High-Altitude Pseudo-Satellite (HAPS)
Fixed-Wing UAVThreat: LowOpen-Source Verified
Solar-powered or hydrogen-fueled drone operating at stratospheric altitudes (18–25 km) for weeks or months. Acts as a low-cost alternative to satellites for persistent ISR, communications relay, and signals intelligence. Flies above weather and most air defense systems.
Technical Specifications
range
Stationary (loiters over area of interest)
speed
50–150 km/h (station-keeping)
payload
5–100 kg (sensors, comms relay)
endurance
Weeks to months (solar-powered)
frequency
SATCOM + military datalink
cost Estimate
$5–50 million
altitude
18,000–25,000 m (stratosphere)
weight
50–500 kg
Tactical Roles
ReconnaissanceISR
Advantages
- + Weeks/months of continuous operation — near-satellite persistence
- + Operates above weather and most air defenses
- + Much cheaper than satellites to deploy and replace
- + Provides regional ISR and communications relay
- + Can be repositioned unlike geostationary satellites
Disadvantages
- − Extremely fragile airframe — vulnerable to high winds
- − Very limited payload capacity
- − Cannot survive severe stratospheric weather events
- − Technology still largely experimental
- − Slow response — takes time to reach operational altitude
- − Requires specialized ground support infrastructure
Real-World Usage
- ▸ Airbus/Aalto Zephyr — solar HAPS, 67-day continuous stratospheric flight record (May 2025)
- ▸ BAE Systems PHASA-35 — UK stratospheric HAPS
- ▸ NASA Helios — solar prototype (historical)
- ▸ Chinese Morning Star solar HAPS and US programs in active development
Counters This Drone
Countermeasures ranked by effectiveness — tap any system for details
Counter-UAS Radar SystemMediumRF Jamming SystemLowGPS Spoofing / Navigation WarfareLowCyber Takeover / Protocol ExploitationLowRF Detection / Spectrum AnalyzerLowMedium/Long-Range SAM SystemLowAI Vision Detection (EO/IR)LowPassive RF GeolocationLowHardened PNT / CRPA AntennaLowShotgun / Small Arms InterceptNoneLaser Directed Energy WeaponNoneAcoustic Detection SystemNoneInterceptor Drone (Drone-on-Drone)NoneNet Gun / Net LauncherNoneDirectional EW Rifle / Jammer GunNoneMANPADS (Stinger/Igla class)NoneC-UAS Autocannon / Dedicated AA GunNoneHigh-Power Microwave (HPM)NoneFiber-Optic Specific CountermeasuresNoneSmoke / Obscurant ScreenNoneAnti-Drone Laser DazzlerNoneLocalized EMP DeviceNonePhysical Overhead ProtectionNoneDecoys / Signature ManagementNoneMan-Portable EW BackpackNoneNet-Carrying Interceptor DroneNone