Photo by Rick Sternback, © The Planetary Society
The cosmic game changed forever in 1992. Before then, logic told us that there had to be other planets besides the nine (if you still count poor Pluto) in our solar system, but until that year, when two astronomers detected faint, telltale radio signals in the constellation Virgo, we had no hard evidence of their existence. Now, 17 years later, thanks to advancing means of astronomical detection, we are fairly certain of more than 300 “exoplanets,” including a five-planet system that orbits star 55 Cancri in the constellation Cancer, 41 light-years away. Stars, of course, are too hot to support life, so wherever life might exist in the universe, it has to be on planets or moons that are warmed, but not incinerated, by the stars they travel around. Well, one of 55 Cancri’s five planets may be temperate enough to support life.
The exponential vastness of the universe tells us—if we apply reasonable, conservative inference—that there have to be billions more exoplanets besides the hundreds now confirmed. Simple back-of-the-envelope arithmetic will demonstrate the new inconceivability of our being the only intelligent beings in the universe. No, the Others are not about to come here, and we’re not about to go to them—not in person—but they’re there. And yet, even so, humankind’s sense of itself here on Earth has yet to undergo the sea change suggested by the facts.
Should we feel encouraged by our new awareness? Perhaps diminished? Suffice it to say humanity hasn’t given it a thought. Most of us, instead of looking outward, have spent the past 17 years sewing ourselves into an earthbound straitjacket of cell-phoned, instant-messaged, Internetted connectedness that has made the species more solipsistic than ever. Forget jihad and global warming; we may just talk ourselves to death. One almost wonders whether all our endless communication about nothing, this clinging together, isn’t some fearful, subconscious response to our new knowledge that other civilizations have got to be out there, perhaps some that can run celestial rings around us. Are we afraid of what we newly know? Is that why we give it no serious reflection?
Last spring, NASA scored a big success when its Phoenix probe landed on Mars, dug a little trench, and uncovered ice, with all its life-sustaining implications. And yet, however significant this achievement is, the agency is still decades away from sending humans to that planet—and well past the time by which it was once expected to have sent them.
Having had the shuttle, an orbiting millstone, around its neck for almost 30 years, NASA is now supposed to move on to a new generation of spacecraft that will take us back to the moon—it’s been 37 years since anyone set foot there—and then to Mars. This was President Bush’s Vision for Space Exploration, propounded in 2004, and it now belongs to President Obama. Although he started his campaign with a kind of anti-space policy that was a footnote to his education plans—he would delay the development of new craft for five years and spend the savings on the nation’s schools—Obama soon enough got with the existing program and called for efforts to “expedite the development of the Shuttle’s successor systems.”
Between the shuttle’s planned retirement in 2010 and a new system’s development, the U.S. government will have to rely on the old Soviet Soyuz to get crews and supplies up to the International Space Station. Worse, the first of our own new launch vehicles, Ares 1, is already beginning to look unreliable, at least in tests. American politicians now mostly avoid the old conditional trope “If we can put a man on the moon”—because we can’t, not anymore.
The Vision for Space Exploration really doesn’t have any; nor does NASA. In 2002, the agency shut down its Breakthrough Propulsion Physics program, whose scientists had been allowed to brainstorm such far-out notions as wormholes and warp drives; five years later, the agency closed its Institute for Advanced Concepts, a less mind-blowing outfit but one that also encouraged thinking light-years down the road.
Even the most spectacular unmanned successes of the American space program—from the Voyager probes of the ’70s to the Galileo and Cassini missions of the ’90s—seem to belong to a fading worldview. A desire to explore, even by mechanical proxy, is now a self-indulgence to be resisted, since the end result would only be the imperial spreading of that pollutant known as humankind. In the new view, people have made such a mess of things here that we have no right to any more of the universe, and certainly not to a “backup planet,” which some space enthusiasts have suggested as the ultimate hedge against environmental catastrophe on Earth.
But just suppose—it’s reasonable to—that such a place exists. Is it then remotely reasonable that not a particle of the Vision for Space Exploration is devoted to sailing an earthly machine over the vast distance between here and there—either to confirm its existence or to let it know of ours?
Two groups of well-credentialed space scientists, one in California and another in Russia—mostly veterans of long-ago space triumphs by NASA and the Soviet program—believe that the first frail, shiny prototype of an interstellar flying machine has been lying on the floor of the Barents Sea since June 21, 2005.
