Moon car

The lunar car significantly expanded the lunar surface available to astronauts . Previously, astronauts could only move on the moon on foot and, therefore, only directly around the landing site due to the spacesuits and other life support equipment that bound them. On a lunar rover, astronauts could move along the moon at a speed of up to 13 km / h. During the expedition "Apollon-16" a record was set for the speed of movement on the moon - 18 km / h. The total length of the path traveled by lunar cars on the expeditions Apollo 15, Apollo 16 and Apollon 17, was 28, 27 and 36 km, respectively ^[1] .

Lunar car wheel

Lunar Car Dashboard

The lunar vehicle was equipped with four Delco DC TEDs (each mooncar wheel was driven by an individual TED ) with a power of 190 W each at revolutions of up to 10 thousand rpm. Torque transmission was carried out through a 80: 1 reduction wave reduction gear , as well as by two steering engines (one for the front and rear wheels). The source of electricity is two non-rechargeable silver-zinc batteries with a voltage of 36 volts and a capacity of 121 Ah each. The design provided for the possibility of power from the batteries of an electric vehicle, a communication device or a television camera. The batteries and electronics were equipped with a passive cooling system.

The wheels of the moon car were developed by General Motors . The design of the wheel included an aluminum disc and a tire with a diameter of 810 mm and a width of 230 mm. The tire was made of braided steel wire (fibers) 0.84 mm thick with zinc coating. About 50% of the tire area was occupied by a special titanium tread for reliable contact with the ground. Above the wheels were dust shields.

The lunar vehicle had a mass of 210 kg and a payload of 490 kg under lunar gravity. The chassis frame 3 m long with a wheelbase of 2.3 m was welded from aluminum pipes (aluminum alloy 2219).

The frame consisted of three parts, hinged together, due to which it was folded and during the flight to the moon was fixed outside, in compartment 3 of the landing stage when folded, occupying a volume of 0.85 m ³ . The car was lowered to the ground by two astronauts using a block-cable system, the chassis and seats were laid out and fixed ^{[2] [3]} .

A directional antenna was stored in another compartment. The maximum height of the car was 1.1 m. Ground clearance at full load - 350 mm. The turning radius is about three meters ^[4] .

The machine was controlled by a T-shaped handle located between the seats:

• handle feed forward - forward movement (backward - in reverse mode);
• left-right - rotation, respectively, left or right;
• backward - braking;
• completely back - parking brake.

On the handle there was a switch of the direction of travel (forward / reverse). Instrumentation equipment was mounted on a separate panel and included the following instruments: speedometer , distance indicator, bearing (heading), tilt, battery power and temperature indicators.

The speed of movement was about 8-10 km / h, although in some areas the moonmobile could accelerate to 16 km / h and even setting a record of 18 km / h, which, however, created only problems, since gravity on the Moon at 6 times less than that on Earth, and, despite the full load of the lunar all-terrain vehicle, it was significantly thrown up on uneven ground.

Navigation was provided by a gyrocompass and an odometer . In addition, a simple device was mounted on the dashboard to determine the azimuth of movement from the shadow of the gnomon pin . Given the extremely low speed of the Sun in the lunar sky, the accuracy of the device was quite satisfactory.

The lunar car was equipped with its own radio and television communications system. There was a pointed omnidirectional parabolic antenna for direct communication with the Earth, and also an omnidirectional antenna. A color camera and a 16 mm movie camera, as well as a 70 mm camera, were installed on board. For them there was a stock of films in cassettes.

Each lunar car was used for three trips - one on each of the three days of the expedition.

The maximum distance from the lunar car from the lunar module was limited by the resources of individual astronaut support systems, which should have been enough to walk back to the module in the event of a breakdown of the lunar car. After the lunar cars and spacesuits of the astronauts demonstrated their reliability, this restriction was relaxed during the last expedition (Apollon-17), which made it possible to move away from the lunar module to a maximum distance of 7.6 km.

During the operation of the LRV on the moon, astronauts experienced a number of difficulties. So, during the Apollo 16 expedition, the second exit to the ground (place - point No. 8) astronaut Young accidentally touched the dust shield of the moon car and tore it off. The dust raised by the wheels of the mooncar showered the astronauts, the control console and radio communications equipment. The batteries began to heat up, and the power consumption exceeded the standard rate. Repair, however, was not made. The same part was torn off during the Apollo 17 expedition (Eugene Cernan touched it with the handle of a geological hammer). Astronauts fixed it with duct tape, but due to dust the tape did not hold well, and an hour later the shield was completely lost. The moonmobile again showered itself with dust. It was decided to fix the damage on their own. The astronauts made a dust shield from improvised materials using terrain maps, duct tape and clips - fixture detectors taken from the lunar module. Maps with traces of moon dust erosion were returned to Earth and are exhibited at the National Air and Space Museum .

A color television camera mounted on a moonmobile with a 6x zoom lens was equipped with an electric drive for turning in horizontal and vertical planes and changing the focal length, thanks to which it could be controlled not only by astronauts, but also an operator from the Earth. This greatly expanded the possibilities of video filming and, in particular, made it possible to photograph the start of the lunar module from the moon. For such a shooting, the lunomobile was previously left in position at such a distance from the module that all of it fell into the field of view of its television camera. The operator on Earth, focusing on the television picture from the camera, controlled its drive, accompanying the take-off of the module. Although the start time was known to within seconds, due to the noticeably long passage of the signal along the Moon – Earth – Moon chain, the operator had to work with time lead. So, vertical panning had to start when the module was still on the ground on the operator’s telepicture. This made it difficult to shoot, as a result of which the launches of the lunar modules were poorly captured on the Apollo 15 and Apollo 16 expeditions. However, on the Apollo 17 expedition, the start of the lunar module was successfully captured ^[5] .

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  The Falcon (in the background) and the Lunar Rover during assembly at the Kennedy Space Center

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  Moon Rover No. 1 at the Boeing Corporation plant in Kent, Washington , just before it was shipped to the Kennedy Space Center

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  Expedition Apollo 16. John Young is working on a lunar car next to the Orion lunar module. April 1972

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  James Irwin at the Lunar Rover

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  David Scott and the Moon Rover at Hadley Rill Canyon

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  Expedition Apollo 17

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  Expedition Apollo 15. James Irwin next to the lunar car. 1971 year

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  James Irwin is holding the Lunar Rover by the Green Boulder. For calibration, David Scott placed a rake on the boulder

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  Expedition Apollo 17. Eugene Cernan makes a test run on a lunar car

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  Lunar car, Apollo 15 expedition

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  David Scott and James Irwin train on Earth to use the lunar car on Apollo 15

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  Lunar car Apollo 15

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  Apollo 16 commander John Young drives a lunar car

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  Apollo 16 commander John Young on a lunar car

• Lunokhod (space program)
• Planet rover
• Selenohod

• A. Pervushin. The battle for the moon. - Amphora, 2007.
• General Description of the LRV, NASA Website
• Complete technical documentation and LRV instruction manual (NASA website, pdf file, 38 MB, 201 pages )
• Lunar Roving Vehicle . - Houston : Boeing Press Suites, 1972 .-- 24 p.