Text Size
Advanced Solar Array Systems
October 31, 2012

›  Link to larger photo

ROSA ROSA "Winglet"
›  Link to larger photo

MegaFlex Solar Array on SEP Vehicle MegaFlex Solar Array on SEP Vehicle
›  Link to larger photo

Stowed UltraFlex and MegaFlex Stowed UltraFlex and MegaFlex
›  Link to larger photo
NASA's Space Technology Program selected ATK Space Systems, Inc. and Deployable Space Systems (DSS), both of Goleta, Ca., to develop solar array systems that will enable electric propulsion systems of the future.

The companies will have 18 months to develop their SAS technologies under Phase I of this solicitation. It is expected that either one or both will be selected for a Phase II award to demonstrate their technologies in space.

The Phase I awards range between approximately $5 million and $7 million each.

Deployable Space Systems

The ROSA technology (Roll-Out Solar Array) is a new/innovative mission-enabling solar array system that will offer maximum performance in key areas and affordability for NASA's future space missions. The Mega-ROSA architecture integrates multiple high-voltage elastically deployable ROSA modular "winglet" elements into a deployable backbone structure. It features a flex-blanket solar array configuration conducive to providing high power levels.

The technology is proposed to be lighter and less expensive then current solar array designs, offer compact stowed packaging and strength and stiffness that is conducive to providing power levels – from 60kW to more than 300kW and increase the solar array's deployed stiffness and strength, operation reliability, radiation tolerance, scalability, and high voltage operation capability.

During Phase I development, Deployable Space Systems will build two 15-20kW ROSA winglets approximately 4.5 meters wide and 14 meters long. The ROSA platform includes the deployable PV flex-blanket module or "winglet." Attached to the composite boom structure will be a lightweight Integrated Modular Blanket Assembly (or IMBA) photovoltaic assembly.

Prototype ROSA hardware built by Deployable Space Systems underwent more than 100 successful functional deployments, at ambient, hot, and cold temperatures and >3:1 positive torque margins validated.


Development of MegaFlex technology will leverage the mission-proven Ultraflex solar array design will be scaled up for power levels between 30-50kW in Phase 1.

MegaFlex - like Ultraflex, which was used on the Mars Phoenix Lander - is an accordion fanfold flexible blanket solar array comprised of interconnected isosceles-triangular shaped lightweight substrates, or gores. Photovoltaic cells are bonded to the weave mesh blankets. When stowed, the solar array is configured as a flat-pack to produce a compact launch volume and high system frequency. The circular membrane structure, which contains radial spar elements, becomes tensioned similar to an umbrella, resulting in a highly efficient, strong and stiff structure.

The technology proposes to achieve power levels of 250kW or higher and greatly improve mass and packaging efficiency of current solar arrays.

The key advancement from Ultraflex to Megaflex arrays - which will be demonstrated by ATK during Phase 1 - is the way the folded arrays are stowed (folded) during launch. The spar/panel pivot will reduce the stowed length, which is required during the unfolding to achieve the required panel radius. This would allow two scaled-up 200 kW Megaflex wings (resulting in a total power of 400 kW) to be compatible with potential mission platforms and currently available launch vehicles.

Image Token: 
Image Token: 
Page Last Updated: July 28th, 2013
Page Editor: NASA Administrator