Sail Away

In the modern era of space exploration, it’s not just government agencies getting in on the action. While companies like SpaceX and Boeing often get press for building the large rockets of today and tomorrow, it’s also important for other organizations to learn how to maneuver a spacecraft once it’s in orbit.

The spacecraft turns, catching sunlight when it wants a boost, and turning edge on to the sun when it doesn’t.

Josh Spradling/The Planetary Society

Most vehicles carry propellant to adjust their trajectories when needed. But over time, many of their orbits will degrade, bringing them to the outer edges of Earth’s atmosphere. Here, the drag of air particles, if left uncorrected, will siphon off energy, pulling the craft closer to Earth. Other times, minor corrections are needed to avoid close encounters with other spacecraft. And of course, many spacecraft are first deposited into a convenient orbit by a rocket before they maneuver into their final, preferred orbital path.

But propellant is a consumable resource, so eventually all spacecraft will run out of fuel — that is, unless they can use a renewable resource, such as sunlight, to power their movements. By using Earth’s magnetic field to orient itself and angle its sails toward our star, LightSail 2 can control its own movements.

Of course, such a sail can provide only so much force. But LightSail was designed for CubeSats, which are tiny satellites weighing no more than three pounds that you can hold in your hand.

LightSail 2 is still a proof-of-concept spacecraft. The cameras and equipment on board are all focused on making sure controllers on Earth know that it has done its job successfully. It has laser ranging equipment so lasers from Earth can ping the spacecraft and verify its distance, as well as sensors and cameras so engineers know that the craft is operating as expected.

So far, the LightSail 2 has expanded its orbit more than a mile since it deployed its sail, much to the delight of mission managers.

In a pre-launch briefing on June 20, Jennifer Vaughn, COO of the Planetary Society, discussed the next steps for solar sail technology, which may take place without the Planetary Society.

“There’s no plan for LightSail 3. But that’s because we’re not a LightSail company. … LightSail 3 is for other people to take on, not necessarily with that name, but what we try to do is we try to get a technology ready to then hand off to the world and then it be implemented by others.”