As Cosmos 1 demonstrated, launching solar sails isn't always easy. The Planetary Society's sail perished thanks to a malfunctioning Volna booster not long after launch in 2005. When NASA attempted to launch its NanoSail-D in 2008, a problem aboard the Falcon 1 booster destroyed the craft. And when the agency launched the backup, NanoSail-D2, in December of 2010, the CubeSat-based sail failed to eject from the FASTSAT satellite it was aboard. Just when all seemed lost, NanoSail-D2 ejected on its own on January 17, 2011 and deployed its sail soon after. Now we're looking at a new Planetary Society venture called LightSail-A, which grows out of the NanoSail-D project and, according to news that should be firmed up tonight, should be ready for launch in the near future. As with Cosmos 1, the funding for LightSail-A was raised from private sources and Planetary Society membership dues, with the spacecraft itself being built by Stellar Exploration Inc. out of San Luis Obispo, CA. With...

We're coming up on the tenth anniversary of Centauri Dreams, and it doesn't surprise me even remotely that two of the earliest stories I ever wrote for the site involve solar sails. August 17, 2004's Solar Sail Test by Japan talks about the Japanese Institute of Space Astronautical Science testing sail deployment strategies, and the August 14 entry, Cosmos 1 Solar Sail Closer to Launch, briefly describes the privately funded sail that was developed by The Planetary Society's efforts, with financial contributions from members and major backing from Ann Druyan's Cosmos Studios. I've been fascinated with space sailing since first encountering the notion in 1960s-era science fiction, particularly Clarke's "The Wind from the Sun" and Cordwainer Smith's "The Lady Who Sailed the Soul." What I lacked back then, though, was an appreciation for the challenge posed by the rocket equation, which demands so much more propellant the faster you want to go. Space missions demand huge mass ratios...

We have interesting solar sail news coming up later this week, so it seems a good time to lead into it with some thoughts on NASA's early solar sail work. For the theoretical work for a sail rendezvous with Halley's Comet was well along in the 1970s, when Louis Friedman, later a founder and executive director of The Planetary Society, led what would become the first space agency attempt to develop an actual sail mission. Friedman's interest in and commitment to sail ideas will become apparent as this week progresses and we look at other sail designs. Much of the impetus for a NASA sail study in the 1970s -- a $4 million effort at the Jet Propulsion Laboratory in 1977 and 1978 -- can be traced back to Jerome Wright, an engineer at the Battelle Memorial Institute in Ohio. In his book Starsailing: Solar Sails and Interstellar Travel (John Wiley & Sons,1988), Friedman recalls a meeting of the Advanced Projects Group at the Jet Propulsion Laboratory in which he learned about Wright's...

For those wanting to dig deeper into Alan Mole's 1 kilogram interstellar colony probe idea, the author has offered to email copies of the JBIS paper -- write him at RAMole@aol.com. For my part, writing about miniaturized probes with hybrid technologies inevitably calls to mind Freeman Dyson, who in his 1985 title Infinite in All Directions (Harper & Row) discussed a 1 kilogram spacecraft that would be grown rather than built. Here's Greg Matloff's description of what Dyson whimsically called 'Astrochicken': Genetically engineered plant and animal components would be required in Astrochicken. Solar energy would power the craft in a manner analogous (or identical) to photosynthesis in plants. Sensors would connect to Astrochicken's 1-gm computer brain with nerves like those in an animal's nervous system. This space beast might have the agility of a hummingbird, with 'wings' that could serve as solar sails, sunlight collectors and planetary-atmosphere aerobrakes. A chemical rocket...

