Less than a year after the LightSail cubesat successfully deployed its solar sails in space, the Planetary Society has unveiled its successor, an experimental spacecraft designated LightSail-2. LightSail-2 is still under development, but if all goes well this prototype solar sail spacecraft will be on board SpaceX's Falcon Heavy rocket during its first operational flight scheduled for later this year. Eight months ago, its smaller predecessor, LightSail-1 (formerly known as LightSail-A), unfurled its sail after mission controllers overcame some technical problems. Unlike LightSail-1, the new solar sail spacecraft will be placed in a high-enough orbit to allow for actual sailing.
Credit: The Planetary Society
Planetary Society CEO Bill Nye is a major proponent of the technology, touting its potential as an efficient, low-budget option to space exploration. As conceived by Carl Sagan decades ago, the lightsail's propulsion is provided by solar radiation; solar photons exert radiation pressures on the sail, which produces a small degree of acceleration. It will start off slow, but the continuous stream of sunlight, plus the complete absence of friction, should allow it to reach relatively high speeds over time.
The new light sail features four triangular sails, made of mylar, which combine to form a rectangular-shaped surface. Once the 3U cubesat reaches an orbital altitude of 800km, the sails will deploy, extending across a total area measuring 32 square metres. The main test goal will be to assess whether the solar sails are a viable form of spacecraft propulsion.
In celebration of the name change, the Planetary Society released a new video showing a sail deployment test at Ecliptic Enterprises Corporation in Pasadena.
Writing in The Planetary Society, Jason Davis explains what happened during the test:
Unsurprisingly, [the] deployment tests revealed minor issues that engineers...have spent the past few weeks working to resolve. The deployment motor hesitated several times, not unlike the way it did during LightSail 1 testing. There was a glitch with the spacecraft's onboard cameras, which capture staggered images during the sail deployment sequence. And additional refinements are still being applied to the spacecraft's communications and attitude control systems.
A second round of system testing is planned at Cal Poly. This will pave the way for a full, day-in-the-life test as soon as March, when the spacecraft demonstrates its core mission functions one final time on the ground.
For the launch, LightSail-2 will be coupled with the Prox-1, a satellite designed to test formation flying, which is currently being built at Georgia Tech.
No firm date has been set for launch, as it's dependent on when Falcon Heavy rocket will be ready.