A tiny spacecraft is about to sail into its demise, burning up as it reenters Earth’s atmosphere for the end of its mission.
The Planetary Society’s LightSail 2 has been getting dragged down by the pull of Earth’s atmosphere, and is expected to reenter the atmosphere within the next few days, the organization announced on Monday. When it does, the spacecraft will burn up, bringing its three and a half year journey of orbiting Earth to a fiery end.
“We always knew this would be the eventual fate for the spacecraft,” The Planetary Society wrote. “Despite the sadness at seeing it go, all those who worked on this project and the 50,000 individual donors who completely funded the LightSail program should reflect on this as a moment of pride.”
LightSail 2 launched in June 2019, unfurling its 344-square-foot (32-square-meter) solar sail a month after reaching its orbital post. The purpose of the mission was to test solar sailing as a way for spacecraft to travel.
Solar sails run on photons from the Sun, causing small bursts of momentum that propel the spacecraft. As the photons hit LightSail’s wings, the spacecraft was pushed further away from the Sun, reaching higher altitudes. Just two weeks after spreading its wings, LightSail 2 gained 2 miles (3.2 kilometers) of altitude, making this experiment a success.
The mission has even far exceeded its initial one year timeline, and has been orbiting Earth for 3.5 years, completing 18,000 orbits, and covering 5 million miles (8 million kilometers). But for the past few months, LightSail 2 started losing altitude at an increasing rate.
The spacecraft has been the victim of atmospheric drag, causing LightSail 2 to slow down as it smashed into atmospheric particles during its orbit. The Sun also played a part in LightSail 2's demise, heating up Earth’s upper atmosphere, and causing it to become denser, which slowed down the spacecraft.
The mission also suffered from communication glitches due to faulty equipment at the ground station. During times of communication drop-off, the team was unable to send data to the spacecraft, causing its sailing to slightly suffer.
After sinking lower through Earth’s atmosphere, the spacecraft will eventually reenter the atmosphere. During reentry, LightSail 2 will be moving so quickly that it will create an energetic pressure wave ahead of it, causing the air around it to heat up and turn the spacecraft into a disintegrating ball of fire.
LightSail 2 may be coming to an end, but the experiment has already inspired a new generation of spacecraft. Those spacecraft include NASA’s NEA Scout mission to a near-Earth asteroid (scheduled for launch in August), NASA’s Advanced Composite Solar Sail System to test out sail boom material in Earth orbit (scheduled for launch sometime mid-2022), and NASA’s Solar Cruiser (scheduled for a 2025 launch).
We’ll be looking out for LightSail’s fiery reentry, bidding farewell to the long-running solar sailor.