Making Diagnostic Interferometry Possible: the Need for Data Processing on Spacecraft of the Next Millenium.

M. Rilee (Raytheon ITSS),
S. Curtis,
B. Farrell,
A. Figueroa-Vinas,
J. Houser,
M. Kaiser,
M. Reiner (Raytheon ITSS).
NASA/Goddard Space Flight Center

There is a growing understanding that missions involving multiple
spacecraft are becoming critical for the advance of Space Science. Yet
multispacecraft missions present serious technical challenges,
space-to-ground communication is a critical bottleneck. Space Science
missions probe a rich and complicated environment; current
instrumentation is capable of producing more information than we can
downlink to Earth. When increases in instrument information
productivity, the number of spacecraft, and the number of space
missions are multiplied to obtain the future demand on communication
resources, we see a problem. Current methods of information extraction
from spacecraft sensor data will not scale for the multispacecraft
systems that are necessary for the advance of Space Science. Still,
important, raw sensor data {\it must} be transmitted to Earth for
analysis.

A possible solution to these competing needs is to carefully select
what data is transmitted to Earth. For many missions, this has meant
reducing the mission scope, limiting sensor capability, and limiting
the time during which data is taken. However, these circumstances
render many worthwhile missions infeasible, particularly those using
interferometry to examine the Space Environment. With sufficient
on-board computational and memory resources, data can be manipulated
in place onboard the spacecraft, with some reductions, results, or
synopses of the data being transmitted to Earth. In this work, we
examine the data processing needs of an exceptionally demanding
application, an orbiting {\it Radio Interferometric Array}, that is
being developed for the {\it REE Flight Processor}.

The {\it REE Flight Processor} is a spaceworthy scalable parallel
computer being developed by NASA's High Performance Computing and
Communication Program's Remote Exploration and Experimentation (REE)
Project. The REE Project seeks to capitalize on commercial
supercomputing technology to create an economical, robust,
fault-tolerant processor with exceptionally small mass and power
requirements. We will explore the implications of this new technology
for such fundamentally important diagnostic tools as wave
interferometry.