Liquid Test Stand

The liquid test stand (LTS) began as a variation of the original hybrid test stand. The LTS supports cold flow and hot fire operations for Lotus Development engines.


All hazard operations can be operated remotely using servo, pneumatic, and solenoid valves. Fluid systems include high pressure nitrogen, liquid nitrous oxide, and liquid isopropyl alcohol. The water suppression system is included for hot fire operation.

The main feed system consists of 1" lines, along with a 1" pre-valves and 1" main valves (liquid Cv of 13). The main feed system operates at a liquid CdA of 0.23in2 (8.7 liquid Cv). The propellant feed allows for flow rate measurements via turbine flow meters.

The main valves run off of a high pressure pneumatics system operating at 1000psi. Solenoid valves allow for reliable and quick operation of the main propellant valves. 

Engine purge operates at 150 psi, and is controlled via a servo operated ball valve. The line is orificed to control flow rate and purge pressure.

The propellant run tanks are pressurized via a bang-bang nitrogen controller and can hit a pressure bound of +/- 15 psi nominal operating pressure. Propellant tanks each contain pressure relief valves that open to release pressure when the tanks run above 1000psi.