PHASA-35 is a 35m-wingspan high-altitude solar-electric HAPS providing months-long endurance, stratospheric persistence, and 15 kg payload for ISR and comms relay.

# BAE Systems PHASA-35 – High-Altitude Solar-Electric HAPS for Persistent ISR and Communications

The PHASA-35 is a high-altitude pseudo-satellite (HAPS) designed by BAE Systems in collaboration with Prismatic. With a 35-meter wingspan and ultra-light composite construction, it operates in the stratosphere for extended periods, enabling persistent ISR, communications relay, and environmental monitoring without the cost of conventional satellites.

1. Solar-Electric Endurance

Equipped with photovoltaic arrays and efficient batteries, PHASA-35 harvests solar energy during the day and sustains flight at night. This capability enables missions spanning days to months, providing uninterrupted situational awareness.

2. Stratospheric Operation

The aircraft flies above 60,000 ft, staying clear of weather disturbances and commercial air traffic, ensuring stable, long-duration operations for ISR and communications tasks.

3. Payload Capacity

PHASA-35 supports up to 15 kg of modular payloads, including EO/IR sensors, communications relays, and bespoke mission-specific sensor suites. The modular payload bay allows flexible adaptation for a wide range of missions.

4. Lightweight and Durable Design

Constructed with ultra-light composite materials, PHASA-35 achieves high strength-to-weight ratio while maintaining the efficiency necessary for long-endurance solar-electric flight.

5. Cost-Effective Persistent Coverage

By operating as a high-altitude pseudo-satellite, PHASA-35 offers a lower-cost, flexible alternative to satellites, delivering continuous coverage for defense, scientific, and communications applications.