Jason Davis • August 23, 2019
The Planetary Society’s LightSail 2 spacecraft is celebrating 1 month of solar sailing in Earth orbit. Since deploying its aluminized Mylar sail on 23 July 2019, the spacecraft has spent the majority of its time turning towards the Sun each orbit to get a slight push from solar photons. This has raised LightSail 2’s apogee, or orbital high point around the Earth, by 7.2 kilometers—all without a drop of conventional fuel.
The below chart tracks LightSail 2’s apogee and perigee since 12 July 2019, and highlights the increase in apogee that began shortly after sail deployment on 23 July. We will continue updating this chart daily; it’s also displayed on our Mission Control page.
This chart shows LightSail 2’s orbit apogee and perigee since 12 July 2019. Sail deployment occurred on 23 July 2019. The entire dataset can be downloaded here.
The Planetary Society / Data courtesy of NXTRAC
Last week we published a guide to spotting LightSail 2 in the night sky. Several people from the United States and 1 person from Syria wrote in to say they’ve seen the spacecraft. We also received the first image of LightSail 2 from a ground-based camera! The honor goes to Fabrizio Pinto from Izmir, Turkey.
Pinto previously worked at NASA’s Jet Propulsion Laboratory, and now teaches aerospace engineering at the Izmir University of Economics. He writes:
At JPL I did research on, among other things, navigation and flight mechanics of low thrust spacecraft (ion engines) on interplanetary missions, such as Deep Space 1. Therefore I have a natural interest in orbits that evolve under the action of small forces, including solar sails. I also studied solar sails as part of the science definition team of the Interstellar Probe—hopefully your activities will get us there some day!
LightSail 2 has now been communicating with Earth more than twice as long as the LightSail 1 mission lasted from start to finish (25 days). Pre-launch orbital models predict LightSail 2 will remain in orbit roughly a year.