Efficient and lightweight solar array technologies are critical for powering spacecraft and instruments during deep space missions, where sunlight is weaker and mission demands are higher. Developing advanced solar arrays enables longer, faster, and more capable interplanetary travel, supporting propulsion, life support, and scientific operations far from Earth.
Innovations in Solar Array Technologies
Roll-Out Solar Arrays (ROSA)
ROSA technology represents a major advancement in solar power for space missions. These arrays consist of flexible, rollable blankets that can be compactly stowed during launch and then deployed to large surface areas in space. ROSA offers higher power output with reduced mass and complexity compared to traditional rigid panels. Demonstrated aboard the International Space Station and slated for missions like NASA’s Double Asteroid Redirection Test (DART), ROSA provides continuous power to solar electric propulsion systems, enabling spacecraft to reach speeds exceeding 324,000 kilometers per hour-over five times faster than Voyager 1[2][5].
MegaFlex Solar Arrays
Developed by ATK under NASA contracts, MegaFlex arrays build on smaller UltraFlex designs to deliver very large, low-mass solar arrays with low stowage volume. MegaFlex arrays, measuring roughly 10 meters across when deployed, are designed to support high-power missions requiring hundreds of kilowatts, including deep space crewed vehicles like the Orion capsule[7].
Vertical Solar Arrays for Challenging Environments
For environments with low sun angles, such as the lunar south pole, vertical solar arrays (VSAT) have been developed to maximize sunlight capture. These arrays autonomously deploy and retract, adapting to terrain and mission needs, and have been rigorously tested for lunar gravity, temperature extremes, and regolith exposure[9].
Key Advantages for Deep Space Missions
– High Power-to-Mass Ratios: Advanced arrays like ROSA and MegaFlex reduce launch mass and volume while providing greater electrical power, critical for propulsion and onboard systems.
– Scalability and Modularity: Flexible designs allow arrays to be sized and configured to mission requirements, from small probes to large crewed spacecraft.
– Durability and Reliability: Materials and deployment mechanisms are engineered to withstand harsh space environments, including radiation, micrometeoroids, and thermal cycling.
– Enabling Advanced Propulsion: Coupled with solar electric propulsion, these arrays enable faster transit times and extended mission durations by supplying continuous, high-density power.
Challenges and Future Directions
– Reduced Solar Intensity: As missions venture beyond the inner solar system, solar irradiance diminishes, requiring more efficient photovoltaic materials and larger arrays.
– Deployment Mechanisms: Ensuring reliable, autonomous deployment in zero gravity and variable conditions remains a technical challenge.
– Integration with Spacecraft Systems: Arrays must be compatible with spacecraft power management, thermal control, and structural constraints.
– Material Innovation: Research into lightweight, radiation-hardened, and flexible photovoltaic materials continues to improve performance and longevity.
Summary
Advanced solar arrays such as Roll-Out Solar Arrays, MegaFlex, and vertical solar technologies are transforming power generation for deep space exploration. By delivering efficient, lightweight, and scalable power solutions, these innovations support faster interplanetary travel, extended mission durations, and enhanced scientific capabilities. Continued development and testing of these technologies are vital to overcoming the power challenges posed by deep space environments and achieving humanity’s goals of exploring and understanding the solar system and beyond.
Read More
[1] https://ntrs.nasa.gov/api/citations/20090007813/downloads/20090007813.pdf
[2] https://www.nasa.gov/directorates/stmd/impact-story-roll-out-solar-arrays/
[3] https://www.sciencedirect.com/science/article/abs/pii/B9780128233009000066
[4] https://www.usasymposium.com/deepspace/
[5] https://redwirespace.com/newsroom/redwires-innovative-solar-array-technology-powering-the-future-of-space-exploration/
[6] https://arxiv.org/html/1701.05205v5
[7] https://www.space.com/18195-atk-megaflex-solar-array.html
[8] https://scholarworks.uark.edu/etd/4712/
[9] https://www.lockheedmartin.com/en-us/news/features/2025/powering-the-moon–vertical-solar-arrays-charge-the-way-.html
[10] https://ulab.studentorg.berkeley.edu/static/doc/posters/s213.pdf