Roll-Out Solar Array (ROSA) - 05.25.16

Overview | Description | Applications | Operations | Results | Publications | Imagery

ISS Science for Everyone

Science Objectives for Everyone
Solar panels are an efficient way to power satellites, but they are delicate and large, and must be unfolded when a satellite arrives in orbit. The Roll-Out Solar Array (ROSA) is a new type of solar panel that rolls open in space like a party favor and is more compact than current rigid panel designs. The ROSA investigation tests deployment and retraction, shape changes when the Earth blocks the sun, and other physical challenges to determine the array’s strength and durability.
Science Results for Everyone
Information Pending

The following content was provided by Jeremy A. Banik, Ph.D., and is maintained in a database by the ISS Program Science Office.
Experiment Details


Principal Investigator(s)
Jeremy A. Banik, Ph.D., Air Force Research Laboratory, Kirkland AFB, NM, United States

Allan Paskin, Deployable Space Systems, Inc., Santa Barbara, CA, United States

Air Force Research Laboratory (Hanscom Air Force Base), MA, United States
Deployable Space Systems, Inc., Goleta, CA, United States

Sponsoring Space Agency
National Aeronautics and Space Administration (NASA)

Sponsoring Organization
Technology Demonstration Office (TDO)

Research Benefits
Space Exploration

ISS Expedition Duration 1
March 2016 - September 2017

Expeditions Assigned

Previous Missions

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Experiment Description

Research Overview

  • The Roll-Out Solar Array (ROSA) is an innovative new solar array design that uses high strain one-piece composite slit-tube booms. The stored strain energy of the booms enforces the deployment actuation, and the booms provide the array's deployed structural stiffness and strength.
  • The flight experiment is designed to characterize the performance of the array in a relevant combined space environment to compare to scalable model predictions and on-ground test data. The intent is to compare this on-orbit ROSA data to the model predictions that have been previously validated by on-ground measurements in a simulated environment.
  • On-orbit data are used to fully develop the structural models for unique spacecraft applications and higher power levels. As such, the flight experiment is designed in a combined space thermal, vacuum, and micro-gravity environment in order to:
    • Characterize deployment loads and kinematics
    • Characterize the deployed structural dynamics
    • Characterize the structural dynamics  that occur going from eclipse to illumination
    • Characterize blanket structural survivability and photovoltaic performance after launch and deployment
    • Characterize retraction loads and kinematics.
  • ROSA significantly improves the power density and stowage efficiency and scalability over current rigid panel array technology and shows high promise for consideration on all future NASA, Department of Defense (DoD) and commercial spacecraft.


The research plan is broken into four main objectives with experiments designed around satisfying each of the stated objectives. Objectives include characterizing the Roll-Out Solar Array (ROSA) structure deployment loads and kinematics, the deployment torque, the deployment kinematics, and the velocities and accelerations of the array during deployment and blanket tensioning. The ROSA deployed structural dynamics and the changes in full-sun and full-shadow are measured, as well as the fundamental frequency and mode shape for the system bending mode and the blanket drum mode.
Many operational parameters such as structural damping, structural dynamics during eclipse exit, blanket structural survivability and photovoltaic performance post launch and post deployment, I-V curve immediately following deployment and dynamics experiment, I-V curve each time array is at optimal solar illumination throughout mission life, structure retraction loads and kinematics, retraction torque, retraction kinematics, velocities and accelerations of the retracting array and blanket tension release.

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Space Applications
ROSA has the potential to replace solar arrays on future satellites, making them more compact and lighter weight. Satellite radio and television, weather forecasting, GPS and other services used on Earth would all benefit from high-performance solar arrays.

Earth Applications
The International Space Station, telecommunications and research satellites, and satellites for military use are all powered by solar arrays, which convert sunlight into energy. ROSA is a new design that uses a one-piece, flexible composite material that snaps open in space. It has higher power density than existing technology and can be easily adapted to different sizes, making it a promising material for use on all future NASA, military and commercial solar-powered spacecraft.

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Operational Requirements and Protocols
ROSA is stowed in the trunk of the SpaceX’s Dragon capsule during launch. Once on orbit, the ISS robotic arm removes ROSA from the Dragon trunk and temporarily stows it on an ELC. When ROSA operations are ready to begin, the ROSA is picked up by the ISS robotics arm and located in its operations location. The ROSA operations are conducted while attached to the SSRMS/SPDM for a duration of 7 days. During initial deployment of the array, video is required. Data are recorded using embedded sensors on the experiment. Testing is activated and commanded via the ground controllers (ROBO). Payload Health and Status and Experiment Data are downlinked via 1553 communications.

Deployment is monitored by cameras, limit switches, eddy current damper voltage, and accelerometers placed on the tip of the mandrel and the blanket. Visual markers are placed on the booms, blanket, and tip mandrel to provide a visual index of array deployed length. These same markers are used during the dynamics testing to infer the fundamental frequency and associated mode shape through post-processing. A sinusoidal actuation at the array root with a motor will sweep across a frequency range at various rates. The dynamic response is measured via accelerometers on the mandrel and ROSA dynamics response is further characterized during thermally induced impulse loading due to eclipse exit.
The blanket and photovoltaic performance are measured by collecting current-voltage (I-V) sweeps from near the open circuit voltage to near the short circuit current. Sweeps are performed approximately every two minutes for the duration of the mission. Temperature, sun angle and shadowing are measured in order to correlate the measured I-V data.

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Decadal Survey Recommendations

Information Pending

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Results/More Information

Information Pending

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Related Websites

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