What is IWFNA?
Inhibited White Fuming Nitric Acid (IWFNA) is a powerful oxidizer used in hypergolic propulsion systems. It consists of nitric acid (HNO₃) with inhibitors added to reduce corrosion and improve stability during storage and handling.
Chemical Composition
- Nitric Acid (HNO₃): 70-90%
- Nitrogen Dioxide (NO₂): 5-15%
- Water (H₂O): 2-5%
- Inhibitors (typically HF): 0.5-1.5%
Key Properties
- Density: 1.50-1.55 g/cm³
- Boiling Point: 83°C
- Freezing Point: -42°C
- Specific Impulse: 250-280 seconds (with amine fuels)
- Hypergolic: Spontaneous ignition with amine fuels
Advantages
- Hypergolic ignition - no ignition system required
- High density - compact propellant tanks
- Excellent specific impulse
- Reliable performance across temperature ranges
- Proven flight heritage in numerous missions
- Compatible with various fuel formulations
Safety & Handling
IWFNA is a strong oxidizer and corrosive substance requiring specialized handling:
- Requires compatible materials (stainless steel, titanium)
- Must be stored in sealed, inert containers
- Proper ventilation and safety equipment required
- Regular inspections for degradation
- Trained personnel for handling and loading
Applications
Related Technologies
Learn more about hypergolic propulsion systems and fuel options:
Applications
IWFNA is used in:
- Orbital maneuvering systems (OMS)
- Reaction control systems (RCS)
- Satellite propulsion
- Deep space probe propulsion
- Upper stage engines