The nonprofit Planetary Society says its LightSail 2 experiment spread out its solar sails today, nearly a month after it took a piggyback ride to orbit aboard a SpaceX Falcon Heavy rocket.
Following through on 2015’s LightSail 1 mission, this latest flight is designed to demonstrate not only that the 18.4-foot-wide, 4.5-micron thick reflective Mylar sails can be successfully deployed from a shoebox-sized spacecraft, but also that they can be used to maneuver in orbit.
LightSail 2 is pushed by the pressure of sunlight, much as a seagoing sailboat is pushed by the pressure of the wind. Theoretically, bigger and more capable sails could be used to drive a spacecraft around the solar system, or even outward to other stars.
The $7 million project is largely funded by Planetary Society members and private donors. LightSail 2 was packed aboard the Falcon Heavy as part of a larger payload called Prox-1 and delivered to orbit on June 25. Since then, the spacecraft has been going through checkouts and snapping pictures of the planet below.
Today’s crucial unfurling of the experiment’s four triangular sails was monitored closely from Mission Control at Cal Poly in San Luis Obispo, Calif. Huddled around their laptops, team members broke out in applause when telemetry indicated that the deployment mechanism performed as expected.
“Success! We’re sailing, peoples!” the Planetary Society’s executive director, Bill Nye (the Science Guy), exulted in a tweet.
Success! We’re sailing, peoples! https://t.co/UnLbtS7CKg
— Bill Nye (@BillNye) July 23, 2019
Hours later, the Planetary Society reported that the spacecraft’s major systems “were reporting nominally.” Early signs suggested that the sail array was tracking the sun properly, but controllers said communications with the spacecraft weren’t as good as expected, perhaps due to the craft’s orientation as it passed overhead.
The Mission Control team wasn’t able to download the first post-deployment images but will try again on Wednesday.
LightSail 2 has already built up a gallery’s worth of images from its 450-mile-high orbit, including glorious views of Earth’s ocean-blue and cloud-white disk.
The Planetary Society offers a tracking website that provides LightSail 2’s current location and sighting opportunities. However, because the spacecraft is in a 24-degree orbital inclination, it won’t be visible at latitudes greater than 42 degrees north or south. For North America, that means locations north of Chicago and New York are out of luck.
The experiment’s orbit-raising phase is expected to last about a month. LightSail 2’s attitude control system isn’t sophisticated enough to keep its orbit circular as it maneuvers, and that means atmospheric drag will eventually force the spacecraft into a fiery final plunge. With luck, the sails could last a year before they burn.