'Sundiver' maneuvers are surely the most extreme events to which we could subject a solar sail. To my knowledge, it was Gregory Benford who first came up with the term -- he mentions in Fantasy & Science Fiction that he passed the coinage on to David Brin when Brin was working on the book that would bear its name (Sundiver, published in 1985, would be the first volume in Brin's Uplift Saga). But Benford credits Brin with the actual concept, which he needed to make his plot work, so it seems best to give credit to both writers for an idea both went on to explore, Benford not only in fiction but in scientific papers as well. The maneuver is straightforward if breathtaking. Benford explains it in terms of a carbon sail being deployed in low Earth orbit and then launched into deep space by microwave beam: Consider the sundiving sail. Approaching the Sun turned edge-on (to prevent the increasing flux of sunlight from pushing against its fall), the carbon sail heats up. At closest...

What got me thinking about French influences on early solar sail work in Russia yesterday was the realization that science fiction was much stronger in Europe, and particularly France, in the latter part of the 19th Century than we Americans might realize. Hugo Gernsback to the contrary, the genre did not emerge in 1926 with the appearance of Amazing Stories, nor did key early texts like Mary Shelley's Frankenstein launch the genre in England. Brian Aldiss would probably argue with this (see his Trillion Year Spree, 1973), but I agree with Brian Stableford in seeing a true genre emerging first on French soil. Whether you agree or not, have a look at Stableford's essay The French Origin of the Science Fiction Genre, where I find this in reference not only to Verne but writers like George Sand (Laura: voyages et impressions, 1865) and Camille Flammarion (Récits de l'infini, 1872): These works were sometimes referred to by contemporary commentators as examples of roman...

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...

Carl Wiley, the prescient engineer who offered an early description of solar sails in "Clipper Ships of Space" (Astounding Science Fiction (May, 1951), was not the first to look into sail propulsion, but he was one of the more visible. Konstantin Tsiolkovsky's thinking on the matter in the 1920s was not widely circulated, and it may be that John Desmond Bernal, a political activist and professor at Cambridge and, later, the University of London, was Wiley's primary forerunner as far as public awareness of sail ideas is concerned. In The World, the Flesh & the Devil (1929), Bernal looked at the propulsive possibilities in light: However it is effected, the first leaving of the earth will have provided its with the means of traveling through space with considerable acceleration and, therefore, the possibility of obtaining great velocities - even if the acceleration can only be maintained for a short time. If the problem of the utilization of solar energy has by that time been solved,...

If you're interested in solar sails and find yourself in California, a stop by UC Riverside's Tomás Rivera Library should be worth your time. There you will find the Carl A. Wiley collection on solar sails, containing books, manuscripts and various other materials related to sail technologies. Wiley was an aeronautical engineer who wrote the first detailed article on solar sails to reach a wide audience. Evidently concerned about the venue -- Wiley's article had been accepted by John Campbell's Astounding Science Fiction, which some of his colleagues might not have taken seriously -- he chose to write under the pseudonym 'Russell Saunders.' Finding Wiley's papers at Riverside is perhaps no surprise, given that this is the home of the Eaton Collection of Science Fiction & Fantasy, 'the largest publicly-accessible collection of science fiction, fantasy, horror and utopian literature in the world.' Pulp magazine enthusiasts like myself will note that the archive houses full runs of many...

For years now Pekka Janhunen has been working on his concept of an electric sail with the same intensity that Claudio Maccone has brought to the gravitational focus mission called FOCAL. Both men are engaging advocates of their ideas, and having just had a good conversation with Dr. Maccone (by phone, unfortunately, as I've been down with the flu), I was pleased to see Dr. Janhunen's electric sail pop up again in online discussions. It turns out that the physicist has been envisioning a sail mission to an unusual target. Let's talk a bit about the mission an electric sail enables. This is a solar wind-rider, taking advantage not of the momentum imparted by photons from the Sun but the stream of charged particles pushing from the Sun out to the heliopause (thereby blowing out the bubble' in the interstellar medium we call the heliosphere). As Janhunen (Finnish Meteorological Institute) has designed it, the electric sail taps the Coulomb interaction in which particles are attracted or...

