Space

LightSail 2 mission reaches fiery end after 3-year solar sailing demo

The final image sent back by LightSail 2, before the mission came to an end as the spacecraft burned up on reentry into Earth's atmosphere
The Planetary Society (CC BY-NC 3.0)
The final image sent back by LightSail 2, before the mission came to an end as the spacecraft burned up on reentry into Earth's atmosphere
The Planetary Society (CC BY-NC 3.0)

After more than three years circling the Earth, the Planetary Society’s LightSail 2 mission has come to an end following a fiery reentry. The satellite was an important tech demo for the idea of solar sailing, which could eventually propel spacecraft to other stars.

LightSail 2 was launched aboard a SpaceX Falcon Heavy rocket in June 2019, settling into an initial orbit at an altitude of around 720 km (450 miles). At that height, the Earth’s atmosphere is still thick enough to create drag, which would threaten to eventually pull the spacecraft down.

But that’s where the plucky little satellite’s special ability came in. Although it’s only the size of a shoebox, LightSail 2 unfurled a big reflective sheet, called a solar sail, about the size of a boxing ring. The idea is that photons from sunlight strike this sail and generate tiny amounts of thrust, allowing the craft to change its orbit.

And LightSail 2 demonstrated this concept beautifully. In three and a half years, the spacecraft completed around 18,000 orbits and traveled 8 million km (5 million miles), adjusting its orbit continuously to keep itself aloft. But all good things must come to an end, and sometime on November 17, drag finally won the tug-of-war and pulled the spacecraft back to Earth.

“During its extended mission LightSail 2 continued to teach us more about solar sailing and achieved its most effective solar sailing, but that was followed by an increase in atmospheric drag in part from increasing solar activity,” said Bruce Betts, LightSail program manager. “The spacecraft is gone, but data analyses and sharing of results will continue.”

The data from LightSail 2 will inform future solar sailing missions, including the Near Earth Asteroid (NEA) Scout, which coincidentally launched on LightSail 2’s last day in operation. Shot into space aboard NASA’s Artemis I mission to the Moon on November 16, NEA Scout will rendezvous with asteroid 2020 GE and snap close-up images of it. It’ll get there using a solar sail measuring 86 sq m (926 sq ft), more than 2.5 times larger than that of LightSail 2.

Longer term, it’s thought that light sails coupled with powerful lasers could help us reach other star systems in as little as 20 years.

Source: The Planetary Society

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5 comments
michael_dowling
I am presently reading the new Avi Loeb book 𝐄𝐱𝐭𝐫𝐚𝐭𝐞𝐫𝐫𝐞𝐬𝐭𝐫𝐢𝐚𝐥,and am at the part where he is talking about the Breakthrough Starshot project that will send a bunch of tiny light sails equipped with cameras to the Alpha Centauri star system for a look-see. Power to get them up to relativistic speeds would come from very powerful earthbound lasers.
Kent Dogey
¡ Starboard !
FB36
IMHO, such a project like Breakthrough Starshot is actually possible but the current approach is absolutely wrong/impractical!
The right/practical approach would be first designing/creating arrays/panels of massive numbers of tiny/efficient (solid-state) lasers or (white) LEDs & having/carrying them onboard the probe!
(& use a Radioisotope Thermoelectric Generator (RTG) as the power source!)
Yes, the thrust produced would be tiny but it would be continuous (just like wanted/required)!
& the whole project would be far less costly/risky!
ljaques
Forget that slo-mo method. Instead, invent artificial gravity coupled with inertial dampeners. Elon, are you listening? ;)
TpPa
ljaques: I think good old Elon is so overload that he is just going to walk away from it all, and follow Tony Starks example, work at home, and come up with a bunch of new and exciting things, seeing he will be in a relaxed atmosphere, and his brain will work again like when he first came into play.