Moon Buggies ( just the facts - a article written in 2007)
The Lunar Roving Vehicle (LRV) or Lunar rover is a land vehicle used on the Moon. Several Apollo Lunar Module spacecraft delivered lunar rovers to the moon.
History
The
original cost-plus-incentive-fee contract to Boeing (with Delco as a major sub-contractor)
was for US$19 million & called for delivery of the first LRV by April 1, 1971,
but cost overruns led to a final cost of US$38 million. Four lunar rovers were
built, one each for Apollos 15, 16, & 17, & one that was used for spare
parts after the cancellation of further Apollo missions. There were other LRV
models built: a static model to assist with human factors design, an engineering
model to design & integrate the subsystems, two 1/6 gravity models for testing
the deployment mechanism, a 1-gravity trainer to give the astronauts instruction
in the operation of the rover & allow them to practice driving it, a mass
model to test the effect of the rover on the LM structure, balance & handling,
a vibration test unit to study the LRV's durability & handling of launch stresses,
& a qualification test unit to study integration of all LRV subsystems.
LRVs were used for greater surface mobility during the Apollo program J-class missions: (Apollo 15, Apollo 16, & Apollo 17). The rover was first used on July 31, 1971 during the Apollo 15 mission. This greatly expanded the range of the lunar explorers. Previous teams of astronauts were restricted to short walking distances around the landing site due to the bulky space suit equipment required to sustain life in the lunar environment. The rovers have a top speed of about 8 mph.
The LRV was developed in only 17 months & yet performed all its functions on the Moon with no major anomalies. Harrison Schmitt of Apollo 17 said, "....the Lunar Rover proved to be the reliable, safe & flexible lunar exploration vehicle we expected it to be. Without it, the major scientific discoveries of Apollo 15, 16, & 17 would not have been possible; & our current understanding of lunar evolution would not have been possible."
The LRVs did experience some minor problems, however. The rear fender extension on the Apollo 16 LRV was lost during EVA2 at station 8 when Young bumped into it while going to assist Duke. The dust thrown up from the wheel covered the crew, the console, & the communications equipment. High battery temperatures & resulting high power consumption ensued. No repair attempt was mentioned. The fender extension on the Apollo 17 LRV broke when accidentally bumped by Eugene Cernan with a hammer handle. The crew taped the extension back in place, but because of the dusty surfaces, the tape did not adhere & the extension was lost after about 1 hour of driving, causing the astronauts to be covered with dust. For the second EVA, a replacement "fender" was made with some EVA maps, duct tape, & a pair of clamps from inside the Lunar Module - nominally used for the moveable overhead light. This repair was later undone so that the clamps could be brought back inside for launch. The maps were brought back & are now on display at the National Air & Space Museum. The abrasion from the dust is evident on some portions of the makeshift fender.
NASA's rovers have been abandoned & thus belong to the list of artificial objects on the Moon. Also on that list are the Soviet Union's unmanned rovers named Lunokhod 1 & Lunokhod 2.
Features &
specifications
The Apollo Lunar Roving Vehicle was an electric vehicle designed
to operate in the low-gravity vacuum of the Moon & to be capable of traversing
the lunar surface, allowing the Apollo astronauts to extend the range of their
surface extravehicular activities. Three LRVs were driven on the Moon, one on
Apollo 15 by astronauts David Scott & Jim Irwin, one on Apollo 16 by John
Young & Charles Duke, & one on Apollo 17 by Gene Cernan & Harrison
Schmitt.
Usage
Each rover was used on three traverses, one per day
over the three day course of each mission. On Apollo 15 the LRV was driven a total
of 17.25 miles in 3 hours 2 minutes of driving time. The longest single traverse
was 7.75 miles & the maximum range from the LM was 3.1 miles. On Apollo 16
the vehicle traversed 16.5 miles in 3 hours 26 minutes of driving. The longest
traverse was 7.2 miles & the LRV reached a distance of 2.8 miles from the
LM. On Apollo 17 the rover went 22.3 miles in 4 hours 26 minutes total drive time.
The longest traverse was 12.5 miles & the greatest range from the LM was 4.7
miles. An operational constraint on the use of the LRV was that the astronauts
must be able to walk back to the LM if the LRV were to fail at any time during
the EVA. Thus, the traverses were limited in the distance they could go at the
start & at any time later in the EVA. Therefore, they went to the furthest
point away from the LM & worked their way back to it so that, as the life
support consumables were depleted, their remaining walk back distance was equally
diminished.
Mass & payload
The Lunar Roving Vehicle had a mass
of 463 lbs & was designed to hold a payload of an additional 1,080 lbs on
the lunar surface. The frame was 10 feet long with a wheelbase of 7.5 feet. The
maximum height was 3.75 feet. The frame was made of aluminum alloy 2219 tubing
welded assemblies & consisted of a 3 part chassis which was hinged in the
center so it could be folded up & hung in the Lunar Module quad 1 bay. It
had two side-by-side foldable seats made of tubular aluminum with nylon webbing
& aluminum floor panels. An armrest was mounted between the seats, & each
seat had adjustable footrests & a velcro seatbelt. A large mesh dish antenna
was mounted on a mast on the front center of the rover. The suspension consisted
of a double horizontal wishbone with upper & lower torsion bars & a damper
unit between the chassis & upper wishbone. Fully loaded the LRV had a ground
clearance of 14 inches.
