DEFIANT Small Satellite Bus
Space Flight Laboratory (SFL)
Flight-proven 20–35 kg 27U-format bus for HawkEye 360, NorSat-4, and DND Grey Jay missions. Up to 30 kg payload, S/X-Band comms, multiple propulsion options.
Technical specifications
- Mass
- 20–35 kg
- Dimensions
- 300 × 300 × 400–450 mm (27U form factor)
- Payload mass
- Up to 30 kg
- Payload volume
- 11,000 cm³
- Peak power
- 50–100 W (body + 2 deployable solar wings)
- Payload power
- 45 W @ 40% duty cycle min; 65 W max
- Pointing accuracy (mag)
- ~2°
- Pointing accuracy (star tracker)
- 10–60 arcsec
- Propulsion options
- Cold gas, resistojet, monopropellant, iodine electric
- Communications
- UHF/VHF/S-Band/X-Band; 32 kbps–50 Mbps downlink
- GPS navigation
- 5–10 m accuracy
- TRL
- 9 (flight-proven)
- Notable missions
- NorSat-4, NorSat-TD, HawkEye 360, DND Grey Jay
About
The DEFIANT is SFL’s medium-small satellite bus, bridging the gap between nanosatellites and larger platforms. At 20–35 kg in a 300×300×400-450 mm (27U) form factor, DEFIANT supports demanding Earth observation, RF geolocation, maritime surveillance, and defence missions with a robust payload capacity of up to 30 kg and 11,000 cm³ of payload volume.
Attitude control options span passive (magnetic + fine sun sensors + reaction wheels, ~2° accuracy) to precision (star tracker, 10–60 arcsec), and propulsion options include cold gas, resistojet, monopropellant, and iodine electric. Communications are configurable across UHF/VHF, S-Band, and X-Band at 32 kbps to 50 Mbps downlink. Flight missions include NorSat-4 (AIS + low-light Arctic imaging, January 2025), NorSat-TD (ion propulsion + laser comms demo), HawkEye 360 RF-geolocation cluster, and DND Grey Jay surveillance satellite.
Documentation
No public datasheet yet — request the datasheet / ICD from the supplier.
