Solar sails to take flight

For decades, scientists and science fiction writers alike have floated the idea of using solar sails to propel spacecraft across vast distances. One of those advocates was the late astronomer Carl Sagan. In honor of Sagan's 75th birthday, the Planetary Society, which Sagan co-founded in 1980, announced a series of forthcoming solar sail experiments. Funded by a wealthy, and anonymous, donor, the group will launch their LightSail system three times over the next few years. The first two missions will be in Earth orbit, and the target of the third is about 900,000 miles away, in a popular "hang out" zone for traditional satellites collecting scientific data. From the New York Times:
 Images 2009 11 09 Science 10Solar-1 Popup The (actual sail) is made of aluminized Mylar about one-quarter the thickness of a trash bag. The body of the spacecraft will consist of three miniature satellites known as CubeSats, four inches on a side, which were first developed by students at Stanford and now can be bought on the Web, among other places. One of the cubes will hold electronics and the other two will carry folded-up sails, (Planetary Society co-founder Louis) Friedman said.

Assembled like blocks, the whole thing weighs less than five kilograms, or about 11 pounds. "The hardware is the smallest part," Dr. Friedman said. "You can't spend a lot on a five-kilogram system."

The LightSail missions will be spread about a year apart, starting around the end of 2010, with the exact timing depending on what rockets are available. The idea, Dr. Friedman said, is to piggyback on the launching of a regular satellite. Various American and Russian rockets are all possibilities for a ride, he said.

Dr. Friedman said the first flight, LightSail-1, would be a success if the sail could be controlled for even a small part of an orbit and it showed any sign of being accelerated by sunlight.

"Setting Sail Into Space, Propelled by Sunshine"


  1. The Planetary Society has tried twice before to launch a solar sail, in 2001 and 2005, but both attempts were thwarted when the Russian ICBMs used as launch vehicles failed to reach orbit. NASA, working with the Planetary Society, then tried to launch their own nano-sail on SpaceX’s Falcon 1 mission, which also failed to reach orbit.

    I’m not saying I believe in curses, but I wouldn’t want my mission to be the one they choose to piggyback Lightsail-1 on.

  2. The link is broken.

    I’d like to know how large the sail is when it’s unfurled. Don’t these things have to be huge to be of any use at all?

  3. Funded by a wealthy, and anonymous, donor…

    My guess is an eccentric billionaire with one thing on his mind: SPACE YACHT.

  4. I’ve been reading a lot about these ideas, and I think it’s great. But what about space debris and micro asteroids? Surely the sails would end up like a Swiss Cheese?

    As for the anonymous millionaire, I bet it is Tom Cruise.

  5. the target of the third is about 900,000 miles away, in a popular “hang out” zone for traditional satellites collecting scientific data.

    Just say “Lagrange point” and be done with it. This isn’t a mainstream news site, you don’t have to dumb everything down into third-grade lingo before us plebs can understand it. I’m sure anyone who doesn’t get it right off the bat is more than capable of navigating wikipedia.

  6. The applications for clusters of these in controllable formations are mind-bending.

    Short of the ability to throw up a light-second wide field from the maw of your massively god-like culture ship; shoals of solar powered mirrors swimming in the night will more than suffice as groovy tech.

  7. Funded by a wealthy, and anonymous, donor, the group will launch their LightSail system three times over the next few years

    Why build only one when you can build three for three times the price? ;]

    (And I second #9)

Comments are closed.