High Speed Simulator - A Simulator for All Seasons

Keyur Patel
Keyur.C.Patel@jpl.nasa.gov
NASA/JPL

Abstract:
This paper will discuss the evolution of the Multimission Ground
Systems Office's (MGSO) High Speed Spacecraft Simulator (HSS)
development at the Jet Propulsion Laboratory.  This paper will
examine the evolution from both a development and operations
perspective.

The High Speed Spacecraft Simulator (HSS) in reality is a series of
simulators capable of modeling the spacecraft and its subsystems at
either the bit or functional level, depending on specific mission
needs.  An initial delivery of the HSS was made to the Galileo
(GLL) Project for the sole purpose of validating the GLL Low Gain
Antenna mission's flight software resulting from the stuck High
Gain Antenna last year.  Due to the excellent performance of the
HSS in assist'mg with the flight software validation additional
opportunities were identified for its use on the GLL Project.
These opportunities modeling of other on-board data systems, e.g.
Command and Data subsystem, Attitude and Articulation Control
subsystem.  In addition to the data system siinulator and the flight
software validation capabilities, GLL has replicated the HSS for
the purposes of sequence validation and anomaly investigation to
name a few.  Because the HSS is a software emulator of the flight
system, the replication costs associated with adding additional
"testbeds" are not only minimal but required no additional
maintenance manpower to support.

The HSS provides an unparalleled set of capabilities and
sophisticated tools for supporting the operational needs of a
project while providing detailed visibility into the internal
workings of the spacecraft.

Today, JPL's MGSO organization is actively developing High Speed
Spacecraft Simulators for both the Cassini and Voyager Projects.

The work described in this paper has been carried out by personnel
at the Jet Propulsion Laboratory, California Institute of
Technology, under contract to the National Aeronautics and Space
Administration.