It’s Full Sail Ahead for Enthusiasts’ Spacecraft
Theorists and dreamers have imagined for decades a spacecraft whisking silently through the inky vastness of space, sailing on light rays from the sun.
Even though many studies have concluded that solar sailing could be a practical method of journeying to other stars, no government space agency has mounted a mission to see whether it actually works.
On Tuesday, the Cosmos 1 spacecraft, powered only by light reflected off a bank of 49-foot sails, is scheduled to be launched from a Russian submarine in the Barents Sea.
The project was bought and paid for by a group of space enthusiasts determined to blaze its own trail to the stars.
“No space interest group has ever built a craft and gone to space,” said Louis D. Friedman, executive director of Pasadena’s Planetary Society, which describes itself as the largest space advocacy group on Earth, with more than 80,000 members. “I’m extremely gratified. If it works, I will be even more gratified.”
Theory suggests that an infinite stream of photons, striking the reflective surfaces of the craft’s windmill-like blades, will propel it forward in space. Though the photons -- packets of light -- have no mass, each carries a tiny amount of energy that it transfers to the spacecraft when it strikes the sails.
Cosmos 1 does not use the solar wind, which is made up of ionized particles from the sun.
In the frictionless void of space, the craft would gradually gain speed, making it theoretically ideal for long journeys to the outer solar system or possibly other stars.
With a thrust just one-ten-thousandth as powerful as gravity, it won’t go fast at first. At its projected speed it would take two years to get to the moon.
But that doesn’t matter to Friedman, who likes to compare his venture to the Wright brothers’ experiments in powered flight a century ago.
“The Wright brothers flew 12 seconds and went nowhere,” he said. “I’ll be happy with any effect at all.”
Space travel has often been compared to seafaring, with the stars representing distant ports on a vast ocean of night.
Until now, however, the small vessels plying the skies have had more in common with motorized dinghies than the majestic sailing ships that explored the world’s oceans in the time of Columbus and Magellan.
The solar sail craft is different. Big enough to be visible from the Earth’s surface, it consists of eight adjustable blades in two tiers. It is one of the largest instruments ever launched into space.
The blades are made of 0.0002-inch-thick Mylar. The idea is to gather the maximum amount of light at the lowest cost in terms of weight.
Once the craft launches, it will settle into an orbit 511 miles above the Earth and will circle it every 100 minutes. The sail won’t be unfurled for four days, to allow any air in the container to leak away. If it is opened prematurely, the explosive release of air could damage the delicate spacecraft.
Once unfurled, the sail blades can be adjusted to keep the sun at the best receiving angle as the craft orbits Earth. If everything works the way it should, and the sun cooperates, the photons from the sun should lift the spacecraft into a higher orbit.
Under perfect conditions, Friedman said, Cosmos 1 might boost its orbit 31 to 62 miles over the expected 30-day life of the mission.
The idea of space-faring on sun power has been around since science fiction writers imagined claw-handed creatures from Mars landing on the National Mall.
Friedman became interested in the idea when he worked on deep-space missions for the Jet Propulsion Laboratory in La Canada Flintridge in the 1970s.
“NASA has done many studies on interstellar flight,” Friedman said. “They all end up being impossible, except for light-sailing.”
Though the drawback is the turtle-like buildup of speed, a light-sailing craft has several advantages over conventional spacecraft. Because it gets its power from the sun, it doesn’t have to carry fuel. Further, because the sun supplies continuous power, the craft can, over a period of years, reach speeds up to 100,000 mph, six times as fast as the space shuttle.
Therein lies the allure, and the challenge, Friedman said.
He wrote a book on the subject, “Starsailing: Solar Sails and Interstellar Travel.”
After leaving JPL in 1980 to form the Planetary Society along with famed astronomer Carl Sagan and former JPL director Bruce Murray, it was one of the ideas he took with him.
Bringing the idea to fruition has not been easy. The Planetary Society does not have its own launch facilities, or the budget to build its own space vehicles. So the idea sat on Friedman’s desk until the end of the 20th century.
“Nobody could solve the problem of a practical, low-cost flight,” he said.
With the end of the Cold War, however, the Soviet Union’s space program suddenly became a budgetary orphan. Russian scientists began looking outside their borders for work.
In 1999, Viacheslav “Slava” Linkin, former chief scientist in Russia’s Planetary Science Lab on Mars missions, approached Friedman with the idea of using a Russian rocket to launch a solar sail spacecraft built in Russia but paid for with American money.
“I said, ‘You can get a launch vehicle and build a spacecraft for how much?’ ” Friedman said.
The figure was about $4 million, incredibly cheap for a space project, but still a lot of money for a society of hobbyists (whose ranks also include many space scientists).
Luckily, this was at the height of the Internet boom, when all kinds of far-out, even crackpot ideas could attract millions of dollars. Major contributions came from Cleveland philanthropist Peter Lewis and Cosmos Studios in Ithaca, N.Y., a science entertainment and Internet company founded by Sagan’s widow, Ann Druyan.
Druyan said she felt a mandate “to carry on the work of Carl Sagan.”
The solar sail project was a natural extension of that work, she said. “What’s more mythic than becoming riders of light? I saw the project as my little Taj Mahal for Carl Sagan.”
Getting the project off the ground, however, presented problems big government space agencies didn’t have to worry about. Friedman at first had trouble getting a visa to travel to Moscow, where the mission will be controlled.
Some of the first signals from the spacecraft as it orbits the Earth will be captured by a seat-of-the-pants, portable tracking station in the Marshall Islands consisting of a computer, antenna and receiver.
The project’s modest nerve center is a small cottage behind the Planetary Society’s headquarters with a sign over the door that says, “Cosmos 1.”
When money ran short, project managers had to make compromises, some on the craft itself.
“We have a very good spacecraft ready to go,” Friedman said. “Still, we’ve had to cut a lot of corners.”
On the other hand, the project has had its share of lucky breaks. The only way managers were able to afford the rocket -- a conventional three-stage ICBM -- was through the arms control treaties requiring the United States and Russia to reduce their nuclear arsenals. If the rocket wasn’t being used to launch the solar sail, it could have been destroyed.
The spacecraft was built by Russia’s Lavochkin Assn., a leading maker of spacecraft. The Space Research Institute of the Russian Academy of Sciences made the electronics.
“The big uncertainty will be if everything works,” Friedman said. “You computer-model, but there’s no way to simulate how the structure will stabilize in space. It could wrap up and twist and vibrate and flutter.”
Increasing the anxiety of all concerned with the project was the failure of a suborbital flight test in 2001. Friedman says he doesn’t think the problem will repeat, “but you’re always nervous.”
It’s hard to predict what the historical significance of the flight might be. “I love to dream about the Wright brothers’ experience,” Friedman said. “But there was a decade of failure before the Wright brothers. We may be a historical footnote.”
On the other hand, the Cosmos team may be remembered as Space Age pioneers.
“We took the leap and said let’s go,” Friedman said.
He said that if the mission were successful, they hoped nations that had long had solar sailing projects on the drawing boards would start looking at using the technology for flights beyond the solar system.
Those deep-space missions will require the development of powerful lasers to provide a light source as the light from the sun fades in the distance. Friedman estimates it could take 100 years to build a laser that potent.
But Druyan said making a first step would help recharge a flagging spirit of exploration.
“Our society desperately needs this,” she said. “This is a pessimistic moment in history. We’re going to light up the world.”
