The solar sail mission now commemorates three years of spaceflight, but is unlikely to celebrate its fourth anniversary.
The Planetary Society LightSail 2 is a publicly funded solar sail that launched on June 25, 2019. It was expected to last a year to evaluate how well the spacecraft would perform using the power of the Sun.
After tripling this prediction, the spacecraft continues to function well but struggles with atmospheric resistance. Earth’s atmosphere particles are slowly dragging the spacecraft back to our planet, with re-entry expected within a few months, according to the Planetary Society Update. (Opens in a new tab).
“We have continued to work to learn more and navigate more efficiently as part of its extended mission including its second year in orbit as well as last year, its third,” Bruce Bates, the mission’s project manager, wrote on Friday (24 June). ) on the Planetary Society website.
Related: LightSail 2 takes stunning photos of Earth from space
Like any long-duration mission, the spacecraft has faced some challenges. Last summer, Bates wrote, engineers recalibrated the gyroscopes on the spacecraft to calculate drift, but the gyroscopes “began returning data that measured incorrect rotation rates.”
“We have developed techniques for in-orbit gyroscope calibration, and updated the onboard flight software to enable corrections for gyroscope bias parameters. The modernization has improved our sailing control, thus improving solar sailing.”
The change allowed the altitude to rise 328 feet (100 meters) per day for a few months, but as of today the average altitude is about 390 miles (627 kilometers). That’s compared to 446 miles (718 km) at the start of the mission.
Bates explained that the altitude decreased for several reasons, including a communications problem with the spacecraft due to broken ground station components (which required replacement), persistent atmospheric drag, and increased activity in 11 years. The solar cycle blows the Earth’s atmosphere and moves more particles upward.
However, the Mylar sail material is still in good condition, and the spacecraft has had no major malfunctions in its components, which Bates said is “an amazing testament to the many people over the years who have worked on it.”
He added that the team plans to “make the most of the next several months” before the final re-entry of LightSail 2, but that the data collected will essentially remain useful forever after the mission. The team plans numerous mission analyzes, paperbacks, and conference publications for LightSail, as well as their continued communications with other space missions that plan to use solar sails themselves.
In the meantime, the LightSail team continues to post updates through technical publications (Opens in a new tab) And while the task is active, you can view the main parameters through the task control panel file (Opens in a new tab).