The second human Moon landing might have ended in disaster 36 seconds after liftoff. It was 14 November 1969 and the mighty Saturn 5 rocket carrying the crew of Apollo 12 was steadily ascending into the Florida sky when it was hit by lightning.
The mission’s commander, Charles “Pete” Conrad Jr (1930-99) saw a bright flash of light and felt his spacecraft tremble, as though it was flinching from an assault. Alarms rang and every warning light on the boards lit up. Then the Apollo spacecraft’s computer shut down and electrical power to the Command Module (CM) was interrupted. Suddenly the astronauts were plunged into darkness. Coolly, Conrad ignored the Abort handle which would hopefully blast the CM clear of the Saturn. The giant rocket was continuing to rise, so Conrad was going to hold off aborting the flight until he was sure of how bad the situation was.
Things suddenly got worse. Sixteen seconds later, proving an old saying wrong, a second bolt of lightning struck the spacecraft. Meanwhile someone at Mission Control was babbling the cryptic phrase “Try SCE to Aux” into the astronauts’ headsets, Conrad and the Command Module Pilot (CMP), Dick Gordon (b 1929), scanning dozens of instruments to gauge how bad a mess they were in had not a clue what this was all about. Luckily, the third crewman, Alan Bean (b 1932), the Lunar Module Pilot (LMP), remembered this was the procedure to reconnect the spacecraft’s fuel cells, doing this would wake up the concussed computer. He saved the day by punching in the instruction and the computer, vital to the mission, slowly rebooted. One by one, without a fuss, the warning lights went out. Conrad, Gordon and Bean, all US Navy officers, cracked jokes all the rest of the way into orbit.
It is worth remembering the flight controller who also saved the mission by determining the procedure to restart the Apollo’s electrics. His name was John Aaron and he was just 24 years old at the time.
The check out procedures in parking orbit suggested that the vehicle was in good shape despite its ordeal, so the Saturn S-IVB stage fired boosting the mission moonwards. (After the Lunar Module separated from this stage, the S-IVB should have been allowed to sail on in permanent orbit about the Sun. A minor error meant this did not happen as planned and in 2002 amateur astronomer Bill Yeung rediscovered this relic of Apollo orbiting the Earth). On 19 November 1969 Conrad and Bean left Gordon alone in lunar orbit on the CSM Yankee Clipper and descended in the Lunar Module Intrepid to their destination. This was Oceanus Procellarum (the Ocean of Storms, the only “ocean” on the Moon), largest of all the lunar maria or seas. Like Apollo 11‘s landing site, this was a location picked as it was relatively flat and unobstructed rather than for its scientific interest.
Three months earlier Armstrong and Aldrin’s dialogue as they flew to Tranquility Base had been terse and matter-of-fact. In contrast, Conrad, who was renowned as a comedian, kept up a stream of banter as he brought Intrepid down to the barren plain. Neither had he a solemn saying prepared for his first footsteps another world. Jumping off the LM’s ladder he announced “Whoopie!” adding “Man, that may have been a small one for Neil, but that’s a long one for me!” Bean joined him and the exploration began.
Despite a series of navigational problems throughout the mission (unrelated to the lightning strike), Intrepid was just 800 ft ( 244m) from the planned landing site. A mere 400 ft (122m) away stood Surveyor 3, a probe which had landed there two and a half years earlier. Amazingly Gordon, orbiting 69 miles above the lunar surface in Yankee Clipper, was able to see both Intrepid and the Surveyor through the telescope on the LM’s sextant.
Laden with an awkward tool carriers stuffed with hammers, tongs, scoops and other paraphernalia, Conrad and Bean made two EVAs (moonwalks) of about four hours each. One of their first tasks on the first EVA was a failure , as they deployed a colour TV camera on its tripod it was accidentally damaged when Bean pointed it directly at the Sun. There was no live broadcasts in colour from the Moon for the audience on Earth. Some claim this disappointment started the public’s loss of enthusiasm for the Apollo project. The two men succeeded in setting up their ASLEP, a nuclear-powered bundle of scientific instruments including a seismometer, some 450 ft (137m) from the LM before trekking another 600ft to the rim of Middle Crescent Crater.
