A solar-navigation mission now marks three years of spaceflight, but is unlikely to celebrate a fourth anniversary.
The Planetary Society’s LightSail 2 is a crowdfunded solar sail that was launched on June 25, 2019. It was expected to last a year in a spacecraft performance evaluation using only the power of the sun.
Now tripling that expectation, the spacecraft continues to perform well but battles atmospheric drag. Molecules from Earth’s atmosphere are slowly dragging the spacecraft back to our planet, with reentry expected in perhaps a few months, according to an update from the Planetary Society (opens in a new tab).
“We have continued to work to learn more and navigate more efficiently through its extended mission including its second year in orbit as well as this final year, its third year,” wrote Bruce Betts, the mission’s project manager. , Friday, June 24. ) on the Planetary Society website.
Related: LightSail 2 captures stunning photos of Earth from space
Like any long-duration mission, the spacecraft encountered a few challenges. Last summer, engineers recalibrated the spacecraft’s gyroscopes to account for drift, but the gyroscopes “began returning data that measured incorrect spin rates,” Betts wrote.
“We developed techniques to calibrate the gyroscopes in orbit and updated the onboard flight software to allow corrections to the gyroscope bias parameters. The update improved our sail control, improving our solar navigation. “
The change allowed the altitude to increase by 328 feet (100 meters) per day for a few months, but to date the average altitude is around 390 miles (627 kilometers). This is to be compared with 446 miles (718 km) at the start of the mission.
The altitude dropped for several reasons, Betts explained, including problems communicating with the spacecraft due to ground station components breaking (and requiring replacement), continued atmospheric drag, and l increased activity in the 11-year solar cycle swelling Earth’s atmosphere and moving more higher molecules.
That said, the Mylar sail material remains in good condition and the spacecraft has no major component failures, which Betts says is “incredible testimony to the dozens of people who have worked on it over the years. “.
He added that the team plans to “make the most of the next few months” before LightSail 2’s eventual reentry, but the data collected will remain useful essentially forever after the mission. The team plans many mission analyses, paper publications, and conference publications for LightSail, as well as continuing their connections with other space missions planning to use solar sails themselves.
In the meantime, the LightSail team continues to release updates via technical publications (opens in a new tab) and, while the mission is active, you can view key parameters via the Mission Control Dashboard (opens in a new tab).