Wheels & power
The wheels consisted
of a spun aluminum hub & an 32 inches diameter, 9 inch wide tire made of zinc
coated woven .033 inch diameter steel strands attached to the rim & discs
of formed aluminum. Titanium chevrons covered 50% of the contact area to provide
traction. Inside the tire was a 25.5 inch diameter bump stop frame to protect
the hub. Dust guards were mounted above the wheels. Each wheel had its own electric
drive, a DC series wound 0.25 hp motor capable of 10,000 rpm, attached to the
wheel via an 80:1 harmonic drive, & a mechanical brake unit. Maneuvering capability
was provided through the use of front & rear steering motors. Each series
wound DC steering motor was capable of 0.1 hp. Both sets of wheels would turn
in opposite directions, giving a steering radius of 10 feet, or could be decoupled
so only one set would be used for steering. They could also free-wheel in case
of drive failure. Power was provided by two 36-volt silver-zinc potassium hydroxide
non-rechargeable batteries with a capacity of 121 A·h. These were used
to power the drive & steering motors & also a 36 volt utility outlet mounted
on front of the LRV to power the communications relay unit or the TV camera.
Control & navigation
Lunar Rover diagram. (NASA)A T-shaped hand controller
situated between the two seats controlled the four drive motors, two steering
motors & brakes. Moving the stick forward powered the LRV forward, left &
right turned the vehicle left or right, pulling backwards activated the brakes.
Activating a switch on the handle before pulling back would put the LRV into reverse.
Pulling the handle all the way back activated a parking brake. The control &
display modules were situated in front of the handle & gave information on
the speed, heading, pitch, & power & temperature levels.
Navigation was based on continuously recording direction & distance through use of a directional gyro & odometer & inputting this data to a computer which would keep track of the overall direction & distance back to the LM. There was also a Sun-shadow device which could give a manual heading based on the direction of the Sun, using the fact that the Sun moved very slowly in the sky.
Deployment
Deployment of the LRV from the LM quad 1 by the astronauts was achieved
with a system of pulleys & braked reels using ropes & cloth tapes. The
rover was folded & stored in quad 1 with the underside of the chassis facing
out. One astronaut would climb the egress ladder on the LM & release the rover,
which would then be slowly tilted out by the second astronaut on the ground through
the use of reels & tapes. As the rover was let down from the bay most of the
deployment was automatic. The rear wheels folded out & locked in place &
when they touched the ground the front of the rover could be unfolded, the wheels
deployed, & the entire frame let down to the surface by pulleys.
The rover components locked into place upon opening. Cabling, pins, & tripods would then be removed & the seats & footrests raised. After switching on all the electronics the vehicle was ready to back away from the LM
Here are many great space sites
An Index with links to almost all our sites.
A Picture of Jupiter, & a Picture of Florida from Space
A Top picture of a Space Shuttle taking off A Top picture of Stars A Nebula
SOLAR SYSTEM RECORD BREAKERS, facts like the tallest mountain for the planets
A site saying the 10 most famous aliens ever
A Clock saying how many people have landed on each planet in our Solar System
Jokes to say to aliens that are offending you
Joke names for aliens, our worst Space site
A List of space associated TV programmes & Movies
http://www.lonympics.co.uk/Olympus Mons.htm Tallest mountain, & volcano in the solar system, & Mars.
A Picture of Buzz Aldrin on the Moon
What would happen if Marsians invaded
A Multiple Choice Quiz on Space
The Moon Deimos The Moon Phobos
Some interesting facts about Space
How Many people have landed on each of our Planets see, in this space clock
A list of Planets that could be colonised by humanity
Some plans for colonising Venus
Jupiter
- the facts
The Moon - the facts
A Quiz on space related TV & movies
The
facts on Space Stations Jodrell
Bank the facts
Ganymede
the facts The Facts on the
Moon Europa
Asteroids
- the facts The Kuiper
Belt - the facts
The
Planet Pluto - the facts Space
- the facts
The Milky
Way - the facts Star Trek -
the facts
The Solar System - just the facts
The
facts on the first Extra Solar planet to be known about by Humans PSR B1257 +
12, the first planet known, of outside our Solar System,
The
Galaxy andromeda The Star
Eta Carinae
Extrasolar
plantes the facts
The
Planet Mercury - the facts
The
Planet Neptune - the facts
The
Planet Uranus - the facts
More
records & amazing facts to do with the Solar System, & space & the Universe
Some ideas for stories, & movie ideas I have had, including some on space
One
of our sites on space in French The
same site in Spanish
A 1 move snippet game, a game where you are 1 space nation fighting another. in Space armageddon
The Entrance to the INTERNET SAFARI, with real animals, most of us had never seen before.
Global Geography, sites like what are the 10 largest English speaking countries, 10 largest Celtic cities, biggest forests, volcanoes,
SOLAR SYSTEM RECORD BREAKERS, facts like the tallest mountain for the planets
Which are the 10 most powerful countries in 2008___
10 Biggest Banks Histories Famous Gates Famous Walls Quizzes Famous Roads Internet Sea Safari, The Most Powerful Countries Ever