A citizen-funded spacecraft that will be in Earth's orbit fuelled by the sun's energy is gearing up to deploy its sails later this month after being launched into outer space in June.
Packed inside the LightSail 2 are sails that will capture light energy from the sun in order for the craft to orbit Earth, according to the Planetary Society, the independent space-interest organisation responsible for the project.
It also houses a small satellite called a CubeSat, which is about the size of a loaf of bread.
LightSail 2 was supposed to deploy its sail on Monday but now expects to do so no earlier than July 21 after the satellite's "attitude control system" — or ability to control its orientation in relation to other objects — has been further tested, the organisation announced.
Tuesday's announcement came after the "flight controllers saw unexpected results" during testing of the system. In a Planetary Society mission update posted online, the spacecraft mission manager Dave Spencer said they wanted to take some time pressure off the team to ensure that they can address the problems.
The spacecraft is meant to test solar sailing technology by deploying its 32-square-metre solar sail and using sunlight to change its orbit.
"This is space flight by sunlight," Planetary Society CEO Bill Nye said in a LightSail 2 video presentation in May.
Solar-powered flight is expected to reach higher speeds than chemical-fuelled satellites over time through continuous acceleration, the Planetary Society said on its website.
"As light reflects off a sail, it transfers momentum to the sail and pushes it," the large non-profit space organisation said.
Last weekend, the LightSail 2 first sent back pictures of the Earth.
The spacecraft first contacted "home" last week after leaving its carrier vehicle. The small craft was launched into space on a SpaceX Falcon Heavy launch vehicle on June 25.
It's the second version of solar spacecraft that the independent Planetary Society has launched — LightSail 1 was a 2015 test mission.
The final bill for the project is expected to be around $5.45 million (€4.86 million) of which $1.24 (€1.1 million) was raised via Kickstarter.
This article has been updated to reflect new developments that the spacecraft will delay deployment of sails.