Keeping time on the moon...

Like any decent rocket launch, it started with a countdown. After a short technical hiccup, the crew of Apollo 17 - stuffed into a tiny capsule atop the gleaming white spire of a Saturn V rocket - would be blasted into the infinite stretches of outer space. Until then, time would be measured in those familiar chunks of minutes and seconds, before the giant engines hurled them away from the planet, leaving a long orange streak across the night sky. In just a few days, Captain Gene Cernan would be driving on the Moon. Now, he was staring at his wrist, watching the hands of his Omega creep around with unbearable slowness. Three, two, one...

Words: Dan Read

Photos: NASA

Lift-off. It was 12:33am on 7 December 1972, and as the world fell away behind him, Captain Cernan rolled his spaceship through the upper atmosphere before peeling off towards the Moon. For the next four days, he and his crew would float towards their destination at 3,000mph, except for one bit where they'd hit an invisible speed bump, as Earth's gravity lost its grip and they were grabbed by the Moon's. They would flit between moments of flurried activity and the monotony of a mostly empty universe. All the while, their off-the-shelf Speedmasters would be locked onto Houston time, giving them a sense of constant reality on this cosmic trip.

"Keeping track of time was always a necessity, as well as a way of keeping track of what was going on back home," Cernan tells us. This took on even more meaning when he landed in the silvery valley of Taurus-Littrow. There he was, looking up at a thick, black sky yet blinking in bright sunshine, all the while standing on mankind's own celestial clock, used to measure time for centuries before any watch came along. "In space, time does take on a whole new perspective," he says. "You can make it what you want it to be. However, when you look back at the Earth, you revert to time's relationship with sunrises and sunsets as the world turns."

Four hours after he'd scooted his Challenger landing module around the high peaks of the Taurus mountains, Cernan was ready to make his first bootprints in the sticky Moon dust and, most importantly, to unload his car. His watch - wrapped around the arm of his bulky spacesuit on a long fabric strap - was showing 6pm Houston time, though it was actually early in the lunar morning. With the blue Earth hanging above him, he unstrapped the Rover from the side of the module and folded it into shape. "I jumped up and sideways into the driver's seat as a teenager might hop into an open Jeep, turned on the batteries, tried the steering and goosed it," he later wrote in his autobiography. "The electric motors on each wheel hummed. A Moonmobile with wire wheels and no top is pretty cool."

Already 40 minutes behind schedule, he had to cut short his test drive. There was much Moon farming to be done over the next few days, as they gathered 220 pounds of rocks and samples for the geologists back home. Best to get some sleep first. But unlike his co-pilot, Harrison ‘Jack' Schmitt, Cernan wasn't a scientist. He was a Navy fighter pilot, and an occasionally crashy one at that. So wasn't he tempted just to keep on driving, ripping up the grey dust in a sort of alien grand prix? "Had we been able to stay outside the LEM [Lunar Excursion Module] for longer than the seven to eight hours at a time, we could have," says Cernan. "And we were tempted to ‘drive around the corner' and see what was on the other side of the mountain."

Back inside the tiny module, both men wriggled out of their suits and slouched into their tight hammocks, relaxing in their liquid-cooled underpants while examining Moon rocks. Outside, during their first extraterrestrial walkabout, Cernan said that time had "galloped away". Inside, it almost ground to a halt. And, to make things worse, he was now fixated on the frustratingly slow ticks of two watches: the one he wore under his suit and the one he usually wore outside but had now affixed to his other wrist. "When outside the spacecraft, we never had enough time to do what we needed and wanted to do," he says. "Inside, it seemed like a total waste of time to be resting and not taking advantage to do everything possible during the three days we were on the Moon."

The next morning they were woken by the Ride of the Valkyries, piped over the radio from Houston. Over the next few days, they'd take more drives among the craters and foothills of the towering mountains, making frequent stops to dig and drill. Eventually, they would cover a total of 19 miles - more than any previous mission... just as soon as Mission Control came up with a fix for a broken bumper, which Cernan had caught with the edge of a rock hammer on the first day. With a remedy including folded maps and screw clamps, they patched it up, though the churning wheels still sprayed soil right into the astronauts' visors. Despite this, Cernan managed to break the lunar speed record, at a stellar 8.7mph, while travelling down a steep hill.

It may have been great fun, but every sortie had a golden rule: they could never drive further than the distance they could walk back to the module. In such a weird place, measuring time and distance wasn't just useful: it was essential, and his Speedmaster was a life-support machine. It's no wonder Cernan says the watch was one of his most valued parts of the mission, not least because they weren't allowed any sort of personal trinkets up there. He still has it today, one of the few bits of Moon memorabilia the astronauts were allowed to keep, along with his mission patch and a rogue Playboy centrefold that mysteriously found its way into the pages of his flight plan.

On the final day, before setting off for home, there was just time for one last drive. Cernan jumped into the Rover and sped off through the boulder field, parking it a mile away from the module so its video camera could record their lunar take-off. In one-sixth gravity he bounced back to the module in playful slow-mo, climbed the steps and struggled out of his hefty Moonwear. After a final glance at his watch, and as Mission Control began another countdown, Cernan took the controls and turned to his co-pilot.

"OK, Jack," he said. "Let's get this mutha outta here."