“We almost completely rebuilt the station between Apollo 14 and Apollo 15, working masses of overtime – so much so that some staff members begged for a break. The difference between 14 and 15 was almost like a new project. There were a whole new lot of communications with scientific experiments in the Service Module, there was a Particle and Fields sub-satellite which was ejected from the Service Module into orbit around the Moon, there was a lunar rover vehicle which they drove around on the surface of the Moon. The communications were becoming horrendous – there were so many links involved – back packs of the astronauts, the relay from the lunar rover, the Lunar Module, the Particle and Fields Satellite… we went into the mission not sure we could handle all this.
“Again we had the lion’s share of that mission – we had all the walks on the surface of the Moon, all the bringing up of the first lunar rover down link to the ground – all the critical parts of that mission we were prime. Although we went into the mission with quite a bit of trepidation, it was quite amazing, it all went by the book – it was perfect. Apollo 15 was the scientific and technical peak of our operation as far as I was concerned.”
Apollo 16’s cliff-hanger
“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.”
“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.
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.”