If we can use solar photons to drive a sail, and perhaps use their momentum to stabilize a threatened observatory like Kepler, what about that other great push from the Sun, the solar wind? Unlike the stream of massless photons that exert a minute but cumulative push on a surface like a sail, the solar wind is a stream of charged particles moving at speeds of 500 kilometers per second and more, a flow that has captured the interest of those hoping to create a magnetic sail to ride it. A 'magsail' interacts with the solar wind's plasma. The sailing metaphor remains, but solar sails and magsails get their push from fundamentally different processes. Create a magnetic field around your spacecraft and interesting things begin to happen. Those electrons and positively charged ions flowing from the Sun experience a force as they move through the field, one that varies depending on the direction the particles are moving with respect to the field. The magsail is then subjected to an opposing...

How do we go about using photons to accelerate a spacecraft to a substantial percentage of the speed of light? Ten percent of c ought to do -- it gets us to Alpha Centauri with a mission time of 43 years and would allow us to at least send flyby probes into that system, with the promise of larger decelerating probes as new technologies became available. After yesterday's post on Young Bae's photonic thrusters, I went back and read his 2012 paper "Prospective of Photon Propulsion for Interstellar Flight" (reference at the end). 10 percent of lightspeed is indeed the minimum he chooses. It works out to 30,000 kilometers per second. Back in the 1950s, the German scientist Eugen Sänger talked about a 'photon rocket' as a way of reaching the stars, but his design called for annihilating electrons and positrons and using the gamma rays thus produced for thrust. The idea stumbled over the problem of controlling this kind of exhaust stream, for gamma rays penetrate anything we use to contain...

A recent article in Popular Mechanics about Young K. Bae's work on laser propulsion is generating some buzz, enough that I went back to look at the 2008 report Bae did for the NASA Institute for Advanced Concepts. Actually there are two reports, a Phase I and a later Phase II (with additional funding) on the topic of "A Contamination-Free Ultrahigh Precision Formation Flight Method Based on Intracavity Photon Thrusters and Tethers." Bae was interested in spacecraft formation flight down to precisions of mere nanometers. The idea relates to missions that would use multiple spacecraft to study astronomical phenomena. In fact, setting up a proper configuration would allow the study of biosignatures in the atmospheres of terrestrial exoplanets, using the technique of interferometry. Here the image produced has a resolution equal to that of a telescope as large as the maximum antenna separation, but the spacecraft involved have to maintain their alignment. Both ESA (with the Darwin...

by Charles Quarra Charles Quarra tells me that like many kids who grow up dreaming about the stars, he realized early on that a career in physics would make sense. A book-filled childhood helped fix this focus, especially Carl Sagan's The Cosmic Connection and Peter Nicholls' The Science in Science Fiction. Charles went on to get a Physics B.Sc degree from Universidad Simón Bolivar in Caracas in 2006, but adds "pursuing it as a career turned out to be less satisfying as time went on. I've also been programming most of my life, so a transition to a software development career felt almost too natural for me, which I've been doing since moving to Panamá in early 2008." His interest in space propulsion and exploration, though, remains strong, as evidenced by the paper he presented at Starship Congress in Dallas, which looks at building a chain of stable equidistant laser relays to provide beamed power for interstellar spacecraft. In the post below, Charles summarizes what he has...

I'm always on the lookout for practical ways to use solar sails. We think long-term here and interstellar flight is the topic, but the other side of that coin is that we need to see incremental progress made that builds toward a significant human presence in space. Creating the installations to send powerful microwave or laser beams to interstellar sailships will involve mastering all kinds of needed objectives starting with getting large payloads to low-Earth orbit cheaply and building plentiful expertise in moving supplies at interplanetary distances. Sails can go to work for us here, and before we get to that level, we can chart a path of development with clear, practical uses that companies and governments can support. Yesterday I mentioned Les Johnson's talk at Starship Congress in Dallas, in which he described ongoing sail efforts and noted that NASA's Sunjammer sail was partly sponsored by the National Oceanic and Atmospheric Administration. Early warning for solar storms is a...

