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Apollo-17: The last men on the Moon

Anatoly Zak, Spaceflight Correspondent
May 14, 2016, 15:19 UTC

Sen—With three final missions slashed from the NASA budget, Apollo-17 became the final lunar landing of the Apollo program.

Like the two previous flights, Apollo-17 used the J-series spacecraft enabling longer stays on the surface of the Moon, greatly enhanced by an addition of the lunar rover. The Challenger lunar module could support astronauts on the Moon for 75 hours with an additional 12 hours for an emergency.

The crew consisted of the commander Eugene Cernan, who three and a half years earlier had flown just a few kilometers from the Moon during the Apollo-10 mission; the command module pilot Ronald Evans and lunar module pilot Harrison Schmitt. The lunar rock expert, Schmitt became the first and only professional geologist making a trip to the Moon during the Apollo program.

The Apollo-17 expedition headed to a narrow valley known as Taurus-Littrow squeezed near the coast of a huge "sea" of Serenitatis made of frozen basalt. Schmitt later wrote that "it would have been hard to find a better locality in which to synthesize and expand our ideas about the evolution of the Moon."

The 12th Saturn-5 rocket blasted off from Pad 39A at Cape Canaveral, Florida, on Dec. 7, 1972, at 00:33 local time. The liftoff came two hours 40 minutes late because of a problem with the pressurization of the oxidizer tank on the rocket's third stage. It was the only night launch of the Apollo program, dictated by the orbital mechanics of the reaching the required landing site. The Saturn-5 rocket was topped with the America command and service module and the Challenger lunar module.

The discarded third stage of the Saturn was aimed directly into the Moon and on December 10, it crashed near the Far Mauro crater sending a shockwave which was registered by seismic sensors left by crews of Apollo-12, Apollo-14, Apollo-15 and Apollo-16.

After 12 orbits around the Moon, the Challenger lunar module with Cernan and Schmitt separated from the America command and service module piloted by Evans.

On December 11, at 19:54:57 UTC, the Challenger made an almost picture-perfect landing just 250 meters away from the target.

The crew began its first spacewalk with the unloading of their rover and the installation of scientific instruments. The two astronauts succeeded with drilling the lunar surface all the way to 2.5 meters to install scientific sensors. They also made a 3.3-kilometer car trip southeast toward the Steno crater, across heavily cratered surface in search of good geological specimens, which would total 14.3 kilograms. The first spacewalk lasted seven hours 12 minutes.

During the second excursion, the first order of business was to install an improvised extension on the flap of the rover wheel, which was damaged a day before. Otherwise, the astronauts and their  instruments were constantly showered with a thick rain of omni-present lunar dust.

Then Cernan and Schmitt embarked on the longest trip of the expedition lasting more than an hour and extending 7.4 kilometers southwest from the Challenger. Near the Shorty Crater, they found a strange orange-colored soil. The location yielded a really unique geological finding—tiny beads of orange volcanic glass. As was later shown, it was produced by erupting fire fountains from the depths of up to 200 miles more than 3.5 billion years ago! 

The pair covered a total of 20.4 kilometers during their drive. It was also the longest moon walk lasting seven hours 36 minutes and 56 seconds. A total of 34.1 kilograms of samples were brought onboard the lunar module that time.

During the third and final lunar walk the astronauts headed north. By the end of the 12.1-kilometer trip, they already noticed that their gloves had been damaged by the abrasive effect of the lunar dust.

At the conclusion of the seven-hour, 15-minute spacewalk, they parked their rover 150 meters away from the Challenger with its camera pointed at the Apollo's final departure from the Moon.

In three spacewalks, Cernan and Schmitt covered 35.7 kilometers and gathered 110.5 kilograms of precious lunar samples. They logged 74 hours 59 minutes 40 seconds on the surface.

The ascent module of the Challenger blasted off from the Moon on December 14 at 22:54 UTC. It docked with the America command and service module after two failed attempts. The reunited crew spent two more days in lunar orbit and departed back to Earth on December 16. 

During the traverse between the Moon and the Earth, Evans ventured from the command module to the service module on the exterior of the spacecraft to retrieve exposed film.

The command module made a successful splashdown on Dec. 19, 1971, at 19:24:59 UTC in the Pacific Ocean. The mission of Apollo-17 lasted 12 days 13 hours 51 minutes and 59 seconds.

With the landing of Apollo-17, the biggest adventure of manned space flight was over. At the time, the participants of the Apollo program could hardly imagine that until the end of the century, humans would not return to the Moon or even venture beyond low Earth orbit.