Almost everybody seemed to detect something—a signal that the spacecraft was in orbit and ready to deploy its visionary cargo. The Volna rocket had risen out of the water, flown through the sky, and pierced the low-lying clouds. The Volna, a Soviet-era ICBM, had been refitted for peaceful duty, and on this first day of summer, it was lifting Cosmos 1 up from a Russian submarine and toward Earth orbit. If the spacecraft got there, it would deploy eight tissue-thin “blades,” 600 square meters of Mylar that would catch the sun and begin propelling the craft, on nothing but light, through humankind’s first solar-sailing voyage. The ship, beautiful as a flower or firework, would be controlled from the ground by two teams, each so small that Mission Operations Moscow was called MOM and Project Operations Pasadena was POP.
Louis Friedman, the head of the Planetary Society, the mission’s chief sponsor, and Viacheslav “Slava” Linkin, the payload and electronics man, received word in Moscow that Doppler data from the Kamchatka tracking station suggested orbital insertion. Viktor Kerzhanovich, listening from Majuro in the Marshall Islands, also detected a signal, however weak. Trackers in the Czech Republic picked up something, too. But then, nothing.
In fact, the spacecraft never made it into orbit. The Volna, that formidable Cold War sword, had proved a less than reliable plowshare, making for a failure that was bitterly beside the point: the chemically propelled brute-force rocket was the trouble, not the beautiful Icarian blades that never got a chance to be tested.
Friedman put the best face on things in a report to members of the Planetary Society and the larger space community—“We conducted the first space mission by a privately funded space-interest group”—but nearly four years later the memory of the false signals still taunts him. Solar sailing, probably the only means by which manmade vehicles will ever travel to the stars, still awaits what believers call its “Kitty Hawk moment.” Friedman continues to work in Pasadena and rack up mileage to Moscow, determined to keep his Russian-American team together, to raise another $4 million, to build Cosmos 2, and, if possible, to unfurl its silver sails before—well, a little after—this decade is out.
At 68, he remains gently and compulsively humorous, his Bronx-born voice and manner a less manic version of Mel Brooks’s. After getting his doctorate in aeronautics and astronautics from MIT, Friedman spent the 1970s in Pasadena at the Jet Propulsion Laboratory, where he was involved in the greatest of all unmanned space achievements, the “Grand Tour” of the planets by NASA’s two Voyager spacecraft. While at JPL, he also was the head of a study group that investigated the possibility of sending a solar-sailing spacecraft to rendezvous with Halley’s Comet during its once-in-a-lifetime flyby in 1986. In the end, there wasn’t time to get the mission up and running, but the project left Friedman convinced of solar sailing’s feasibility. He has hung on to the idea and kept it alive ever since he founded the Planetary Society, along with Carl Sagan and JPL’s Bruce Murray, in 1980. A natural cheerleader with a gift for colorful explanations, he remains the executive director of an organization that combines space advocacy with actual small-scale missions. “We’re not trying to be another NASA,” he says, “but we do show the value of being able to come up with clever things that interest the public, that are scientifically solid.”
Putting a microphone on Mars was one of them; alas, NASA’s Mars Polar Lander, on which the microphone traveled, perished during its descent to the Red Planet in 1999. Studying the “Pioneer anomaly” is another: TPS is funding work to explain why the last data to come back from the old Pioneer 10 and 11 space probes, launched decades ago and by now moving out of the solar system, showed slight, unexpected slowdowns by both craft. Is some physical force that we don’t know about operating at those reaches?
A test of solar sailing fits in with all of this, says Friedman: it’s of sufficient scientific soundness, and on a small enough scale, that the Planetary Society can take the lead. A wooden carriage house behind the society’s headquarters in Pasadena still bears the sign COSMOS 1: PROJECT OPERATIONS—PASADENA. It’s just waiting for a change of numeral.
“There’s no free launch,” Friedman likes to say, and the Planetary Society has wound up paying dearly for its decision to go with the Volna. The rocket’s Russian suppliers “knew they had a design problem,” but even after the flaw was discovered, Cosmos 1 got strapped onto a Volna from an old, unrepaired batch. TPS is now likely to launch Cosmos 2 on a Soyuz, the more reliable workhorse from Soviet days.
In March of 2008, I sat down in the carriage house with Friedman and two other members of his solar-sailing team: Harris “Bud” Schurmeier, the retired project manager on the old Voyager missions; and Viktor Kerzhanovich, whose long career in both Russia and America has earned him the U.S.S.R. State Prize and more than one NASA Group Achievement Award. If the Planetary Society tends to exhort its more than 50,000 members in sonorous terms, conversation in the carriage house was speculative and playful. Throughout the morning, the years fell away from the three old-timers eager to tell a visitor about how solar sailing works—and to spar a bit.
“Light has energy,” said Friedman. “That you can’t argue with.”
“More important,” said Kerzhanovich, “it has momentum.”
