NASA is testing for the first time the effectiveness of a flexible solar array on space station that could one day power satellites and spacecraft. The Roll-Out Solar Array, or ROSA, an advanced, flexible solar array that rolls out like a tape measure “can be easily adapted to different sizes, including very large arrays, to provide power for a variety of future spacecraft. It also has the potential to make solar arrays more compact and lighter weight for satellite radio and television, weather forecasting, GPS and other services used on the Earth. In addition, the technology conceivably could be adapted to provide solar power in remote locations. NASA tested the ROSA technology in vacuum chambers on the Earth several years ago, but this is its first test in space. Over the weekend of June 17-18, 2017, engineers on the ground remotely operated the International Space Station’s robotic Canadarm2 to extract the Roll Out Solar Array (ROSA) experiment from the SpaceX Dragon resupply ship. The experiment will remain attached to the Canadarm2 over seven days to test the effectiveness of ROSA. Traditional solar panels used to power satellites can be bulky with heavy panels folded together using mechanical hinges. The new solar array design rolls up to form a compact cylinder for launch with significantly less mass and volume, potentially offering substantial cost savings as well as an increase in power for satellites. Smaller and lighter than traditional solar panels, ROSA consists of a centre wing made of a flexible material containing photovoltaic cells to convert light into electricity. On either side of the wing is a narrow arm that extends the length of the wing to provide support, called a high strain composite boom. The booms are like split tubes made of a stiff composite material, flattened and rolled up lengthwise for launch. The array rolls or snaps open without a motor, using stored energy from the structure of the booms that is released as each boom transitions from a coil shape to a straight support arm.The technology of the booms has additional potential applications, such as for communications and radar antennas and other instruments. The ROSA investigation looks at how well this new type of solar panels deploys in the microgravity and extreme temperatures of space.