Science

LightSail loses contact with Earth for 2nd time since launch

A solar sailing spacecraft has lost touch with Earth for the second time, shortly after it deployed its solar panels.

Spacecraft deployed solar panels before losing communication, but renewed contact expected

The bread-loaf-sized LightSail spacecraft was launched into orbit on May 20. It has lost contact with Earth for the second time since its launch, but the mission manager expects it will regain communication with Earth. (Planetary Society)

A solar sailing spacecraft has lost touch with Earth for the second time, shortly after deploying its solar panels.

LightSail fell silent "less than a day after completing what appeared to be a successful solar panel deployment," reported Jason Davis, digital editor for the Planetary Society, in a blog post earlier this week.

The Planetary Society is a space advocacy organization co-founded by the late astronomer Carl Sagan. It is headed by CEO Bill Nye, best known as the star of the television show Bill Nye, the Science Guy.

"The solar panels deploying was like an ice skater doing an arm extension while spinning," tweeted Barbara Plante, president of Boreal Space, on Thursday. Boreal Space is working with the Planetary Society on the LightSail mission.

Scientists believe a battery glitch caused the spacecraft to lose contact.

"Before contact was lost, LightSail's batteries did not appear to be drawing current from the solar arrays; nor were they properly shunting power to the spacecraft's subsystems," Davis said.

Solar sails are designed to capture the momentum from solar energy photons using large, mirrored surfaces. (YouTube/Planetary Society)
It's believed the spacecraft's batteries have entered a type of safe-mode condition that would protect the spacecraft's electronics until it regains power.

After LightSail re-establishes contact and its batteries recharge, Davis said, its solar sails will be unfurled.

Mission manager David Spencer expects to regain contact with LightSail, Davis tweeted.

LightSail last made contact at 4:40 p.m. ET on Wednesday. It then spent 10½ hours out of range, but stayed silent at its expected contact time on Thursday.

2nd time spacecraft loses contact

The spacecraft previously lost contact with Earth on May 22, due to a software bug that caused the flight system to crash once it collected more than 32 MB of data. LightSail got back in touch with ground stations on Earth after eight days of silence.

LightSail is a test designed to gather data for next year's flight in a higher orbit. The Planetary Society has a crowdfunding campaign to raise money for that mission.

The campaign originally sought to reach $200,000 US, but has already managed to raise more than $800,000. Now, Nye has announced a new goal of $1 million. The extra money from what the crowdfunding campaign calls a "big, hairy, audacious (but achievable!) goal" will help fund public education about the project.