Apollo 16’s cliff‑hanger

On 16 April 1972 Apollo 16 launched, the first expedition to land among the lunar mountains. The crew were John Young, Ken Mattingly and Charles Duke. When they reached the moon and went into orbit, Mattingly told Houston, “It feels like we’re clipping the tops of the trees.” Duke described:

“It did feel like we were right down in the valleys. I couldn’t believe how close we were to the surface… we were rocketing across the surface at about three thousand miles per hour in this low orbit, with mountains and valleys whizzing by. The mountain peaks went by so fast, it gave you the same impression as looking out your car window at fence posts while travelling at seventy miles per hour.”

Young and Duke climbed into the lunar module, while Mattingly stayed in the CSM which they had named Casper. Just after they separated, the CSM was scheduled to make a burn to change orbit but when Mattingly turned the engine on, he reported:

“There is something wrong with the secondary control system in the engine. When I turn it on, it feels as though it is shaking the spacecraft to pieces.”

This was serious – that engine was their ride home! Young thought hard and though he hated to say it, ordered, “Don’t make the burn. We will delay that manoeuvre.”

Their hearts sank down to their boots – two and a half years of training and only 12.9 kilometres from their target and now it looked like they would have to abort and return back to Earth. The two spacecraft circled the Moon in company, anxiously waiting for an answer from Houston.

Duke recalls, “We knew in our minds it was very grim. It looked as if we had two chances to land – slim and none. We were dejected.”

“It was a cliff‑hanger of a mission from where we were sittin’ in the cockpit,” Young said. “The secondary vector control system on the SPS motor wasn’t workin’ right and if they didn’t work right the mission rules said it was no go. The people on the ground did studies at MIT and Rockwell and in the end it worked out just fine.”

Houston advised them that it would be okay even if they had to use the back‑up engine controls.

The mission was equipped with a lunar rover vehicle which set a lunar speed record of over 17 kph. Lindsay:

Back at the Lunar Module after the first excursion, Young put the rover through its paces in front of the movie camera. Duke described the scene: “He’s got about two wheels on the ground. It’s a big rooster tail out of all four wheels and as he turns, he skids the back end, breaks loose just like on snow. Come on back, John… I’ve never seen a driver like this. Hey, when he hits the craters it starts bouncing. That’s when he gets his rooster tail. He makes sharp turns. Hey, that was a good stop. Those wheels just locked.”

Young explains, “We drove it to see how it worked. We had to go up the side of a mountain with slopes more than 200, and I think we did that because we bottomed out the pitch meter. We wanted to see how the vehicle handled. We had the camera there to document it too, which nobody else had done before. It was like driving on ice when you cut the thing too sharp at about 5 or 7 kilometres per hour, it would slide out and go backwards. The stuff on the Moon is very slippery. You don’t hear anything but your suit pumps going when you’re drivin’ in a vacuum. It was very difficult to get in and out of – the Apollo 17 guys had a scoop to pick up rocks without even stopping the rover.”