My Involvement with Laser Power Beaming

Geoffrey A. Landis

Beaming power by microwave from space for use on Earth, of course, was suggested by Peter Glaser in 1968, and following this suggestion there were several analyses of the possibility of beaming from space to space by microwave. In the 1980's, researchers at NASA Langley, particularly Ed Conway and Gilbert Walker, worked on the potential use of lasers for space-to-space power beaming, focussing primarily on the development of a solar-powered laser to do this. In 1989 I suggested that power could be usefully beamed by laser in the opposite direction: from Earth to space. In particular, I proposed, at the Princeton Conference on Space Manufacturing in 89, that Earth-based lasers could be used to provide power to a lunar base over the 354-hour lunar night, using the same solar arrays that were used to provide solar power during the daytime. I proposed the concept to NASA as a white-paper submitted to the "outreach" program to solicit ideas for the Space Exploration Initiative in 1990, and gave more details on the concept in a paper later published in the AIAA Journal of Power and Propulsion.

In 1991, John Rather at NASA Headquarters independently had exactly the same idea. I first met John at the Resources of Near Earth Space conference in 1991; at that time he had started advocating laser power beaming for supplying power to a lunar base, but hadn't yet published anything. We discussed our two versions of the concept there. Very shortly after that meeting, John arranged a dedicated workshop at NASA Lewis on the subject of laser power beaming for a moonbase, and within a few months the SELENE project (an acronym that originally stood for "Segmented Efficient Laser Emission for Nonnuclear Energy"-- later the acronym was changed, but the referent changed to "SpacE Laser ENErgy") was official.

The idea of using an Earth based laser to extend the life of communications satellites past battery failure developed out of my laser power for the moon analysis, also somewhat before the SELENE project began. The original paper on this was published as a paper by the International Astronautical Federation in 1989 and then reprinted in the journal Acta Astronautica; a preprint of the Acta Astronautica version of the paper was included in the SELENE pre-kickoff meeting proceedings in 1991. When I presented the concept at the 1991 Space Photovoltaic Research and Technology Conference, it got picked up by Andrew Meulenberg of Comsat Laboratories, who took it to Larry Westerlund (then vice-president of Comsat), who liked the idea and called up John Rather at NASA Headquarters to push it. It first got added the SELENE baseline plan in the December 1991 "Review of SELENE FY91 Program Results & FY92 Program Kickoff" meeting, where the concept of rejuvenating "dead" satellites was discussed in detail in my presentation.

The use of an Earth-based laser to power an electric thruster for space propulsion was first proposed, as far as I know, by Grant Logan of Lawrence Livermore Laboratories in 1988, with technical details worked out in 1989. His proposal was a bit optimistic about technology (he proposed using diamond solar cells operating at a six-hundred degrees to convert ultraviolet laser light, a technology that has yet to be demonstrated even in the laboratory, at a wavelength that will not easily transmit through the Earth's atmosphere). His ideas, with the technology scaled down to be possible with more practical, nearer-term technology, were adapted into the SELENE program.

The SELENE program was a serious research effort for about two years, but never had great support from NASA Headquarters-- the cost of taking the concept to operational status was too high, and the pay-off too far-term. With the cancellation of the Space Exploration Initiative (SEI) proposed by former US president Bush, there was no application present with enough up-front cash to fund development of the high CW power lasers and the large-aperture adaptive mirror. The SELENE project, per se, finished up around 1993, before we reached the goal of demonstrating the technology in space. However, some research is still going on at a lower level. I have some hope, for example, that in the near term we may be able to develop an array for a laser-powered aircraft demonstration.

From the beginning, both John Rather and I have envisioned the use of laser power beaming as a stepping-stone to further industrialization of space, realizing that a large-scale demonstration of power beaming is a necessary step to the development of solar power satellites. I have every hope that the technology will lead to great things.

artist's sketch of power beaming
Concept schematic showing power beaming to spacecraft and the moon

Some references on the "prehistory" of laser power beaming:

  1. G.A. Landis, "Solar Power for the Lunar Night," Space Manufacturing 7: Space Resources to Improve Life on Earth, pp. 290-296 (AIAA, 1989). Presented at 9th Princeton/SSI Conference on Space Manufacturing, May 10-13 1989
  2. G.A. Landis, "Moonbase Night Power by Laser Illumination," J. Propulsion and Power, Vol. 8, No. 1, pp. 251-254 (1992). Also in Proceedings of the Technology Workshop on Laser Beamed Power, Feb. 1991, NASA Lewis Research Center, Cleveland OH.
  3. G.A. Landis, "Satellite Eclipse Power by Laser Illumination," Acta Astronautica, Vol. 25, No. 4, pp. 229-233 (1991); paper IAF-90-053; 41st IAF Congress, Dresden, Germany, Oct. 1990.
  4. G.A. Landis, "Space Power by Ground-based Laser Illumination," IEEE Aerospace and Electronics Systems, Vol. 6, No. 6, pp. 3-7, Nov. 1991. Presented at 26th Intersociety Energy Conversion Engineering Conference, Aug. 1991, Vol. 1, pp. 1-6.
  5. G. Landis, "Photovoltaic Receivers for Laser Beamed Power," Journal of Propulsion and Power, Vol. 9 No. 1, 105-112 (1993). Presented at 22nd IEEE Photovoltaic Specialists Conference, Las Vegas NV, Oct. 1991, Vol. II, 1494-1502. Also available as NASA Report CR-189075 (1991).
  6. R. Lowe, G. Landis and P. Jenkins, "Response of Solar Cells to Pulsed Laser Illumination," IEEE Transactions on Electron Devices, Vol. 42, No. 4, 744-751 (1995).

    More references are in my scientific bibliography.