Friday, April 16, 2021

Apollo 12 meets Surveyor 3 on the moon

© Mark Ollig


NASA’s Surveyor 3 robotic lander touched down on the moon, April 20, 1967, near the edge of a crater in the Oceans of Storms (Oceanus Procellarum).

Communication with Surveyor 3 took place using NASA’s Deep Space Network (DSN) radio-telemetry system.

The DSN is an interconnected global array of giant radio antennas located in California, Spain, and Australia. NASA uses it for communicating with Earth-orbiting and interplanetary spacecraft.

Surveyor 3’s lunar soil surface sampler dug 7 inches into the lunar soil and sent photographs of it back to NASA to determine the soil’s properties, including strength, texture, and structure.

The Hughes Aircraft Company manufactured the Surveyor 3 lunar lander, and its television camera used a Vidicon tube initially developed by RCA back in the 1950s.

The lander was operational on the moon until May 4, 1967, when NASA received its last stream of data.

NASA confirmed Surveyor 3 completed all of its mission objectives.

In all, Surveyor 3 transmitted 6,326 photographs back to Earth.

The Apollo 11 lunar module named Eagle landed on the moon, July 20, 1969, in the Sea of Tranquility.

The Eagle was 950 miles west of Surveyor 3.

Apollo 12 astronauts Charles “Pete” Conrad Jr. and Alan Bean landed their lunar module named Intrepid, Nov. 19, 1969, just 535 feet northwest of Surveyor 3.

Some 60 miles above the moon inside the Apollo 12 command module named Yankee Clipper, astronaut and command module pilot Richard Gordon Jr. was able to see both the Intrepid and Surveyor 3 using a 28-power sextant telescope.

During the Intrepid astronauts’ second lunar extravehicular activity, November 20, astronauts Conrad and Bean walked to the Surveyor 3 landing site.

There, they retrieved parts from the lunar lander, including its 17-pound television camera, because NASA scientists wanted to study the effects of long-term exposure to the moon’s elements on the camera’s gears, motors, optics, metals, and lubricants.

The astronauts collected the camera, motorized soil scoop, television camera cable, and aluminum tubing.

The scientists back on Earth were particularly interested in the cable because of the biological organisms it carried from Earth and wanted to know if any had survived.

Conrad and Bean reported the Surveyor 3 footpad marks were still visible and that the entire spacecraft had a brownish appearance.

The astronauts took many photographs before removing any parts from Surveyor 3 to be brought back to Earth.

Surveyor 3’s television camera is now on display at the Smithsonian National Air and Space Museum in Washington, DC.

It is important to note that about 37 seconds after Apollo 12 lifted off the launch pad from Cape Canaveral, it was struck by lightning, knocking out all of its onboard instrumentation systems and telemetry with Mission Control in Houston, TX.

“What the hell was that?” exclaimed the command module pilot Richard Gordon.

“I just lost the whole platform,” commander Charles Conrad Jr. reported to Mission Control.

“Okay. We just lost the platform, gang. I don’t know what happened here; we had everything in the world drop out,” Conrad said.

Loud voices in Mission Control were trying to figure out what course of action to take.

Mission Flight Controller John Aaron realized the Signal Conditioning Electronics were down.

“Flight try SCE to Aux,” Aaron recommended to Mission Flight Director Gerry Griffin.

Mission Control radioed Apollo 12, “Apollo 12, Houston. Try SCE to Auxiliary. Over.”

“Try FCE to Auxiliary. What the hell is that?” Conrad questioned Mission Control.

“SCE – SCE to Auxiliary,” Mission Control slowly repeated with emphasis.

“Try the buses. Get the buses back on the line,” Conrad urgently called out to the other two astronauts in the Command Module.

Meanwhile, there was genuine concern Mission Control would need to abort the Apollo 12 mission.

Fortunately, astronaut Alan Bean was familiar with the SCE switch located inside the command module. Turning around in his seat, he flipped SCE to AUX, which restored and normalized Apollo 12’s instrumentation data and telemetry transmissions.

Apollo 12 was able to complete its mission to the moon and visit the Surveyor 3 lunar lander.

Sadly, each year we are losing more astronauts who took part in those historic Apollo moon missions.

Apollo 12 Commander Charles “Pete” Conrad Jr. died July 8, 1999, Command Module Pilot Richard Gordon Jr., Nov. 6, 2017, and Lunar Module Pilot, Alan Bean, passed away May 26, 2018.

A July 9, 2013 photograph taken from the moon orbiting Lunar Reconnaissance Orbiter shows the Apollo 12 Intrepid descent stage and the Surveyor 3 lunar lander on the moon’s surface. You can see this photo at https://go.nasa.gov/3dSRn6l.

My Apollo 12 "SCE to AUX" coffee cup, Lunar Module,
 and Astronaut.