Space Technology Special Report - Version B. July 2023 - 16

Flight Software
Flight software engineers at the Laboratory for Atmospheric and Space Physics at the University of Colorado Boulder were tasked with developing the onboard
software for NASA's new Climate Absolute Radiance and Refractivity Observatory (CLARREO) Pathfinder Reflected Solar mission. (Image: NASA)
orbit necessitated the software
run on a single Arm Cortex-M1
microprocessor instantiated at 50
megahertz (MHz) inside a radiationtolerant
field-programmable gate
array (FPGA) (Microchip RTG4), with
only 4MB of RAM. The engineers
quickly realized that existing flight
software solutions at LASP were not
equipped to handle this combination
of hard real-time performance and
heavy multitasking within such a
constrained processing environment.
To meet these challenges, LASP
undertook the development of a new
software framework with a focus on
three core objectives: high performance,
reliability, and reusability. The
framework needed to produce code that
was not only efficient and deterministic
16 JULY 2023
but also capable of executing parallel
to maximize performance on the
sluggish computing platforms available
for spacecraft. Required to sustain
autonomous operation onboard the
ISS for several years, the software
needed to be high quality and free
of defects. With future missions at
LASP likely to demand even greater
capabilities, the framework also needed
to include a mechanism for effective
transfer and reuse of flight-proven
code from one mission to the next.
Developing Adamant
What was created is a
component-based and model-driven
framework called Adamant.
Prior to writing code, engineers
employ a straightforward domainspecific
modeling language to describe
the architecture of their system.
Architectures consists of a collection
of tightly scoped components, each
performing a specific function, that
have no compile-time dependencies
on one another. To maintain efficiency,
components communicate with one
another, point-to-point, through
strongly typed " connectors. " Features
are organized into components
following the principle of separation
of concerns. Mission-specific code is
implemented in components distinct
from those components intended to
be reusable for future missions.
Adamant models not only describe
components and their connections but
also specify essential elements such
as data types, commands, telemetry,
SPACE TECHNOLOGY SPECIAL REPORT

Space Technology Special Report - Version B. July 2023

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