Avionics News - September 2023 - 50

L3HARRIS' AVIONICS MOON SHOT
Continued from page 49
on L3Harris equipment for rocket thrust control on
descent and ascent.
The company also provides the pyro-initiators for booster
and solid rocket booster staging events. Pyro-initiators fire the
shaped-charge explosives to separate the solid rocket boosters
from the launch vehicle after their fuel is expended. Finally,
when it is time for the second stage to separate from the lower
stage, L3Harris provides the pyro-initiators that set off
that explosive charge. It also provides for other vehicle
separation events during the course of the flight.
The company also provides safety devices that are used
in an emergency to terminate the flight. The autonomous
flight termination system aboard the spacecraft will
determine autonomously if the vehicle is malfunctioning,
eject the manned capsule to safety and destroy the
vehicle. An astronaut safety system allows the capsule and
astronauts to communicate with the boost vehicle in the
event of a complete vehicle power failure.
" Our 60-year history of supplying dependable launch
avionics makes us the right supplier for Northrop
Grumman, Boeing, and the Space Launch System and the
Artemis missions returning humans to the moon, " said
Kristin Houston, president, Electro Optical, L3Harris. " We
are committed to accelerating our processes to deliver
booster avionics that safely support the Artemis mission. "
L3Harris has been providing products to NASA since
the early days of the space program from Mercury to
Gemini to Apollo followed by the Space Shuttle, the
International Space Station and Mars missions. The
company has 47,000 employees and $17 billion in annual
revenue. It also supports space-based weather forecasting
on satellites and has navigation technology aboard every
U.S. GPS satellite. And it provides a GPS navigation
tracking unit on Artemis to track the path of the vehicle
and allow for corrections.
Thinking back to Apollo 11, when Neil Armstrong and
Buzz Aldrin walked on the moon for the first time on July
20, 1969, America and the rest of the world were enthralled
with the achievement. People were fascinated by the video
and still photos, including one of the Earth seen from the
surface of the moon. It was more than just an aerospace
engineering feat. Life magazine even hired noted poet
James Dickey to peruse the meaning of it all. He served as
a radar operator of a P-61 Black Widow fighter during raids
over Japan near the end of World War II.
One can imagine the international sensation stoked by
the media when American astronauts walk on the moon
again two years from now in 2025 if things go as planned.
Several of the proposed lunar landers will also be relying
50 avionics news * september 2023
" L3Harris has sophisticated engine controllers on lunar
landers to provide fuel flow and control rocket thrust, "
said Mark Dapore, an engineering fellow and chief
technologist at L3Harris. " Every mission that is manrated
has a set of quality and test requirements, which
are designed to keep the astronauts safe in the event of
malfunctions. This involves redundant systems, which
can take over in the case of failures or malfunctions in
other portions of the system. " L3Harris gathers data on
performance of its systems, digitizes the data and sends
it from RF transmitters to mission control. " Today's
advanced microcircuits not only have better self-test and
fault tolerance, but they are lighter and more reliable, "
Dapore said. " They provide better control of the vehicle
and allow us to send more data back to mission control. "
Dapore was formerly general manager of the space
avionics division that designs and makes launch vehicle
control avionics, command receivers, transponders,
telemetry transmitters, payload transmitters and data
acquisition units for use on orbital and deep space
satellites and launch vehicles.
The business unit that makes all this space-qualified
equipment at L3Harris lives in a world where a single point
of failure risk is not an option. Redundancy is a way of life
in the space business. The Federal Aviation Administration
requires commercial aircraft to be single-fault tolerant while
pyro-initiators have to be two-fault tolerant, meaning they
have to be able to work at precisely the right time even after
two faults. The environment in which avionics perform for
space launches is extremely demanding. Commercial jets fly
in an environment that can produce 10 G-forces or less while
a space launch can produce 50 G-forces.
For unmanned missions, single-fault-tolerant
requirements mean that there can be a single fault
anywhere in the vehicle and the mission will continue.
Human missions require that missions can continue with
two faults, and a three-fault tolerant requirement is set if
malfunctions can lead to a loss of life. Additional units can
provide redundancy, but then there is a requirement for
fault detection and correction. " Fault detection can actually
detect hazards than can occur during the course of the
mission and take appropriate action, " Dapore said. " So it
is more than just having a redundant system take over. The
system can actually redirect the mission to provide safe
passage for the astronauts. "
Anyone who has read about or watched the movie
Apollo 13 and the explosion that created a huge
challenge to the safe return of the crew can appreciate
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