| Lunar Roving Vehicle
The Lunar Roving Vehicle or LRV is a small dune-buggy car
that permitted the Apollo astronauts to drive from the vicinity
of their landing site on the moon to make geological observations,
collect rock/soil samples and use scientific instruments
at various moon locations. The Lunar Rover was first used
during Apollo 15 which launched on July 26, 1971. This was
the fourth lunar landing that permitted human exploration
on the Moon's surface. The LRV was also used during Apollo
missions 16 and 17.
The LRV weighed about 480 earth pounds (80 pounds on the
moon). It could carry two astronauts along with their portable
life support systems and scientific instruments. The LRV
could carry about twice its own weight so there was plenty
of room for the lunar material samples the astronauts collected.
The LRV was designed for low speed and high torque. It was
limited to 8 mph (3.5 meters per second) for safety reasons.
Going over rough lunar surfaces could have been a danger
to the crew. It could climb a 25 degree slope so it could
more easily travel over the uneven surface.
The wheels on the rover were made of wire mesh (piano wire)
with titanium cleats for treads. The engineers did not use
solid or air-filled rubber tires because they would have
been much heavier. The Apollo spacecraft could only carry
a fixed amount of weight (mass) so the wire-mesh wheels
were important for keeping the weight of the vehicle low.
One of the instruments which was carried on the Lunar Rover
was a Traverse
Gravimeter. It was used to measure and map the gravitational
fields on the Moon.
10 feet long
480 Earth pounds
13 inches on level ground
|2 Electric battery systems
4 - 32 inch wheels
|Control stick mounted in vehicle center
||Computes distance and direction to lunar
||Display shows speed in kilometers per
|6 feet wide (1.8 meters)
80 moon pounds
||Electric motor in each wheel.
||Both front and rear wheels steer
||Either astronaut could steer.
||Display shows heading of vehicle,bearing
in degrees,kilometers from module
||Speed up to 8 mph (3.5 meters per second)
7.5 feet wheelbase
||If wheel motor fails it can
be decoupled - others take over to drive LRV.
||Rear or front steering mechanism
can provide full service if one fails.
||System uses angle of sun
and declination of module to set gyroscope before leaving
||Designed for 78 hour life-time
||Uses assumed lunar north to set bearing.
TV - Communications Systems
A color TV camera and communication system that permitted
the astronauts to transmit pictures and voice communications
directly from the vehicle to Earth were carried on board
the LRV. Still-picture cameras were mounted on the chest
of each astronaut for additional pictures. The TV camera
could be controlled remotely from Mission Control Center
Traveling to the Moon
The LRV was folded up and placed inside the lunar module.
The chassis (body) of the LRV is hinged in three places
so it was folded in thirds and the 4 wheels were pivoted
or turned nearly flat against the folded chassis. It occupied
only 30 cubic feet. It was stowed inside the descent stage
of the lunar module in quadrant Number 1 to the right of
the ladder down which the astronauts descended to the Moon's
Lunar Module Descent Stage Diagram
Click diagram for a larger view
The Descent Stage held the lunar
rover during the flight to the Moon.
The Lunar Module traveled to the moon inside this
Lunar Module Adapter.
Click here for a larger
view or to print out a larger diagram.
Once on the lunar surface the LRV could be removed
from the lunar module. The first astronaut would descend
the ladder and remove a contingency cable from quadrant
Number 1. The second astronaut would then pull a D-ring
mounted on the side of the lunar module. By pulling
this, the LRV would be released at the top. The first
astronaut would then pull a series of cables which
would lower the LRV from the lunar module and unfold
it as it moves to the Moon's surface. Once on the
surface with the four wheels deployed, the astronauts
would mount the camera, and load equipment and scientific
gear to prepare for the lunar trip.
Astronauts drove within a radius of the lunar module
from which they could walk back should the LRV break
down. Even so, some 50 square miles of exploration
The LRV was designed to have a 78 hour life-time
during the lunar day where the temperature in the
sun was 243 degrees F and shadows where the temperature
plunged to -279 degrees F.
For more information see the NASA
Lunar Rover site.