Solar Sailing Moves into the Journals

by Paul Gilster on March 13, 2014

I’m just getting started with Chris Impey and Holly Henry’s Dreams of Other Worlds (Princeton University Press, 2013), but glancing through it yesterday reminded me how long it has taken sail hardware to get into space. While Ted Cotter and Carl Wiley hoped for early experiments with sail ideas, we never got them until much later. Interesting mission concepts like JPL’s ‘gyro’ sail to Halley’s Comet did develop (although it never flew), and the Soviet Znamya deployments gave us some experience with thin membranes in space (I’ll talk about those soon), but by and large we left interplanetary exploration for the rockets.

The deep space probes and near-Earth observatories Impey and Henry cover — Viking, Voyager, Stardust, Chandra, Hubble and their ilk — gave us outstanding results but were not, until IKAROS, joined in space by alternative sail technologies. I’ll review this book in some detail as soon as I finish it, but for today let’s go back to the late 1950s, a time when Carl Wiley had already introduced solar sailing to a science fiction audience and Ted Cotter had apprised his colleagues at Los Alamos about the possibilities of a spinning sail.

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For sails were about to make their debut in the technical journals. At the IBM Watson laboratory at Columbia University, physicist Richard Garwin, although deeply involved in nuclear weapons issues at a time of serious Cold War tensions, had become taken with the advantages of traveling between planets without propellant, not to mention the continuous acceleration that would allow the minute ‘push’ of photon momentum transfer to build up to high speeds when given enough time. In a March 1958 paper in the journal Jet Propulsion, Garwin published an analysis that ends on a note of genuine optimism: “There are considerable difficulties connected with space travel, but those connected with the sail appear relatively small.”

Image: Physicist Richard Garwin in 1980. Credit: Wikimedia Commons.

Garwin’s paper surely served as the stimulus for the detailed studies that would soon emerge, many of them covered in these pages, from the likes of Robert Forward, who would be talking about not just solar sails but sails propelled by laser in short order. Carl Wiley’s 1951 article in Astounding had been surprisingly technical, showing that sails could be maneuvered by ‘tacking’, thus allowing them to move inward toward the Sun, but it would be Garwin who put the term ‘solar sailing’ into wide use in the scientific community. By 1973, NASA would be funding solar sail studies at Battelle laboratories in Ohio, and Jerome Wright’s work on sail trajectories would lead to the Halley’s Comet mission concept, a spin stabilized heliogyro configuration using twelve 7.5 kilometer long blades of thin film.

Solar-electric propulsion won out over the heliogyro, but sharply rising cost estimates ultimately killed the entire rendezvous mission. It’s worth mentioning, since we’ve been looking at early sail pioneers this week, that the heliogyro concept itself had been developed in the 1960s by Richard MacNeal (Astro Research Corporation). The design was particularly interesting in this timeframe because it seemed to solve the challenging issues of deployment — a heliogyro would simply unroll each individual blade, as Colin McInnes explains in his Solar Sailing: Technology, Dynamics and Mission Applications (Springer, 2004). The work also led to the characterization of a wide range of thin sail films as we began to develop sail expertise.

If you’re interested in the Halley’s Comet mission, Louis Friedman’s Starsailing: Solar Sails and Interstellar Travel should be on your shelf. As to Richard Garwin, something that Enrico Fermi said surely resonates. Working with Garwin at the University of Chicago in the late 1940s, Fermi described him as the only true genius he had ever met, as recalled by fellow Fermi student Marvin Goldberger, who would himself become the head of both Caltech and the Institute for Advanced Study in Princeton. Garwin worked on nuclear arms design and in particular on the world’s first hydrogen bomb.

By 1958, the year of the solar sail paper, he was immersed in his work with IBM but also consulting for Los Alamos as well as Washington and holding down a physics appointment at Columbia. His work on how underground nuclear tests could be detected grew out of Dwight Eisenhower’s proposal of a Comprehensive Test Ban Treaty, one that failed but did lead to a partial ban in 1963.

Garwin’s later efforts on behalf of test ban issues during the Clinton administration are admirably summed up in this 1999 article by William Broad, who refers to him as a ‘onetime boy wonder’ who went on to become a celebrated physicist and passionate advocate of nuclear test bans. By then he had become chairman of the State Department’s advisory board on arms control, taking on the job with a ‘famously sharp tongue’ and bulldog tenacity. Garwin’s interests were wide, and we can be happy that one of them included a then novel way of propelling a spacecraft, a still visionary concept in 1958 but one about which research momentum was beginning to build.

Garwin’s solar sail paper is “Solar sailing — a practical method of propulsion within the solar system,” Jet Propulsion 28.3 (1958): 188-190.

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{ 3 comments }

James M. Essig March 13, 2014 at 12:25

Light sailing is an awesome approach. No need for rocket fuel, just the push of a light beam.

There should definitely be more money provided for this research. The sun is an awesome power supply at 4 x (10 EXP 26) watts. This is the equivalent power to accelerate 40 Nimitz class aircraft carriers to 86.7 percent of light-speed every second.

There are enormous energy sources throughout our universe which could be used in principle to provide beams. I was just reading about 40 billion solar mass black holes or ultra-massive black holes. Some of these Bad Boys may be spinning at nearly the speed of light.

Beamed energy seems like a great idea.

ljk March 13, 2014 at 15:06

Today is the anniversary when the European Space Agency’s Giotto probe flew by Comet Halley in 1986 and returned the first close up and clear images of a comet’s nucleus:

http://sci.esa.int/giotto/

The United States opted out of this once in a lifetime event under the presumption that not exploring the most famous comet in human history would save some money. As much as it would have been nice to have NASA develop that solar sail concept for an American Halley probe, I sometimes have to wonder if their focus on “exotic” methods for propulsion assisted in the comet not being explored at all by an American component (Russia and Japan also explored Halley with more conventional space technology methods).

Do not worry, I am not trying to put down solar sails, I just wish we had sent a mission to Halley during its last pass by Earth. Hopefully we will be a bit smarter in 2061.

Here is a link to a 1978 paper on the solar sail comet probe concept, though you need permission to proceed further:

http://arc.aiaa.org/doi/abs/10.2514/3.55794

Here is a nice in-depth article on Comet Halley Armada by Andrew LePage written in 2011 which includes some NASA article of the sail concept:

http://www.thespacereview.com/article/1798/1

Marcel Williams March 13, 2014 at 20:46

Lightsails could be used to routinely transfer meteroids up to 1000 tonnes to one of the Earth-Moon Lagrange points for the commercial production of oxygen, water, carbon, and iron for extraterrestrial utilization.

Lightsails could also be used to transport large space stations– that are assembled and lunar or meteoroid radiation shielded at the Earth-Moon Lagrange points– to orbits around Mars, Venus, Mercury and the asteroid belt.

There should be a lot more funding for lightsail research, IMO.

Marcel

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