Flight Firing Operations on the ITALSAT F1 R-4D-11 Thruster 911413
This Paper summarizes the main results of the firing operations performed by the Liquid Apogee Engine (LAE) of ITALSAT F1 spacecraft that has been launched Jan. 15,91.
This evaluation represents the final check step of the thermal design activities on the LAE & Thermal Shield Assembly and of the firing control strategy definition presented on the Paper:
“Thermal Design, testing and firing control strategy of the Liquid Apogee Engine & thermal Shield Assembly for the ITALSAT program” included in the SAE's 20th ICES conference (1990).
The ITALSAT mission has been characterized by two LAE firing operations to place the spacecraft in the final geosynchronous orbit; each firing duration being about 37 minutes.
The firing operations were controlled by means of a dedicated procedure which includes a combination of continuous monitoring of the LAE temperatures, verifications with respect to defined redline limits and projections of the steady state temperature levels for both the LAE Flange (primary sensor) and Fuel Valve (redundant).
The Paper constitutes a summary of the obtained flight data and of the technical considerations coming from the comparison of such data with the pre-flight estimate.
The refined Firing Control criterion is also presented pointing out the differences with respect to the previous Paper and adding the relevant rationale.