Schmitt: “Going down at five [feet per second]. “The fuel’s good. One hundred ten feet. Stand by for some dust.”
As Challenger’s radar altimeter passed through 80 feet, both commander and pilot noticed faint tendrils of dust being kicked up by the LM’s descent engine. With no atmosphere to lift it skyward, the lunar dust silently skimmed the surface as it shot out from under Challenger in all directions.
On Challenger’s instrument panel, between the commander and the LM pilot, there was a small blue light labeled “lunar contact.” The bulb’s sole purpose was to illuminate when one of three 5.6-foot-long probes that extended below Challenger’s footpads crunched into moon and completed an electrical circuit. It was the LM pilot’s responsibility to notice when the contact light went on.
“Contact,” said Schmitt.
Cernan’s gloved right hand immediately shot out. The LM’s two most important buttons were the red abort button and the blue engine-stop button. Cernan hit the blue button. “That’s when the bottom falls out,” says Cernan. “You hit zero-G again for a second and then you hit.”
Challenger impacted the Valley of Taurus-Littrow at a leisurely three feet per second, well within the LM’s structural limit of 10 feet per second. But because Cernan and Schmitt had lived in zero gravity for four days, the impact felt like a ton of bricks.
“The light came on,” wrote Apollo 15 LM pilot Jim Irwin in his book, To Rule the Night. “I called ‘Contact!’ Dave hit the button to shut off the engine and we hit hard. It was the hardest landing I have ever been in. Everything rocked around and I thought the gear was going to fall off.”
In any LM’s life, landings are the moment of truth. “Touchdown is the most acceleration that the vehicle is going to feel,” says Schmitt. “If something is going to break, it is probably going to break at touchdown.”
Schmitt, like all LM pilots before him, was just as busy after touchdown as he was before. “There was no time for congratulations and popping of champagne corks,” says Buzz Aldrin, who flew on Apollo 11. “It was a busy time to be ready to respond because your life and the mission depends on that.” Schmitt spent the next couple of minutes analyzing everything from cabin pressure integrity to battery ampere hours remaining. Finally, after confirming that Challenger was not hemorrhaging fuel or otherwise in trouble, the commander and LM pilot took their first long look at their new digs.
Schmitt: “Oh man, look at that rock out there!”