“Therefore it has a force,” added Friedman. “You’re using the energy of light, and the force derived thereof, to transfer momentum of light energy to your vehicle, in order to propel the spacecraft. Basically your spacecraft, your solar sail, looks like a sail, but it really is a mirror. And so it’s reflecting the light, and that reflection is where the momentum transfer occurs.” If the mirror were fixed to a wall, there would be no transfer. But in free space, with no gravity and no air pressure? You’re off to the cosmic races.
“It’s not the solar wind,” Friedman reminded me.
“Things got named wrong,” said Schurmeier. However pretty it sounds, “sailing” is really a metaphor. There is such a thing as solar wind, but as Friedman explained, “Solar wind is electrons and protons that come from the sun, and they have mass, but they go very much slower than light.”
It’s photons, not protons, that we’re talking about?
“Right,” said Friedman. “Photons have no mass, they’re all energy. You do get a force from the solar wind, but it’s about a thousand times less than the force you get from this reflection. You turn your mirror in different directions, you can point the force in any direction you want!”
Not everyone concedes even the basics. The late Thomas Gold, of Cornell’s Center for Radiophysics and Space Research, had insisted that solar sailing would never work, for the same reasons you cannot have a perpetual-motion machine: Carnot’s rule and the iron second law of thermodynamics. No machine can extract an unlimited supply of free energy from any source; a certain “degradation” has to occur. And the problem is even more fundamental than that, Gold argued: the beautiful Mylar blades of Cosmos 1, or 2, will be too splendid to function, period. With “a perfect mirror, the two temperatures”—of the sails and the sun—“will be the same,” Gold reasoned. “And it follows that the mirror cannot act as a heat engine at all: no free energy can be obtained from the light.”
Not so, countered Benjamin Diedrich in New Scientist. “Light pressure does work.” Solar sails are an “open system,” not the kind of “closed-loop heat engines” that Carnot had in mind.
The whole concept has been waiting for its trial for a century and more. Friedrich Tsander and Konstantin Tsiolkovsky, two Russian space scientists, first wrote about solar sailing’s possibilities in the 1920s, 40 years after theories were put forth as to how the tails of comets, which generally point away from the sun, actually grow from the pressure of the sun’s light.
The romantic appeal of solar sailing has ensured that its advocates consistently come from the worlds of both science fiction and science fact. An anthology of writings on the subject, published in 1990, counted Sir Arthur C. Clarke as well as Friedman among its contributors, and even hard-science writing on the subject tends to kick into utopian overdrive. In his 1992 book, Space Sailing, Jerome L. Wright, the engineer who brought the Halley-rendezvous idea to Friedman at JPL, wrote of how solar vehicles “can move us away from single use, disposable interplanetary spacecraft,” as if the latter were already on the celestial road, like SUVs we can now replace with Priuses.
Friedman doesn’t know whether interstellar flight—by machines, not humans—will occur within 200 years or 500. But “the idea that we go interstellar” is not, he says, “a hard sell.” In fact, it’s usually this possibility—connected to people’s slumbering curiosity about the chances that intelligent life exists elsewhere in the universe—that winds up exciting the greatest lay interest in solar sailing. In one of his newsletters to TPS supporters, Friedman looks toward the technology’s long-term, astral future. Once a sailing vehicle leaves the solar system, it will run out of gas—that is, sunlight—and space-based lasers, put into orbit around the planets, would have to keep beaming the necessary juice over vast distances. “Not easy,” says Friedman. “But not the province of fantasy, either.” Even 20 years ago, in his book Starsailing, he was touting one laser scheme that could get a solar-sailing vehicle with a “1-ton payload to the Alpha-Centauri system in 40 years or even a bit less.”
NASA representatives did take a late-breaking interest in Cosmos 1—a number of them showed up at TPS for the launch—and the space agency has been involved with the testing of atmospheric drag on a solar “nanosail.” They’ve even asked TPS for some collaboration. But that’s hardly the same as a full-blown test of sun-powered, ground-controlled flight in an orbit 500 miles above the Earth. The European Space Agency has walked away from the solar-sailing plans it once had, for the same reason that NASA remains uninvolved: there’s no money for testing a technology that can’t be applied, near-term, to a specific mission.
Friedman’s teams are really waiting for a first answer, not a last: whether Cosmos 2 will fly, financially and then physically. If it succeeds in getting aloft, with its sails unfurled, it will intermittently be a very bright object to the observant naked eye on Earth. But the project team will need a close-up, detailed look, not just an appreciative glimpse. They hope to record, maybe even from the International Space Station, a kind of childbirth movie that will allow them to see exactly how the sails open, and whether they operate properly or fall victim to some as-yet-unknown instability.