Crew and Equipment Translation Aid (CETA) Energy
Absorber and Braking Characteristics
Crewmembers aboard the International Space Station
will use the CETA as a means of locomotion outside
of the Station to perform maintenance and repair duties.
The CETA utilizes two types of brakes and has an energy
absorber device attached to it that is designed to
alleviate the impact loads if the CETA reaches the
end of its track. In addition to zero-gravity (
DC-9 Aircraft) testing of the CETA's braking characteristics,
the ABF performed dynamic impact testing of the energy
absorber at the Precision Air Bearing Floor (PABF), during which the energy
absorber was mounted onto a weighted sled/mockup and
impacted a force plate at known velocities.
Locomotion in partial gravity environments (lunar
and Mars)
The ABF was involved in subject testing of an advanced
space suit to evaluate mobility and locomotion in
a Martian gravity environment. These experiments were
performed aboard the
DC-9 Aircraft. The ABF collected
motion analysis data while the suited subjects walked
and performed other physical tasks throughout the
airplane. These data are useful for space suit designers
to understand what characteristics of the suit aid
or hinder locomotion and various essential work activities
in low-gravity environments.
Crew-induced loads while ingressing/egressing a
portable foot restraint
Mission trainers for the upcoming Hubble Space Telescope
servicing missions wanted to know what kind of loads
the crewmembers might impart while getting into and
out of foot restraints attached to the telescope.
To test this, an experiment was conducted by the ABF
during several days of crew training in the
Neutral Buoyancy Lab. A full-size mockup of the Hubble was
placed in the NBL pool, to which one of the ABF's
waterproof force plates was mounted. The force plate
measured the three-dimensional forces and moments
that were imparted when the crewmembers ingressed/egressed
the attached foot restraint. ABF personnel were able
to give the astronauts and mission trainers real-time
feedback on these loads so the astronauts could practice
different techniques to minimize the forces.
Crew-induced loads while donning and doffing a space
suit
Space suit and structural engineers were interested
in finding out what kind of forces astronauts generate
when donning and doffing the Extravehicular Mobility
Unit (EMU). The ABF was tasked to measure these loads
in both one-gravity and zero-gravity (aboard the
DC-9
Aircraft) environments. For both conditions, two
of the ABF's force plates were mounted on an L-shaped
test stand to measure forces at the 'floor' (many
astronauts use their legs/feet to push while donning
the EMU in microgravity) and at the upper portion
of the suit (some astronauts only use their arms to
pull and mate the two portions of the suit in microgravity.
Load Sensing Handrail
The purpose of this study is to develop a mathematical
model to predict and maintain the neutral buoyancy
of suited subjects during training operations at the
Neutral
Buoyancy Lab in order to minimize the occurrence
of off axis moments, loading during extended runs,
and shoulder injury during inverted operations.
Shoulder Injury Project
The goal of this project was to determine and quantify
the effects of the shoulder harness on the pressure
experienced at the shoulders of suited crew members.
Pressure data (Xsensor)
were collected during various upper body motions for
both unpressurized and pressurized conditions. The
pressure data were analyzed for both harness and no
harness conditions.
Low Impact Docking System
Structural engineers designing the requirements for
the Crew Exploration Vehicle (CEV) were interested
in finding out the minimum dimensions that allowed
a suited crew member enough clearance to translate
through the Low Impact Docking System (LIDS) and the
CEV side hatch without catching the suit on protrusions.
The ABF was tasked to determine whether a suited crewmember
could translate through the proposed LIDS diameter
or if a revision would be needed to the CEV plans.
Both openings were tested with mockups while 5 of
the ABF’s digital video cameras recorded the
trials for post-processing using video analysis software.
Low-Volume Airlock Mockup
This test explored the minimum volume needed for
two exploration airlock concepts. The ABF was tasked
to perform initial motion analysis to provide measurements
needed to fabricate higher-fidelity mockups used to
determine and verify airlock dimensions. Using innovative
motion capture techniques, the ABF was able to visualize
the motion of a subject through a virtual airlock
opening and confirm the opening could accommodate
the Mark III prototype suit. Additionally, a seated
airlock concept was explored. For these tests, an
ABF test subject was seated on an inclined seated
airlock mockup and performed various tasks such as
reaching for controls, ingress, and egress.
Jettison
The goal of this project was to collect motion (Phoenix
Technologies) data simulating the jettison of
an Early Ammonia Servicer (EAS) from the International
Space Station. This data was used to evaluate the
astronaut corps ability to control the trajectory
of the large EAS while generating a minimal release
velocity of 0.1 m/s or greater. The EAS serves as
a reservoir of coolant in the event of a leak of coolant
onboard the space station.
