Our Solar Sail

Tiny Spacecraft, Big Design

LightSail is a CubeSat. These tiny spacecraft often hitch rides to orbit aboard rockets carrying bigger payloads. CubeSats have standard unit sizes of 10 centimeters per side. They can be stacked together—LightSail is a three-unit CubeSat about the size of a loaf of bread.

Once in space, LightSail’s solar arrays swing open, revealing the inside of the spacecraft. Four tape measure-like metal booms slowly unwind from storage, unfolding four triangular, Mylar sails. Each sail is just 4.5 microns thick—one-fourth the thickness of an average trash bag.

Three electromagnetic torque rods and a momentum wheel orient LightSail in space. Ground-based lasers will measure the effect of sunlight on the sails. As LightSail breezes around the Earth, its shiny sails will be visible from the ground. We’ll organize viewing campaigns to show people where to look.

LightSail and engineering team members — LightSail team members Alex Diaz (left) and Riki Munakata (right) prepare the spacecraft for a sail deployment test.

The Mission

Sailing In Space

In May 2015, our LightSail 1 spacecraft hitched a ride to space aboard an Atlas V rocket for a shakedown cruise. Our orbit didn't carry us high enough above the Earth's atmosphere for solar sailing, but we tested our deployment sequence and captured a picture of our unfurled sails.

LightSail with solar sails deployed — LightSail 1 captured this image of its deployed solar sails in Earth orbit on June 8, 2015.

In 2017, LightSail 2 will be enclosed within Prox-1, a small satellite developed by the Georgia Institute of Technology (Georgia Tech) to autonomously inspect other spacecraft. Both satellites will be lifted into orbit by the Falcon Heavy, a new heavy-lift rocket built by private spaceflight company SpaceX.

SpaceX Falcon Heavy rocket — Launch
2017

Prox-1 and LightSail spacecraft — Deployment
2017

LightSail 2 and Prox-1 will be released into an orbit with an altitude of 720 kilometers (450 miles), high enough to escape most of the planet's atmospheric drag. Prox-1 will eject LightSail 2 into open space. Later, it will rendezvous with LightSail 2 and inspect it. When LightSail 2 unfurls its solar sails, Prox-1 will be nearby to capture images of the big moment.

LightSail’s primary contractor is Ecliptic Enterprises Corporation. The spacecraft has ground stations at Cal Poly San Luis Obispo and Georgia Tech. Cal Poly provides additional testing and integration support, and the project is managed by Dr. David Spencer of Georgia Tech. Boreal Space and Aquila Space serve as contractors to Ecliptic. LightSail was built by Stellar Exploration, Inc.

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Join Us In The Mission

LightSail needs your support! Our LightSail 1 test mission was successfully completed and our Kickstarter campaign ended June 26th, raising $1.24 million dollars for LightSail's 2017 solar sailing mission!

Miss the Kickstarter campaign, but still want to donate? You can! By donating to our project, you’ll be supporting The Planetary Society’s mission to engage and empower the world’s citizens to advance space science and exploration.

Support LightSail

You can also help by spreading the word about this exciting mission! Encourage friends, family, and colleagues to join us in the adventure of space exploration and share this website on your favorite social media platform.

Bill Nye