45 Years after Apollo 11, NASA Prepares for Another Big Splashdown
This Sunday, July 20 marks the 45th anniversary of the first time humans set foot on another world in 1969. When Neil Armstrong and Buzz Aldrin climbed out of the lunar module Eagle to spend two and a half hours exploring the surface of the moon, 125 million Americans watched it live. That’s about 63 percent of the entire population.
Less notably, July 24 marks the 45th anniversary of the Apollo 11 splashdown. Everyone remembers what Neil Armstrong said when he stepped on the moon, but fewer recall the voice transmissions that signaled his crew’s safe return to Earth:
Swim 1 (recovery helicopter): Swim 1 has a visual. Dead ahead about a mile and a half? [Garble].
Swim 1: Roger. You're looking real good. [Long pause.]
Swim 1: Splashdown! Apollo has splashdown.
Hornet: Hornet, copy. Understand splashdown.
Neil Armstrong, Buzz Aldrin and Michael Collins were safely back on Earth—but not yet on solid ground. Their spacecraft command module, Columbia, bobbed in the ocean as the U.S. Navy swooped in.
Hornet: Affirmative. Determine the present condition of the astronauts?
Air Boss (radar airplane): Hello. This is Air Boss 1 - [what is] your condition?
Michael Collins: Our condition is all three excellent. We're just fine. Take your time.
Air Boss: All right. Okay.
Navy divers helped the astronauts out of Columbia and into a small boat. The lunar explorers donned biological isolation suits—NASA hadn’t yet ruled out the possibility that the moon harbored dangerous microbes. One by one, the astronauts were reeled upward into a helicopter. Another copter pulled Columbia from the ocean and deposited on the Hornet’s deck.
Apollo 11 after splashdown
The crew of Apollo 11 sits in a raft next to the command module Columbia shortly after splashdown on July 24, 1969. The crew wore biological isolation suits in case they were carrying pathogens from the lunar surface.
A new version of this scene is scheduled to play out in 2021, when the first crew of astronauts aboard NASA’s next-generation Orion spacecraft splash down into the Pacific Ocean. There won’t be any decontamination procedure, and the astronauts won’t exit their spacecraft while it floats in the open sea. Instead, Orion and the crew will be towed to an LPD (Landing Platform/Dock) amphibious assault ship—probably the U.S.S. San Diego. LPDs have floodable rear well decks with yawning, 50 by 200 feet entrances. Once the spacecraft is safely secured inside the ship, the deck will be drained, and the astronauts will exit.
Humans won’t ride in Orion until 2021. But in December, an uncrewed version of the capsule will be sent around the Earth for a two-orbit shakedown cruise.
A team of U.S. Navy divers retrieve a test version of the Orion spacecraft's forward bay cover during recovery training. The forward bay cover protects the spacecraft's parachutes during launch and reentry.
Mike Generale, the Orion recovery operations manager and recovery test director at Kennedy Space Center, said that NASA and the Navy successfully recovered the forward bay cover and parachutes. They also demonstrated proper coordination with mission control in Houston. But when it came time to pull the Orion BTA out of the U.S.S. San Diego’s well deck, things got a little tricky.
The waves in the Pacific that day began steadily rocking the San Diego from bow to stern. Every time the stern lifted, more waves came crashing into the well deck, causing the water in the ship to slosh back and forth. Orion bounced and jostled. Line handlers on the well deck’s wing walls struggled to maintain control. And some of the tending lines got caught on the capsule’s recovery cradle. It was all too much—the team needed to stop and regroup.
Generale said his team has been busy coming up with fixes that they’ll try out during another test in August. They’ve built a collar with extra tending line attachments that wraps around the spacecraft. Bumpers may be installed on the well deck to contain the capsule. And there’s a capture net in the works that could be flung over the entire spacecraft.
Finally, there’s the LLAMA.
“The KSC (Kennedy Space Center) prototype lab has developed a device that we affectionately refer to as the LLAMA,” said Generale, chuckling as he tried to recall what the acronym meant. “Load Limiting Apparatus Mechanical Assembly—something like that,” he said, adding, “We had a little fun with that.”
LLAMA works like a drag system on a fishing reel. A drag system varies the tension on a fishing line so that a hooked fish is able to pull on the line without breaking it. This also makes it easier for the fisher to reel in the catch. Likewise, LLAMA varies the tension in Orion’s tending lines so they can give as the spacecraft bucks around—helping the line tenders better control the capsule.
All of this should help get the Orion BTA out of the well deck for its tests, but what if similar problems stymie the recovery? Generale has a plan B. LPD ships have cousins called LSDs, or Dock Landing Ships. LSDs have large cranes that could pull the spacecraft out of the water and set it on the ship’s upper deck. Since LPDs like the San Diego also have cranes, the upcoming August tests may include a simulated crane recovery. Orion will be fitted with a lifting harness and briefly pulled from the water. “If we don’t find any showstoppers with that,” Generale said, “we’d press on to a full demonstration with an LSD class ship.”
How all that will work isn’t exactly clear, but no matter where a NASA mission to Mars begins, it will probably end in the ocean. And when that happens, the Navy will be waiting, just like they were for Apollo 11.
Boilerplate Test Article on the well deck
The Orion spacecraft's Boilerplate Test Article (BTA) sits at the end of the U.S.S. San Diego's flooded well deck during recovery training in February.