Propellant Consumption Control System (PCCS) Ensures the Following

In the calculated-nominal conditions of LV flight the process of propellant consumption from the stage tanks is ensured by calculated-nominal values of useful propellant volume. However, inpracticetheflightofLVisaccompaniedwithdifferentrandom disturbances, effecting the process of propellant consumption. Suchdisturbancesincludeerrorsinthemainenginethrustandpropellants ratio, setting errors in LV tanks loading, aerodynamic parameters of LV, etc.Takingintoaccounttheabovefactors, itisnecessarytohaveacertainpropellant reserve in each of LV tank, in addition to the guaranteed useful propellant volume, which is fully consumed under calculated-nominal conditions during payload injection. The guaranteed propellant reserve is consumed during disturbance modes of flight for compensation of random disturbances, requiring additional power consumption. Allocationofthe guaranteedpropellantreserveoutofthe totalpropellantmass, loadedintoLVtanks, ispossibleonly at the expense of relevant reduction of useful propellant volume, which results in decreasing of LV nominal lifting capacity.

The guaranteed propellant reserve portion, used for compensation of random disturbance, may reach above 5% of the mass of useful propellants volume. The volumeofsuchnon-depletedpropellantsmaybesignificantlyreducedtotheacceptablelevel (~0.3% of the useful propellant volume) by means of using special systems at LVs, generally named as propellant consumption control systems (PCCS).

Propellant consumption control system (PCCS) ensures the following:

-simultaneousconsumption of oxidizer and fuel from LV tanks by the moment of stages engines shutdown;

-full propellant deplition from LV tanks by determining of minimum allowable volume of residual propellant, required only for fail-safe engines shutdown.

The system includes:

- level sensors, installed in propellant tanks of LV;

- systemconvertingandcomputingunit (CCU), designedforprovisionofinteractionwithlevelsensors, solvating the PCCSalgorithm, formation and transition of telemetry data on PCCSoperation into the measurement system. CCU can be implemented as an autonomous on-board device or a part of specific LV control system equipment;

- actuationelementsofPCCS(electric drives and throttles) in the main engines fuel pipeline designed to maintain the propellants mixture ratio within the given range (Km);

- groundcheckoutequipment, designedforinteractionwithon-boardPCCS equipmentduring remote checkout and preparation of the system for a specific flight;

- system harness.

Work schedules:1.5 – 2 years (dependingonthechosenoptionofthe systemhardware implementation)