Solar Energy Systems in Rockets

Batteries used in rocket electronic systems create a significant load both in terms of weight and volume. The energy required for the operation of the mission computer, telemetry, GPS, accelerometer, and other sensors is often provided by high-capacity batteries. However, one of the most important goals in rocket design is to eliminate every unnecessary gram. Therefore, an innovative idea that has emerged in recent years is attracting attention: minimizing battery needs by placing integrated solar panels on fin surfaces.
This approach is based on the principle of powering rocket electronics directly with energy produced during flight. Thus, both weight is reduced and energy continuity is ensured.

Why Does a Solar Panel on the Fin Make Sense?

Fins are one of the regions of the rocket that receive the best light throughout the flight. Their surfaces are parallel to the flow and shading by the rocket body is minimal. This also makes them ideal for micro solar panels.
Main advantages provided by this design:

  • 1. Eliminating Battery Weight

    LiPo or Li-ion batteries used in rockets are both heavy and take up volume. By using solar panels on fin surfaces:

    • Total payload area increases,
    • Weight balance becomes easier,
    • Electronic module design is simplified.

  • 2. Energy Continuity

    • Even in short-duration flights, sensors, telemetry, and recording units need continuous power. Solar panels especially provide uninterrupted energy:

    • During pre-flight ground waiting,
    • During launch pad preparation,
    • At the moment of climbing to the sky.

    In this way, risks such as sudden voltage drop of the battery, cold air effect, or capacity loss are eliminated.

  • 3. Integration Without Creating Aerodynamic Load

    • Traditional solar panels add thickness to the surface. However, when ultra-thin, flexible solar cells are directly laminated to the composite surface of the fin:

    • Drag does not increase,
    • The weight of the composite fin structure does not change,
    • Structural integrity is preserved.

    Compatibility is quite high, especially with fiberglass, carbon fiber, or polycarbonate fins.

  • 4. Thermal Management Advantage

    • Solar panels heat up slightly during flight and this heat disperses on the fin surface. This can provide extra rigidity at low temperatures in very thin composite surfaces.

Technical Application: How is it Integrated?

There are three basic methods in using integrated solar panels on fins:

  • Ultra-thin flexible panel lamination

    • Flexible solar cells a few microns thick are embedded into the outer surface of the composite fin.

  • Surface-coated photovoltaic film

    • Micro PV surface coated with transparent protective film that can also be compatible with riblet coatings.

  • Embedded cell integration

    • Embedding the panel into the composite layer during fin production.

The electronic module is powered by an ultra-lightweight DC-DC regulator inside the fin or inside the body.

Performance Scenario: Battery-Free Rocket Electronics

When appropriate solar panel selection is made:

  • Telemetry system: low power (100–300 mW)
  • GPS module: 30–50 mW
  • Flight computer: 50–150 mW
  • Sensors: 10–40 mW

Total power requirement is around 0.2–0.6 W.
Even 2 micro panels on the fin can easily meet this power. This eliminates or minimizes the rocket's complete battery need.

Future Perspective

Fin-based solar panels can open the door to many new designs from amateur rockets to advanced flights. Especially:

  • Lightweight, completely battery-free telemetry modules
  • Sensor systems that continuously charge on the launch pad
  • Energy sustainability in long-duration test flights
  • Self-powered flight computer designs similar to micro satellites

innovations like these become much more applicable.