This slide presentation reviews the process of the evaluation of window placement and configuration for the cockpit of the Lunar Electric Rover (LER). The purpose of the evaluation was to obtain human-in-the-loop data on window placement and configuration for the cockpit of the LER

Howard, Robert

Litaker, Harry

Thompson, Shelby

NASA Technical Reports Server

Determining Window Placement and Configuration for the Small
Pressurized Rover (SPR)
Shelby Thompson, Ph.D.
Harry “Chip” Litaker
Usability Testing and Analysis Facility (UTAF)
Lockheed Martin
Robert Howard, Ph. D.
Johnson Space Center, NASA
https://ntrs.nasa.gov/search.jsp?R=20090040245 2019-08-30T08:14:09+00:00Z
Contributors
Rich Szabo
	 Evan Twyford
Habitability Design Center (HDC)
	 Carl “Chip” Conlee
Lockheed Martin
	 Habitability Design Center (HDC)
MEI Technologies
Page No. 2
Background
• The rover began development in 2007 in order to test the concept of
a multiple wheeled vehicle that had the ability to move in any
direction upon the lunar surface
• Allows the user to “keep an eye” on a target while being able to
navigate over various terrains
• Two versions were designed using the same chassis (a) an
unpressurized “Apollo”-style rover and (b) a small pressurized rover
(since become known as the Lunar Electric Rover, LER)
Page No. 3
Background
• An enclosed cabin was suggested that used suit ports to enter and
exit the vehicle for EVA, includes a side hatch that would be used
docked to a Lunar outpost or another rover
Page No. 4
Purpose of Evaluation
• The purpose of the evaluation was to obtain human-in-the-loop data
on window placement and configuration for the cockpit of the LER
• A baseline window placement and configuration was developed
from the results
• This baseline does not reflect a flight-rated vehicle and ignores critical
issues such as structural integrity, thermal factors, weight, mass, etc.
• A decision was made not to limit the participants in where they
could place and configure the windows
• It was assumed that given the landscape of the lunar surface that
persons would want a wide forward views for navigation over and
around objects, sides windows for docking maneuvers, lower/corner
views for obstacle avoidance at the wheels, and lower/forward views for
geological observations
Page No. 5
Method of Evaluation
•
•
Nine SMEs participated (7 males and 2 females)
• Astronauts, geologists, and engineers
• Each was experienced with current and prior LER configurations
The evaluation took place in the Reconfigurable Operational
Cockpit (ROC) at Johnson Space Center, NASA
• Ability to project a 2-D image on a domed screen
• A medium to high resolution lunar environment was developed using
actual lunar images of the surface
• Due to the size of the LER mockup in the dome, no side views of the
images were available
• Participants sat in the left cockpit seat and controlled a joystick
mounted on the right to “drive” the vehicle over the lunar surface
• The projection included flat to mountainous terrain with craters, rocks,
and boulders
Page No. 6
Method of Evaluation
• The LER mockup was constructed of wood and formcore board
• Several options were considered to evaluated the placement and
configuration of the windows (i.e., head and eye-tracker), but were
rejected for several reasons
• Lack of portability of the head and eye-tracking system
• Not enough led-time to develop the cockpit’s “virtual bubble” that would
simulate the surface of the LER’s front-nose section
• Environment was not optimal for video camera use (dim to low lighting)
and structure did not support the use of a magnetic head tracker (metal
used in the mockup and the ROC)
• Decision was made to create a “grid” that covered the entire front
cockpit with letters and numbers to denote a specific area of the grid
Page No. 7
ROC and LER Mockup
Page No. 8
Data Collection
of necessity
• Using combined images of the cockpit, from the POV as if you were
sitting in the center of the vehicle, a composite image was created
and printed on transparency
• Participants colored in areas they felt were necessary areas for
windows – red (high priority/must have), green (like to have), and
blue (low priority)
• Ten areas were rated (1 = unnecessary to 5 = necessary) in terms
Page No. 9
Results
• Different areas were rated as more necessary depending on the
simulated terrain tested
• For example, upper corners were rated more necessary for
mountainous terrain, while sides were rated high for rock avoidance
and crater inclines
Means for Task by Rover Area for Necessity of Windows
Task Upper Corners Sides Side Arch Front Lower Corners Lower Front
Smooth Flat 1.67 1.50 4.44 5.00 1.44 1.33
Hilly Terrain 1.44 1.78 4.56 5.00 2.11 1.44
Mountain Terrain 3.50 1.89 5.00 5.00 1.67 1.56
General Rock Field 1.00 2.00 4.89 5.00 2.67 2.22
Rock Avoidance 1.00 2.28 4.94 5.00 2.67 1.67
Circling Rock 1.00 1.38 4.69 5.00 2.13 1.88
Crater Incline 2.13 3.00 4.88 5.00 2.13 1.88
Overall Rating 2.22 2.78 4.89 5.00 2.67 2.33
Grand Mean 1.75 2.07 4.79 5.00 2.19 1.79
Note. 1 = unnecessary, 3 = neutral, 5 = necessary
Page No. 10
the windows
Results
• We took the intersection, or congruent, of all red, green, and blue
areas to determine the approximate placement and configuration of
Page No. 11
Where is the LER now?
• Since this study, the cabin 1 a was developed, created, and tested
• A revised cabin 1 b has designed, build, and tested based on human
factors recommendations
Thank You
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Determining Window Placement and Configuration for the Small Pressurized Rover (SPR)

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