Lunar expedition

The second moonwalk was a "geology traverse" similar to that carried out on Apollo 12. The astronauts were asked to inspect the 300m-(1,000ft-) high rim of the nearby Cone Crater and found the climb up its outer flanks quite arduous even in one-sixth Earth gravity - especially as they were also towing a lunar cart called the Mobile Equipment Transporter (MET) with them. As they approached the rim, the terrain grew increasingly steep and hilly, and frustratingly they could not find the crater edge itself. After much debate, they turned back, not realizing until later that they had come within about 30m (100ft) of their goal.

On their return to Earth, the astronauts had to endure the same fortnight of quarantine suffered by their earlier colleagues. After they too failed to show any signs of unexpected illness, the practice was discontinued for later missions.

alsep experiments

The astronauts laid out the various ALSEP experiments according to a map carried on their cuff checklists. The box in the centre is a detector for charged porticles from space, while red flags mark geophones used to detect sound waves from the "thumper" experiment.

ANTARES at rest

Ed Mitchell named the LM Antares after the bright star most likely to be visible during the descent from orbit. The module landed on the edge of a depression and came to rest tilted over at an angle of 8°.

HE MO

licks up during I rts to m< 1 probes

1961

Man must explore, and this is exploration at its greatest"

Apollo 15 Commander David Scott, on Hadley Rille

1978

70MM HASSELBLAD CAMERA

Specially modified Hosselblad electric cameras were carried on the chest packs of all the Apollo astronauts. The familiar + marks allowed measurements of distance to be made from the photographs.

DIGGING A TRENCH

James Irwin's work digging a trench in the topsoil was easier than the drilling, but he still hod to stop at a depth of 30cm (1ft).

26 July 1971

Apollo 15, first of the J-dass Apollo missions, launches from Cape Canaveral.

29 July 1971

The spacecraft enters lunar orbit.

30 July 1971

The LM Folcon touches down on target close to Hadley Rille and the Lunar Apennine mountains.

31 July 1971

David Scott and James Irwin make the first of three expeditions onto the lunar surface. The LRV is used on the Moon for the first time.

2 August 1971

After a third moonwalk, Scott and Irwin lift off and return to the CSM in lunar orbit.

4 August 1971

Apollo 15 leaves lunar orbit on the return journey to Earth.

5 August 1971

Al Worden performs the first spacewalk beyond immediate Earth orbit, retrieving film and experimental data from the CSM's instrument bay.

Apollo 15

Apollo 15 was the first of what were known as the J missions - the ultimate development of Apollo as it was initially planned. For these missions, modifications to the CSM (in this case Endeavour) included the addition of a palette of scientific instruments mounted on the Moon-facing side of the hull. These would turn the orbiting module into a powerful science satellite in its own right and give the CSM pilot an expanded role in the mission. The LM, meanwhile, now carried the Lunar Roving Vehicle (LRV) - a Moon car developed by Boeing, which was folded and stored on the side of the module during descent. This massively increased the range over which the astronauts could travel, but improvements to life-support systems also had a role to play, as they allowed a much longer stay on the lunar surface.

Apollo 15's crew was led by Neil Armstrong's Gemini 8 partner David Scott, with James Irwin as LM Pilot and Alfred Worden in the CSM. Apollo 15 blasted off on 26 July 1971 and arrived in lunar orbit without any major problems.

Climbing lunar mountains

The Lunar Module Falcon touched down near a long, winding valley known as Hadley Rille on 30 July, and during almost three days on the Moon, Scott and

Climbing lunar mountains

The Lunar Module Falcon touched down near a long, winding valley known as Hadley Rille on 30 July, and during almost three days on the Moon, Scott and

first wheels on the moon

The LRV is seen here shortly after its first deployment onto the Moon. The tyres were actually made of woven wire mesh with chevron-shaped treads riveted on - making them far more effective shock absorbers.

Back on firm ground after the success of Apollo 14, the next Apollo mission was a major advance, as an improved CSM, a longer stay on the Moon, and the addition of a lunar rover yielded great results.

Irwin undertook three separate moonwalks. The first of these tested the LRV on a trip to the base of Mons Hadley Delta, a mountain in the Lunar Apennine range some 4km (2Vi miles) away. The rover performed well, although Scott had some difficulty getting used to its rear-wheel steering. Travelling at an average of 10kph (6mph), they needed to test the brakes on several occasions when they unexpectedly found themselves on the edge of a crater.

During this expedition, they made two long stops to explore geology around Elbow Crater and at the base of the mountain itself. In preparation for their mission, these astronauts had undergone far more extensive geology field training than their predecessors (including simulated expeditions in the New Mexico desert), and the extra work paid off as the later Apollos generated huge amounts of data that would ultimately allow geologists back on Earth to piece together the Moon's history.

On the second day, the astronauts returned to the same area, but this time they climbed the mountain itself, collecting samples including one that was later nicknamed "the genesis rock" after studies back on Earth revealed that it was more than four billion years old - almost as old as the Moon itself. Back at the LM, the astronauts had also been at work setting up the ALSEP package and conducting other experiments. Drilling into the lunar rocks to collect samples proved far more difficult than expected, and the final LRV expedition had to be shortened - though it still took the astronauts to the edge of Hadley Rille itself.

After their return to the CSM on 2 August, the astronauts spent a further two days in lunar orbit, during which time they continued scientific work and deployed a small satellite into lunar orbit.

first wheels on the moon

The LRV is seen here shortly after its first deployment onto the Moon. The tyres were actually made of woven wire mesh with chevron-shaped treads riveted on - making them far more effective shock absorbers.

navigation sub-system power and temperature monitors

speed indicator

„ high-gain antenna power and temperature monitors hand controller reverse inhibit switch lunar roving vehicle

Built for strength, lightness, and robustness on the rough lunar surface, the LRV's chassis was made of aluminium tubing, and its wheels were of shock-absorbing aluminium wire mesh. Apollo 17's Gene Cernan described the rover as "one of the finest running little machines I've ever had the pleasure to drive".

low-gain antenna

16mm data-acquisition camera pack control console

The LRV was driven with a simple hand controller - pushing forwards increased speed, while turning steered the wheels. Reverse gear was blocked unless a switch on the controller's upright section was pressed.

instrument panel hand controller

mobility test article

Marsholl Space Flight Center at Huntsville led the development of the LRV, building various "test articles" that led to the finished vehicle. Independent motors and steering for each wheel were a vital element of the LRV's final design.

TECHNOLOGY

a car for the moon

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