Several years ago in Italy Les Johnson told me that he had once had the coolest job description in NASA. And I remember those days in the early 2000s when I was just beginning to investigate interstellar issues, and Les, working at Marshall Space Flight Center in Huntsville, carried a NASA business card describing him as 'Manager of Interstellar Propulsion Technology Research.' These days Les' title is not quite as exotic but he's involved as ever with solar sails. Les is also an author, and among his many books is one I recommend to anyone trying to learn more about solar sails. Written with Gregory Matloff and Giovanni Vulpetti, Solar Sails: A Novel Approach to Interplanetary Travel (Copernicus, 2008) reviews the history of the concept going back to James Clerk Maxwell, who pointed out in his monumental work on electric and magnetic fields that photons can impart force to an object they encounter. Konstantin Tsiolkovsky and the Latvian scientist Friderikh Arturovich Tsander went on...

The evening after Jim Benford's Starship Congress talk on his solar sail lab work at the Jet Propulsion Laboratory, a small group of sail advocates joined him in the Hilton Anatole's top floor restaurant to talk over the issues. Benford is organizing Project Forward, named after the legendary Robert Forward, as an Icarus Interstellar effort to further refine the interstellar beamed sail concept. Asked to name the biggest problem areas for sails, the group came up with several, but at the top of the list was deceleration. How do you slow a beamed sail down when it arrives at its target? A number of possibilities suggest themselves and at this point all of them are completely theoretical. Forward himself wrote up a 'staged sail' concept, in which the outer ring of the sail detaches as the star is approached, moving ahead of the inner ring and attached payload. The Earth-based beamer bounces the laser off the larger sail ring, which reflects it back to the smaller sail and slows it for...

Low clouds had descended upon Dallas when I landed at Love Field, and by the time I got to the Hilton Anatole for the Starship Congress being hosted by Icarus Interstellar, the city outside was swathed in mist. This was last Wednesday evening, and it was late enough by the time I had dinner that a quick stroll through the cavernous facility was about all I wanted to do before getting some sleep. The Anatole, though, was gorgeous, filled with paintings and sculpture, some of which (two statues of elephants) became helpful landmarks as I learned to navigate the place. Image: An atrium at the Hotel Anatole at night, one of two, connected so that inveterate walkers like myself could make figure-eight circuits by following the room corridors on any floor. Starship Congress was a roaring success, the kind of thing that happens when you put people with passionate interests in the same place who usually know each other only through email or by reputation. Saving the day for me on day one was...

The British geneticist and biologist J.B.S. Haldane has left us with one of the more memorable lines about scientific inquiry, one that draws on the richest of all of Shakespeare's plays for its punch. Hamlet tells Horatio that there are more things in heaven and Earth than are dreamt of in his philosophy (Act 1, Sc. 5), a thought Haldane adapts in the service of intellectual surprise. In his collection Possible Worlds and Other Essays (1927), he writes: I have no doubt that in reality the future will be vastly more surprising than anything I can imagine. Now my own suspicion is that the universe is not only queerer than we suppose, but queerer than we can suppose ... I suspect that there are more things in heaven and earth than are dreamed of, or can be dreamed of, in any philosophy. We can imagine Olaf Stapledon nodding as he read those lines. Haldane sketched out a human history covering the coming 40 million years in his essay "The Last Judgement," one that Stapledon drew on in...

What we hope to learn from early experiments with the electric sail is whether keeping a steady electric potential on long tethers will give us enough interaction with the solar wind to make for viable propulsion. ESTCube-1, launched earlier this week, is a step in that direction. Even though it uses but a single 10-meter wire, its rotation rate should change once the tether is fully extended and powered up. Bear in mind that ESTCube-1 is deep within the Earth’s magnetosphere, so the charged particles it will be interacting with are not from the solar wind, but a proof of principle is sought here that could make electric sailing a candidate for outer system-bound spacecraft. It’s important to distinguish between solar sails and their electric counterparts. The Japanese IKAROS sail, successfully tested, showed that solar photons could impart momentum to a thin sail, as our experience with early satellites had already demonstrated. The beauty of sailing in any form is that we leave the...