Spender Cold-Flow Attempt 1 - January 21st–22nd, 2023
This was the first major integrated checkout of Spender's tanks, plumbing, pneumatics, controls and ground equipment.
Test scope
The first day was used to integrate the plumbing, pneumatics, control hardware and ground equipment at the test site. Pressurization began on the second day. Remote control and telemetry were demonstrated, but propellant loading, cold flow, purge and tank-mass measurements were not completed.
Failure and outcome
The attempt was scrubbed during pressurization when the stem seal on the first pressurant control valve failed. The valve's packing nut and washer had been omitted during assembly. Downstream isolation and vent valves prevented the failure from propagating through the rest of the system, and no flow occurred. The same valve later passed pressure testing in May, confirming that the January failure was an assembly error rather than a failed valve body.
The temporary push-to-connect pneumatic plumbing also leaked repeatedly above 100 psig. Several fittings were difficult to reach after the system was assembled, and the coupling fit was tight enough that parts had been sanded or driven together during integration.
Corrective actions
The rebuild replaced the temporary pneumatic tubing with hardline copper and added a compressed-air supply. The team also revised coupler and packing tolerances, required standalone high-pressure tests before integration, and added dry runs, inventories, clean-handling rules and assembly training to the test procedure.
