LightSail 2, designed and crowd-funded by the Planetary Society - at a cost of just $7m - is a very small spacecraft that's been sailing at high-speeds in Earth’s orbit since 2019.
Travelling 430 miles above us, it takes around 100 minutes for LightSail 2 to orbit the Earth and for 28 minutes of each orbit it can turn its 34 square metre sail (that's roughly the size of a boxing ring), which rather than absorbing the light like normal cloth, repels it thanks to its reflective material called Mylar. This enables it to steer and reposition itself without the need for any chemical propulsion.
LightSail 2 data is directly supporting NASA’s solar sailing programmes which the agency describes as being capable of “conducting orbital plane changes more efficiently than spacecraft using conventional chemical propulsion,” and “of achieving remarkable speeds, enabling rapid exploration of the outer solar system.”
During the past year, the LightSail 2 mission team has continued to optimize the spacecraft’s performance and report their results to the space science community. It's primary mission is to demonstrate that solar sailing is a viable means of propulsion for CubeSats - small, standardized spacecraft that are part of a global effort to lower the cost of space exploration.The Planetary Society will now operate LightSail 2 under an extended mission phase, making various operational refinements and studying how the spacecraft’s orbit evolves in response.
Future missions will take place at higher orbits, or even on interplanetary trajectories. NASA’s version of the same concept, NEA Scout ,will ride a Space Launch System rocket to an area near the Moon before deploying its solar sail to ride cosmic winds on a visit to an asteroid.
It’s a tremendous achievement for the Planetary Society, who created the entire venture, from blueprints to the extended mission phase. The work stretches over a decade, on just $7 million, gathered from Planetary Society memberships, private donations, foundational support, corporate partners, and a 2015 Kickstarter campaign which holds the record for the most successful space-related Kickstarter in history: raising $1.24 million courtesy of 23,500 backers.
“Even a year later, I am inspired and humbled by the tens of thousands of passionate individuals who came together to make this mission a reality,” said Planetary Society chief operating officer Jennifer Vaughn. “As we celebrate the success of LightSail 2’s primary mission, we’re also celebrating the power of everyday people working together to explore space.”