Apollo 15 was sent to the Moon in July 1971, its primary mission goals to explore the spectacular Hadley-Appenine region, carry out scientific experiments from orbit and evaluation of new and improved Apollo equipment,including the Lunar Rover. Here is the story of  possibly the most ambitious Apollo moon landing.

Image of Apollo 15 crew

Scott, Worden and Irwin (Image credit: NASA)

 

The next time you see the full Moon high in the south, look carefully at the centre of the northern part of the Moon’s near side. About a quarter of the way down the disc are the two blotches of the Mare Imbrium and Mare Serinitatis. Between them is a mountain range, Montes Apenninus, named after the Apennine Mountains in Italy. In this lunar mountain range lies the 4.6 km peak of Mt Hadley. It was at the plain below Hadley that three men from the planet Earth landed in July 1971, their mission to make one of the greatest scientific explorations ever. This was Apollo 15.

 

Image of A15 landing site_map

Apollo 15’s landing site, note Hadley Rille in the photograph and craters named for a couple of classic SF novels. (Image credit; NASA)

 

 

Apollo 15 was launched moonward from Kennedy Space Center on 26 July 1971 (the day my brother was born!) on a Saturn V rocket. Compared to the Saturn used by the previous Apollo missions, this one was upgraded to send a heavier payload to lunar orbit.  Squeezed into the Command Module Endeavour was Commander David R. Scott (1932- ), Lunar Module pilot James B. Irwin (1930-91) and  Command Module Pilot Alfred M. Worden(1932- ). Scott was a veteran of Gemini 8 and Apollo 9, but his crewmates were both entering space for the first time.

 

Image of apollo_15_subsat

Apollo 15 deploying its subsat in a pre-flight artist’s impression. (Image credit: NASA)

 

This was the first of the “J-series” Apollo landings (and thanks to cuts to NASA’s budget there would be only three of these), designed for a longer stay and to enable a rigorous scientific investigation of the landing site. It was just two years since Apollo 11, but the technology was enormously improved. Apollo 15’s Lunar Module Falcon carried an improved engine and larger fuel load, enabling more equipment and supplies to be carried plus a longer hovering time to allow its crew to make a pinpoint landing. Among its cargo was a Lunar Roving Vehicle (LRV), a 4-wheel drive electric car created by Boeing to widen the terrain visited by the astronauts. The astronauts themselves wore A7L spacesuits, enhanced and made more comfortable (essential for longer EVAs) on the basis of experience from previous missions. Importantly, they were easier to take off and put on. J Series crews could strip down to their longjohns to sleep in hammocks stretched across the LM’s cabin.

 

image of Apollo 16 CSM

The Command Service Module Endeavour in orbit around the Moon. (Image credit: NASA)

 

The Command Service Module, home to Worden while his colleagues explored the surface, was a newer and better model too. A panel could be jettisoned from the drum-shaped Service Module to reveal the SIMBAY, a battery of instruments including a deployable subsatellite to map the Moon’s gravitational field and a powerful survey camera to make detailed images of the Moon’s battered peaks and plains.

 

Image from SEVA

A panorama assembled from images taken by David Scott during his “stand up EVA”. The view is to Falcon’s rear, note the VHF antenna and the subtleties to the tones of the lunar surface. (Image credit NASA)

 

NASA’s army of technicians was by now making it look very easy send people across deep space to land on another world. Everything went smoothly, too smoothly perhaps as the mission provoked very little interest from the general public;  perhaps NASA should have played up the drama.  Laden with tools and scientific gear, the Lunar Module Falcon swooped low over the Apennines before descending vertically to touch down near Hadley Rille on 30 July 1971. To be exact, the craft sat at a pronounced tilt 600 m from the planned landing site in a region of the Mare Imbrium called Palus Putredinus, the unattractively named Marsh of Decay. Scott and Irwin found the terrain in the area to be cratered and rolling with a towering backdrop of nearby mountains (Scott took several unique panoramic images by standing on the LM’s Ascent Engine housing and poking his head and shoulders through the docking hatch on Falcon’s roof). The Apennine Mountains, envisioned as steep and jagged, turned out to be gently rounded by nearly four billion years of micrometeoroid impacts. These mountains were why this place had been selected as a landing site. They were suspected to be composed of ancient primordial rock unchanged from the Moon’s then mysterious birth, samples of their material ought to litter the lava plain to provide clues to the Moon’s origin. Another attraction was Hadley Rille, a deep and sinuous channel 450 m deep which wriggled for hundreds of kilometres across the plain.

 

Image of Hadley base

Falcon listing to the side and James Irwin tending to the LRV with Mt. Hadley in the background. The pile of foil marks where the LRV was unpacked. (Image credit: NASA)

 

Shortly after setting foot on the parched grey dust, Scott and Irwin unpacked the folded LRV from its nook in Falcon‘s descent stage. They pulled on two lanyards which released the Rover and let it swing down on its hinges. As it did, it began to unfold.  Minutes later it was resting on its wire mesh tyres  and ready to go. Scott had the honour of the first test drive, soon he and Irwin were bouncing along towards Hadley Rille at 7mph. (The LRV was not the first wheeled vehicle to roll across the regolith, Lunokhod 1,  a Soviet robot was wandering over the Mare Imbrium at that very minute and had been there since the previous December).  In the next three days Scott and Irwin made three moonwalks accumulating 18 hours, 35 minutes outside the LM and drove 28 km. After the final EVA Scott performed a famous demonstration of a hammer and feather falling at the same rate in the lunar vacuum. The CSM remained in orbit overhead while Worden performed scientific experiments.

