Space Telecommunications Radio
NASA’s Space Communication and Navigation (SCaN) Office has developed
an architecture standard for SDRs used in space and ground-based platforms
to provide commonality among radio developments to provide enhanced
capability and services while reducing mission and programmatic risk.
The Space Telecommunications Radio System (STRS) architecture standard
defines common waveform software interfaces, methods of instantiation,
operation, and testing among different compliant hardware and software
products. These common interfaces within the architecture abstract,
or remove, the application software from the underlying hardware to
enable technology insertion independently at either the software or
• Define an open architecture to provide software portability
and re-use, scalability, and H/W, S/W independence to future SDR
– Reduce risks with proprietary, custom SDR implementations
– Leverage investments among SDR developments – Accommodate
advances in technology insertion – Reduce dependence on application
• Develop architecture reference implementations for testing
• Infuse SDR technology and a common radio architecture into
flight demonstrations and appropriate mission classes
• Establish baseline open architecture definition • Characterize
the architecture’s functions, flexibility, and
• Incorporate state-of-art SDR technologies to advance the
next generation SDR
• Participate on industry and Government technology working
group to define open architecture standards for space-based radios
• Leverage existing or developing standards, resources, and
Glenn Research Center is one of the lead NASA centers for
software defined radio (SDR) architecture and technology
in support of the Space Telecommunication Radio System (STRS).
For the past four years, Glenn’s Digital Communication Branch
has been defining the STRS Architecture and evaluating SDR
technology from various vendors for application in future
The STRS architecture will provide a common framework across
different NASA missions and allow the portability of space
radio software among small or large platforms, providing
a flexible, scalable architecture. The STRS architecture
enhances the flexibility of space communication by allowing
space radio functions to reside in the software instead of
the hardware. SDR converts analog signals to digital data
for manipulation and transmission.
In this effort, Glenn has partnered with the Jet Propulsion
Lab, Goddard Space Flight Center, Johnson Space Center and
NASA Headquarters to form the SDR Architecture Team (SAT).
Glenn’s role includes leading the definition of the architecture
and technologies and the SDR prototyping. The architecture
is then applied to the SDR prototypes for evaluation and
refinement of the architecture.
A radio runs applications referred to as waveforms, which
include all the functions necessary to transmit information
from one radio to another. The figure on the right illustrates
an example of the software abstraction definition between
the waveform application and the radio operating environment.
The architecture framework requires that vendors publish
a hardware interface definition to provide a physical definition
of the hardware interfaces for subsequent module integration.
SDR offers many benefits to the space program. If requirements
change prior to a launch, the software can be changed faster
and easier than hardware. Changes can be made if a failure
occurs on orbit and if the software is able to compensate
for unexpected issues elsewhere in the communication system.
The software may also be reconfigured to perform multiple
processes on the same piece of hardware. Therefore, less
hardware is needed, which reduces the total weight and cost
of space hardware.
Glenn is planning to test the STRS architecture on a space
station experiment, scheduled for launch in 2010. Their efforts
will result in an agency-wide standard for the new architecture
between 2010-2012. Commercial standards organizations and
their member companies are contributing to the STRS architecture
through the Objective Management Group (OMG) and the Software
Defined Radio Forum.
Space Telecommunications Radio System News