Deliberate Delay

Kelly Lake, British Columbia, Canada
Tuesday, July 18, 2011

Principal Investigator Darlene Lim in her role as CapComm during PLRP’s first test of delayed communications. Credit: Henry Bortman

On the first day of sub operations at Kelly Lake, the delays were unintentional. Those bugs were worked out overnight, however, which enabled the Pavilion Lake Research Project (PLRP) team to begin an experiment in which delays were introduced into the process on purpose.

Not delays in the schedule. These were delays in communication.

You know how sometimes when you make a long-distance phone call, and the call gets routed through an orbiting satellite, there’s this annoying pause between when you talk and when the other person responds? That’s because it takes a fraction of a second for the signal to travel, at the speed of light, from Earth to the satellite and back again.

Now imagine that, instead of being a fraction of a second, the delay is a minute and 40 seconds long. It would be hard to have a meaningful conversation. But that’s precisely what the PLRP team introduced into their communication stream on Tuesday. The experiment simulates what communication will be like with explorers who some day travel to a near-Earth asteroid.

As Mike Gernhardt, an astronaut who has flown on four Shuttle missions, and also is a PLRP sub pilot, explained, “We are targeting the asteroids or possibly the moons of Mars as possibly the next big step in human space exploration. And one of the things that’s very different about that, compared to what we’ve done all throughout NASA’s history, is that we won’t have real-time comm.” “Comm” is NASA-speak for communications.

“We want to understand the effects of delayed comm on how we do the exploration operations,” and even on “the design of the spacecraft that we’ll use to do those tasks.”

First, though, the big picture.

The two DeepWorker subs are out at Kelly Lake. Also at the lake are two small “nav” boats crammed full of people and electronic equipment. They follow the subs, monitor their status and communicate directly with their pilots. Seventeen kilometers (ten and a half miles) away, in the parking lot of the Cariboo Lodge in Clinton, BC, is a huge NASA trailer, the MMCC (Mobile Mission Control Center), also crammed full of people and electronic equipment.

NASA astronaut and PLRP pilot Mike Gernhardt prepares for a DeepWorker sub flight. Credit: Henry Bortman

In past years, there was no direct communication between the pilots in the subs and the people in the MMCC They had to communicate with each other through intermediaries on the nav boats. This year, though, one of the subs is “tethered” to its nav boat via a fiber-optic cable. (It’s that yellow cable in the banner photo at the top of this page.) The nav boats in turn are connected, via a series of antennae, back to the MMCC.

This enables the pilots to communicate directly with the folks in the MMCC, a rotating group of scientists referred to as the science back-room team. It also enables the science back-room team to view live video captured by the video camera on the front of the tethered sub.

So the communications experiment is really a two-part experiment. The first part is live real-time communication between one of the sub pilots and the science back-room team. The second part introduces a 50-second delay, in each direction, into that communication stream.

The question is, how do these variations in communication affect the productivity, the scientific output, of the sub pilots?

On the first tethered flight, Gernhardt was the pilot and Darlene Lim, PLRP’s principal investigator was the CapComm, the person responsible for talking to the pilot. Everyone on the science back-room team could hear Gernhardt and see the video he was capturing, and they could talk to Lim, but only Lim could talk directly to Gernhardt.

So the scene during the real-time communications was like this: a room full of excited scientists, watching live video of microbialites and listening to Gernhardt’s running commentary about what he was seeing; the scientists having a million questions, which they voiced out loud; Lim trying to sort through which of their questions to relay to Gernhardt; and Gernhardt trying to accomplish what the scientists were asking of him.

“The first time we did real-time comm, it was the first time the scientists got to see all that stuff [the video] and they were very excited. So they were kind of jerking me around like a dog on a leash. It was like, ‘Do this, do that, do the other thing,’” Gernhardt said. He wasn’t complaining, mind you, merely describing what happened.

That was the real-time portion of the experiment. Then came the delayed-comm portion.

NASA’s Mobile Mission Control Center, where live video from tethered sub flights can be monitored. Credit: Henry Bortman

“I was expecting it to be a Gong Show,” Lim told me afterwards. “I thought, you know, we’re gonna wanna get input to him, it’s gonna be confusing, we’re gonna step on each other so that we’re behind in the transmission, and it’s just gonna get awful.”

This was not mere nervous worry. A test a month earlier between Lim and Donnie Reid, PLRP’s dive safety officer, underwater photographer and logistics wizard, had not gone particularly well. “I thought he hadn’t got my message yet,” Lim said, “and then he thought I hadn’t—and so we started to say, ‘Did you get it?’ and you know, it was a disaster.”

But when the real thing happened Tuesday, “It turned out to be 180 degrees different,” Lim said. “When we went into delayed comms … we could visibly hear Mike just sort of relax and enjoy himself because he knew that we weren’t going to be … asking him anything in real time.”

The science back-room team relaxed, too. What had been a buzzing hive of chatter a minute before went silent, as though the lights had just gone down in the theater and the movie had started.

The science return improved, too. Gernhardt is quick to point out, however, that several factors contributed to his difficulties during the first part of the flight.

“I had a headset that didn’t fit right, it was falling off my head, the camera control was upside-down, and then we were on the part of the lake that was really murky, I could barely even see the bottom.” In addition to “the lack of discipline with the real-time back room.” And when “you put all those things together and you get this really high workload.”

The view from the hill above the eastern shore of Kelly Lake. Credit: Henry Bortman

In the assessment system PLRP uses to rate various aspects of each sub flight, Gernhardt said he normally rates his workload as between three and six. “My workload was closer to eight during the real-time comm. And then when we shifted” to delayed comm, “for me it was like we just flipped a switch. All of a sudden, I had much more brain cells to focus on flying the sub and doing the observations.”

“So it doesn’t mean that real-time comm is bad,” he said reflectively. Just that it could have been better. But that’s the point of doing experiments. You learn things. For example: “The next time we do real-time comm we’re going to exercise more discipline.”

Meanwhile, although I did observe part of the comms experiment from the MMCC in the afternoon, I spent the morning climbing up a very steep hill on the east side of Kelly Lake, through scree and loose soil, to gain a vantage point from which I could capture a panoramic view of the lake.

Using a GigaPan Epic, a small robotic device that has its roots in the panoramic cameras on the Mars Exploration Rovers, I took a series of 91 pictures, which I stitched together into a 135-degree-wide panorama, using software that comes with the device. You can view the panorama here. See if you can find Gernhardt. He’s on the barge.

PLRP field operations will continue through the rest of the week. If you have a question for someone on the PLRP team, click the red Ask a Question button and send it in. We’ll get you an answer as quickly as we can.

(My thanks to Mike Pryor of Clinton, BC, for being my trail guide—especially because there wasn’t really a trail. And thanks to Darla Pryor for helping figure out where I could go to shoot the panorama. Darla and Mike, by the way, own the Cariboo Lodge, where the MMCC is parked.)