 

Image of Apollo_15_LM_station_6

The LRV allowed the astronauts to leave the LM far behind. (Image credit: NASA)

 

 

 

Apollo 15’s crew, all former military airmen, took their role as scientists very seriously to the delight of geologists (a previous Apollo crew had disgruntled the scientists on the ground by taking a flippant attitude to collecting samples, but in contrast Scott and his crew had become genuine rockhounds). Thanks to the astronauts’ skills and enthusiasm, their new gear and the location, this was a hugely productive mission. Perhaps the most important sample found was the “Genesis Rock”, a lump of white crystalline anorthosite, possibly a piece of the Moon’s primordial crust. Apart from meteorites, this is the oldest object in human hands, dated at 4.5 billion years old, only 100 million years younger than the Solar System.

 

Image of David Scott on Moon

David Scott with the Appenines in the distance (Image credit: NASA)

 

 

 

The LM lifted off from the Moon on 2 August after nearly 67 hours on the lunar surface, during this time the astronauts had covered 27.9 km in the LRV, driving right the edge of Hadley Rille. They collected 77 kg of rock and soil samples, treasures more valuable than gold. After rejoining Worden, Endeavour set off towards its homeworld. On 5 August, between the Moon and Earth, Worden carried out the first deep space EVA when he exited the CM and made three trips to the instrument bay at the rear of the SM to retrieve film canisters.

 

Image of Al_Worden_during_EVA

All alone in the night: Al Worden at work between worlds. (Image credit: NASA)

 

There was a scary moment during the final minutes of the voyage. During descent, one of the three main parachutes failed to open fully, and the CM splashed heavily in the rolling waves of the Pacific Ocean 330 miles north of Honolulu, Hawaii, alarming but not injuring the crew. It was 7 August 1971. After this heroic homecoming, the three astronauts suffered a sudden fall from grace when their management discovered that Apollo 15’s crew had carried postal stamps to the Moon for resale at high prices to collectors. All three were disciplined and never flew in space again. Worden and Scott took desk jobs with NASA for a few years, while Irwin left the agency to become a preacher, involving himself in several quixotic quests to locate Noah’s Ark. Worden and Irwin both visited Armagh Planetarium in the 1970s.

Apollo 15 was in many ways the perfect Apollo mission, the men and their machines did everything that was expected of them. Those were great days!

(Article by Colin Johnston, Science Education Director)


15 Comments

semaj · November 16, 2016 at 14:52

Any one found the tyre tracks yet??????

    admin · November 16, 2016 at 16:03

    Dear Semaj, please see a higher resolution version of the image for all the tyre tracks you could want. You might want also to see some the images taken before and after too, at https://www.hq.nasa.gov/alsj/a15/a15.html .

semaj · March 4, 2016 at 11:51

Lucky that US flag was perfectly lit again in shadow, not that there would be anybody to see it on the moon!
I would still like to know where are the tyre tracks and footprints in ‘the LEM far behind’.

semaj · February 6, 2016 at 20:26

Sorry should have said picture partly titled.

semaj · February 6, 2016 at 20:25

The picture partly titled leaving the LEM far behind, where are the tyre tracks and footprints? Oops!

John Spade · December 23, 2015 at 18:27

I was assigned TAD aboard tha USS Okinawa for the Apollo 15 recovery. This was the best experience of my time in the Navy as most of it was spent doing Westpac tours to Vietnam. During the recovery they sold memorabilia of the event. I have jacket patch, ball cap patch, a menu of the ship’s splashdown dinner and some decals. They are all in amazing condition after all these years of storage. My problem is that all my personal pictures I took of the capsule inside the hanger deck and photos of the astronauts were destroyed during a hurricane last year. I decided to make a display of these items to pass on to my heirs. I’m looking to replace those photos so I can complete my display. Any help would be greatly appreciated. Thanks….Happy Holidays….John

ileavazan · May 20, 2015 at 11:49

Home alone in the night: Al Worden at work between the two worlds – studio set and virtual reality .

    admin · May 20, 2015 at 12:43

    Dear Ileavazan, no, in this caption (a kind of shout-out to the opening narration of the old Babylon 5 TV series) I meant the Earth and Moon. Sorry if I was unclear.

Gerardine Burns · September 17, 2011 at 20:46

I had the pleasure of meeting Al Worden in Glasgow in May of this year. It was wonderful to hear first hand Al describing how during his EVA he had full view of both the earth and the moon at the same time.

    admin · September 19, 2011 at 09:00

    Lucky you, wish I had been there!

Andrew W · August 14, 2011 at 05:02

Thanks for that Colin, great post, though reading it brings home the disappointment of the forty lost years.

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