Tech Briefs Magazine - December 2022 - 21

The concept offers several
important advantages.
Compared to using capillary
forces to move molten
metal, transporting metal
ions via electrochemical
potential is fast and easy to
control, without the need
to heat the fuel. Alloying
the solid silver fuel source
with nonmobile metals
(e.g., copper, aluminum)
provides an easy means to
enhance self-diffusion of
the silver. The vacuum-compatible
electrolyte film rapidly
transports ions with liquid-like
conductivity at near
room temperatures (25 °C
vs. >150 °C in conventional
systems).
tremely high mass-to-charge
functionality.
Ag+ emission
plume
Extractor
grid
This simple, highly controllable
design
consumes
less energy than liquid-metal
microthrusters and offers
several other significant advantages.
Because
Ch.
solid
electrolyte
Ag
reservoir
Ag film
Si substarte
A covalently bonded chalcogenide solid electrolyte film transports the silver
ions to the emitter tip via an applied electric field, creating the thrust
plume. (Image: NASA)
Fuel transport is not dependent
upon emitter tip geometry, which reduces
the variability in thrust from one
tip to another. With an ion-to-electron
emission ratio of 1:1 - a ratio that cannot
be achieved with the clusters of
ions and droplets in liquid-metal microthrusters
- this system offers exthrusters,
electrospray
thrusters are more efficient
than ion and Hall
electrostatic
this
concept is expected to provide
a unique capability for
in-space
precision
propulsion
for a wide range of
space missions.
NASA is actively seeking
licensees to commercialize this
technology. Please contact NASA's
Licensing Concierge at
Agency-Patent-Licensing@
mail.nasa.gov or call at 202-358-7432 to initiate
licensing discussions. For more information,
visit https://technology.nasa.gov/
patents.
Spacecraft to Remove Orbital Debris
A concept to allow autonomous capture of debris in low-Earth orbit.
Johnson Space Center, Houston, TX
I
nnovators at NASA Johnson Space
Center have designed an Active Debris
Removal Vehicle (ADRV) that
can remove large orbital debris from
low-Earth orbit (LEO). The ADRV
will approach a debris object, assess
its characteristics and motion, determine
an initial capture trajectory,
match its rotation rates, execute a
capture maneuver, and control and
deorbit the object.
The ADRV incorporates several
NASA inventions including a novel
spacecraft control system, debris object
characterization system, and capture
and release system. These NASA ADRV
technologies may also be applied to satellite
servicing and orbital adjustments.
The concept yields a single use, lowDIA
3.448m
cost, lightweight, high mass fraction vehicle
that enables the specific removal
of large orbital debris (1000 - 4000 kg
mass, 200 - 2000 km altitude, and 20 98-degree
inclination). The ADRV performs
rendezvous, approach, and capture of
non-cooperative tumbling debris objects,
maneuvering of the mated vehicle, and
controlled, targeted reposition or deorbit
of the mated vehicle.
Tech Briefs, December 2022
Due to its small form factor, eight ADRVs can be clustered
in a single launch vehicle payload. Each vehicle can
be assigned to a unique debris target. (Image: NASA)
Due to its small form factor, up to eight
ADRVs can be launched in a single payload,
enabling high impact orbital debris
removal missions within the same inclination
group. Three key technologies were
developed to enable the ADRV: 1) The
spacecraft control system (SCS) is a guidance,
navigation, and control system that
www.techbriefs.com
provides vehicle control during all
phases of a mission; 2) The debris object
characterization system (DOCS)
characterizes movement and capture of
non-cooperative targets; and 3) The
capture and release system (CARS) allows
the vehicle to capture and mate
with orbital debris targets.
These technologies can improve the
current state-of-the-art capabilities of
automated rendezvous and docking
technology significantly for debris objects
with tumbling rates up to 25 degrees
per second. This approach leverages
decades of spaceflight experience
while automating key mission areas to
reduce cost and improve the likelihood
of success. It can help mitigate catastrophic
collisions with debris involving
astronauts, their spacecraft, and other
valuable space assets.
NASA is actively seeking licensees to
commercialize this technology. Please
contact NASA's Licensing Concierge at
Agency-Patent-Licensing@mail.nasa.gov
or call at 202-358-7432 to initiate licensing
discussions. For more information, visit
https://technology.nasa.gov/patent/
MSC-TOPS-90.
21
https://technology.nasa.gov/patents https://technology.nasa.gov/patents https://technology.nasa.gov/patent/MSC-TOPS-90 http://www.techbriefs.com
Tech Briefs Magazine - December 2022

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