LunarSail - the crowdfunded mission to the Moon

The LunarSail Project raised almost $16,000 from 260 Kickstarter backers to build a sail-propelled spacecraft to the Moon. Off-duty engineers and space enthusiasts living near Nasa’s Kennedy Space Center volunteer their time to the non-profit Ares Institute, which promotes space to encourage science and math education.

A constant stream of photons and particles - the solar wind - stream from the Sun every second. This creates a weak, but constant, force on everything it strikes. The solar wind creates the tails of a comet as it carries away the dust and gas boiling off the comet’s core. A solar sail takes advantage of this pressure to propel spacecraft without rockets or propellant - the Sun itself is the fuel tank. The weak force of the solar wind striking the sail pushes the spacecraft away from the Sun. Compared to the crushing forces of a rocket launch, the push on a spacecraft’s solar sails are almost nothing. But given enough time almost nothing adds up. Rockets can only burn for a few seconds or minutes. Solar sails work all the time and can take you anywhere in the Solar System and beyond. The only catch is you need a very large sail and a very light spacecraft.

LunarSail is a CubeSat with a 400 square meter membrane sail. It’s based on a proven design - the NanoSail-D that Nasa sent into orbit in 2010. After the sail unfurls in low-Earth orbit the Sun’s light will push the spacecraft towards the Moon slowly. Very slowly. China’s Chang’e lunar lander only took five days. LunarSail’s journey from Earth to the Moon will take almost three years. The looping trajectory will spiral away from Earth until it’s cast into deep space and begins spiraling in towards the Moon. Along the way the spacecraft will measure the space environment - radiation, solar wind, and micrometeoroids - in this largely unexplored region. 

The crowdfunders at Kickstarter blew away the project’s $10,000 goal. Thanks to the $16,000 in crowdfunding, the Ares Institute bought the spacecraft’s hardware and began the development phase. But public participation doesn’t end there. Ham radio operators will receive the signals LunarSail broadcasts from the Moon. The project's Kickstarter backers will use LunarSail’s cameras to take pictures of the Moon’s surface. It may take time, but LunarSail will let amateurs explore the Moon.