SPRINT Hot Fire Test - December 15th and 16th, 2025

Hardware setup began on December 15th. One hot fire was completed on December 16th in approximately -5 °C ambient conditions.

Propellant Conditions

The nitrous supply cylinder remained outside for approximately 2.5 hours before heating began. With a heater and fiberglass insulation, its pressure increased from approximately 400 psi to 800 psi in 1.5 hours. The vehicle oxidizer tank was not heated. At peak thrust, its telemetry channel read 264 psi; at peak chamber pressure, it read 256 psi.

Measured Result

The run reached 510.0 N peak thrust and 107.2 psi peak chamber pressure. At the thrust peak, the fuel-tank pressure channel read 265 psi. At the chamber-pressure peak, it read 253 psi. Performance was below the intended condition because the vehicle-side oxidizer was cold and underpressurized.

Failure and Corrective Actions

The team's post-test notes characterized the cold-feed run as oxidizer-rich and recorded residual fuel in the system. During the telemetry state labelled Post-ignition Purge, both main-valve command channels remained at 100%. The nitrogen purge expelled the residual fuel, which ignited outside the chamber. The recorded corrections were to heat the vehicle tank, begin supply-cylinder heating earlier and close the fuel valve before purge.

Test Video

Test Data

Burn Telemetry