HELIOS is an advanced solar sail concept being evaluated by NASA's Space Technology Mission Directorate (STMD).

NASA's STMD rapidly develops, demonstrates, and infuses revolutionary, highpayoff technologies through transparent, collaborative partnerships, expanding the boundaries of the aerospace enterprise.

http://www.nasa.gov/spacetech
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From the video:

NASA is designing a nextgeneration solar sail: HELIOS, or HighPerformance Enabling LowCost Innovative Operational Heliogyro Solarsail.

HELIOS will demonstrate a type of high performance solar sail called a heliogyro. The "sail" of the heliogyro consists of very long reflective membrane strips, or blades.

Blades are rolled onto reels to simplify packaging and deployment. Sunlight reflecting on the blades creates thrust. No onboard fuel is required.

HELIOS requires no additional structure to maintain its shape. This reduces weight and permits higher accelerations and shorter travel times to distant destinations.

HELIOS also steers like a helicopter. Tilting each blade redirects the reflected sunlight and solar pressure. This can be used to change thrust, orientation relative to the Sun or spin rate.

Cameras will capture the motion of the blades, sending proof of deployment to Earth, recording video to compare with computer models and communicating blade motion to the blade control system.

Future HELIOS solar sail missions:
Solar weather early warning
Imaging the poles of the Sun
Travel beyond the Solar System