The Planetary Society’s crowd-funded LightSail-A solar sail test mission nearly came to a premature end twice before it even had a chance to unravel itself. Two days after its launch on 20 May on an Atlas V, along with the X-37B OTV Mission 4 space plane and several cubesats, the 3U-cubesat LightSail-A craft with is solar arrays folded out, developed trouble when its computer shut down and telemetry contact was lost. The cause was due to cosmic radiation triggering a reboot of the system.
Having been recovered, there was further trouble on 4 June when a battery charging anomaly resulted in their not being enough power to initiate the unfurling of the solar sail (the spacecraft was apparently intermittently receiving too little or to much power from its solar cells). Eventually, however, the spacecraft had enough battery power and the 5.5m square solar sail was fully unfurled. LightSail-A re-entered the Earth’s atmosphere on 14 June 2015. With the concept being proven, further solar sails are being planned for interplanetary missions, similar to the Ikaros mission to Venus conducted by the Japanese space agency JAXA.
