent to assume that space-based strategic systems which provide asymmetric advantages – communications, PNT, and remote sensing satellites – wouldn’t be principal targets in a future conflict. It’s an established part of our competitors’ doctrines. Just as airports, railways, and factories are infrastructure with wartime value, so too would be our SBSP system. For any enemy, countering a capability that provides the United States total energy security, for which the country has invested untold sums and around which the country’s space industry and efforts are organized and rallied, would surely be a top priority.
Such is the unfortunate nature of the new space regime. It’s a reality we nonetheless face. Extraordinarily complex, costly, and capable space systems may be easily destroyed by relatively cheap, unsophisticated, and proliferating weapons. Until some means of active defense for satellites is developed and deployed, we cannot continue to justify the cost of or reliance upon increasingly vulnerable technologies. Nor can we afford to place bets, however well intentioned, that space will forever remain untouched by conflict. It’s no small wonder the DoD is divesting from large space platforms.
The specter of war should never inhibit bold projects or large investments. Yet any undertaking as massive as an SBSP system should be tempered by risks involved and informed by the circumstances and challenges it’d face. Conventional SBSP architectures are not suited for the contested space environment, and the notion of kilometers-wide structures in GEO runs entirely diametric to our evolving doctrines of space resilience and security. Other possibilities, such as small-satellite SBSP constellations, would contend with different yet equally serious challenges: space congestion and growing orbital debris, for example. Considering that, the vast amounts money and energy that’d go into SBSP would be far better served invested in something less vulnerable, more guarded and more guaranteed, if less revolutionary.