TNK
type: Concept
in scheme: instruments
definition: The GRACE Cold Gas System uses Nitrogen as medium, which is stored in two tanks at an initial pressure of 350 bar. This upstream pressure is reduced to the thruster valve working pressure of approximately 1.5 bar by a Pressure Regulator. For redundancy reasons, the two branches can be operated individually. Attitude control around the roll, pitch and yaw axis is performed by 3 sets of 4 thrusters with a nominal thrust force of 10 mN. The attitude control thrusters are nominally operated in pairs which are accommodated such, that force free reaction control is achieved. For orbit maintenance, two 40 mN thrusters are mounted on the anti-flight direction side with the force vector pointing through the satellite center of gravity. The cold gas system housekeeping sensor set consists of two Pressure Transducers, one for the high pressure part and one for the low pressure part, and temperature sensors on both tanks and every thruster. [Summary from GRACE Thruster Specification Document] Group: Instrument_Details Entry_ID: TNK Group: Instrument_Identification Instrument_Category: In Situ/Laboratory Instruments Instrument_Class: Recorders/Loggers Short_Name: TNK Long_Name: cold gas TaNK system End_Group Group: Associated_Platforms Short_Name: GRACE End_Group Online_Resource: http://www.csr.utexas.edu/grace/ Creation_Date: 2007-05-02 Group: Instrument_Logistics Instrument_Owner: USA/NASA End_Group End_Group

Recorders/Loggers
type: Concept