There was a twelve hour rest break between EVAs, in which the astronauts managed a few hours of fitful sleep hanging in their hammocks. The cabin was too cold and noisy for a decent sleep. On their second EVA the explorers walked considerably further across the dark grey plain, inspecting Head, Bench and Sharp craters before descending on the Surveyor probe which rested in a large crater later named Surveyor Crater. They removed components from the now moribund probe to carry home so scientists could see the effects of the lunar environment on equipment left there for long times (this would be helpful for the design of gear for the Moon bases that would surely be established in the 1970s and ‘80s). Conrad and Bean collected numerous samples of lunar material totaling 75 lb (34 kg), including ejecta from the titanic impact which created the great crater Copernicus, and took many stunning photographs before returning to Intrepid for the last time. Some of these images may have been lost to posterity; a roll of possibly exposed film was mistakenly left behind on the Moon, awaiting collection by some future explorer.
On Apollo missions it was actually the Commander who piloted the Lunar Module, while the LMP acted more as a co-pilot and navigator. However, before Intrepid’s ascent stage rendezvoused with the CSM, while behind the Moon and thus out of contact with Earth, Conrad allowed Bean to take control of the craft. The engineers at Grumman had done a fine job; the little spacecraft flew splendidly, being one of those flying machines, like the Spitfire, that handled as though it were an extension of the pilot’s own body. Bean enjoyed putting the craft through its paces and is still grateful today for his commander’s breach of regulations.
After rejoining Gordon, Intrepid’s ascent stage was abandoned and Yankee Clipper set sail for its homeworld. Meanwhile, Intrepid’s ascent stage was commanded to crash on the Moon about 10 km from Apollo 12’s landing site. This was to calibrate the ALSEP seismometer by letting it read the impact of an object of known speed and mass, the bang was calculated to equal that of one ton of TNT exploding. Although planned to impact about six miles (10 km) from the ALSEP, this Rods from God attack was off-target by about 40 miles (64 km). The length and severity of the seismic disturbance set up by the impact surprised seismologists, who heard strong signals lasting for more than a half hour after the impact and weaker signals which persisted for about an hour after the crash. The following year Apollo 13’s SIVB upper rocket stage crashed into the Moon and the seismometer left there by the Apollo 12 crew picked up vibrations for more than 10 minutes. A NASA press release at the time describing this result quoted Clive Neal, an associate professor at University of Notre Dame as saying “the moon rung like a bell”. Cynical cult leaders, pseudoscientific authors and their sheepish followers have ever since claimed this memorable phrase proves the Moon is hollow and therefore a manufactured object.
On their voyage home, the three men of Apollo 12 were the first to see the Earth eclipsing the Sun. The CM splashed down in the Pacific Ocean on 24 November. In an unlikely accident, the last of an eventful trip, Bean was knocked unconscious when a camera fell at the moment of touch down, striking him on the head and leaving a wound which required stitches , but he suffered no lasting effects. The crew were collected by helicopter and taken to the veteran aircraft carrier USS Hornet.
Two of the crew believed that they would return the Moon. Conrad was a candidate to command Apollo 20 and Richard Gordon was selected to lead Apollo 18, while Bean planned to stick around for the Mars missions. As it was, Gordon never flew in space again, retiring from NASA for a career in business. Conrad commanded the first manned Skylab mission before joining the McDonnell Douglas aerospace corporation. After retiring he was killed in a motorcycle accident. Al Bean had once thought he would get to walk on Mars, but his final spaceflight was as part of the second crew of Skylab in 1973. Garments made for him to wear on the orbital outpost were displayed at Armagh Planetarium in the mid-70s. Since his retirement he has become well-known as an artist, painting scenes of lunar exploration. Forty two years later, NASA’s Lunar Reconnaissance Orbiter imaged Apollo 12’s landing site from lunar orbit. The two sailors’ footprints were still there, enabling us to retrace their perambulations.
Overshadowed by the triumph of Apollo 11, Apollo 12 is unjustly unremembered today. Yet it was a hugely successful mission which showed that despite adversity NASA could reliably send people to the Moon and back and to carry out science on another world. The stage was set for an epic programme of discovery. The next mission would be Apollo 13. Surely it would go more smoothly than its preceding mission.
(Article by Colin Johnston, Science Education Director. A shorter version of this article was published in Astronotes November 2009)