January 29th, 2010:

While out on an EVA today, Darrel broke his leg. He had someone with him, of course—in this case, Mike—who was able to radio back to the Hab about the accident and request emergency assistance. Brian, Carla, and Kiri quickly suited up, and Luis remained behind to serve as HabCom and monitor our progress via radio. Twenty-one minutes later, we were exiting the airlock and on our way to rescue our downed crew member.

Lest the reader be overly anxious at this point, I should explain that Darrel didn’t really break his leg. We had decided to test our ability to respond to an emergency in which one crew member was unable to move. Carla and Brian spent the morning constructing a sled that could be used to drag someone back to the Hab behind an ATV. When the emergency call came in at 3:04 p.m., we all leapt into action. I plugged the coordinates that Mike reported into my GPS unit (fumbling a bit as I hadn’t ever tried to enter coordinates manually before—lesson learned!). We suited up in record time (13 minutes). Outside, Brian attached the sled to the Viking-1 ATV and kicked it into gear. Carla and I trailed along in his wake, on foot.

We had stepped out into a snowy, misty world, where visibility was limited to about a quarter-mile. The sun lit up the fog, shedding silvery light all around us, and the hills were white mounds with patches of red peeking through on the south-facing slopes. Crunching along on the snowy road, we could see that we needed to head northeast to reach Mike and Darrel. The road would be more convenient for the sled, but their footprints led off to the north and we wanted to be sure we could reach them. So we headed off over the lumpy snow. (Our out-of-sim concerns about avoiding off-road ATV use were allayed by the thick layer of snow.) Viking-1 performed heroically, and the sled slid along behind in fine form.

We walked and walked, hoping with each rise that we’d suddenly see Mike and Darrel. But each time we were only rewarded with new views of their twin footprints, leading us onward. Finally, at 3:45 p.m. and about half a mile from the Hab, we crested a larger hill and discovered our fallen comrade, attended by Mike. We couldn’t get the ATV up to the foot of the rocky cliff where he’d “fallen”, so we lifted and carried him down to the ATV and sled. At that point we discovered that we were only about 40 yards from Lowell Highway, so after strapping Darrel to the sled, we continued on to the highway. Turning onto the snow-covered, graded road, we were able to make better time. We were back to the Hab by 4:35 p.m., at which point Darrel was again carried up into the airlock and, after depressurization, Luis was able to attend to his injuries.

A video of the rescue operation is in the works!

Another notable achievement for the day: Darrel and Luis put Viking-2’s carburetor back together and installed it, but so far no luck in starting the ATV. We’ll keep trying.

In the evening, we assembled for our second group exercise session. This time, Luis was our instructor and taught us basic capoeira moves—and wowed us with his advanced spinning and kicking! We all got a good workout (and no doubt entertained any webcam watchers). Now we’re busily filing reports and anticipating a tasty AlpineAir meal: Leonardo da Fettuccine.

The goal of this exercise is to live and work in a simulated Mars environment. But obviously we aren’t actually on Mars, and it is physically possible to go outside and breathe the atmosphere here (although it has been so cold that actually surviving the night outside the Hab would be challenging!). So during the mission, we distinguish between things done “in sim” (imposing constraints as if the outside environment were Mars) and “out of sim” (reverting to actual Earth constraints).

As you’d expect, we strive to do everything possible in sim. The day a new crew arrives is an exception, since there are 12 people (but only 6 suits) and a lot of information has to be conveyed in a short time, walking around to see and learn all of the systems. But after that, we are confined to our Hab, or going out in suits, aside from our “pressurized tunnels” that connects the Hab to the GreenHab (water recycling), “pressurized garage” where the ATVs live, the Musk Observatory, and the Engineering Station where the generators and fuel supplies are. These aren’t enclosed, but we pretend they are, since in a real landed mission the crew would likely have erected just such connections so that they could access those critical systems not actually in the Hab. The tunnels are delineated with rock-lined paths, so we are careful not to step outside of them.

But of course, staying in sim has its tedious downsides (that’s part of what you learn from this experience), like when you’re in your spacesuit and you get halfway through the 5-minute wait to “depressurize” the airlock, then remember that you forgot to grab the ATV keys. You could “break sim” to reach back inside and get the keys, or stay in sim and wait to repressurize the airlock, go inside, get the keys, return to the airlock, and wait to depressurize again. In this case, we opted to have another crew member run the keys outside (through the pressurized tunnel, to the pressurized ATV garage) and put them in the ATVs—since on Mars, we wouldn’t bother to bring the keys in and out with us. (It is incredibly remote here, but in theory it is possible for other people to wander down the road to the Hab and therefore the ATVs could be stolen, if we left the keys in them all the time.) But each such snag has to be worked through logically, to determine what would or would not be possible in a Martian environment, so that we can keep the simulation fidelity as high as possible.

So far we have opted in every such case, but one, to stay in sim, including two days ago when an EVA crew had to come back in and go through the pressurization/depressurization cycle to retrieve sunglasses (the snow was too bright!). As a result, EVA 7 became EVAs 7 and 8, and of course, this took up more time than planned.

The one exception to staying in sim was on EVA 8, when Carla’s helmet fogged up so much that she could not see where she was walking! After trying a variety of methods to deal with the condensation, she finally gave up and took off her helmet. In a real mission, she would probably have put her arm on another crew member’s shoulder and followed them, blind, back to the Hab. We had a good time joking about “dead” Carla, and considered holding a memorial session for her that night, but she declined. 🙂 Meanwhile, Brian’s helmet was just as fogged, but he was too darn stubborn to take it off!

This experience also got us thinking about other good exercises to conduct on EVA. What if a crew member were physically incapacitated and could not get back to the Hab under their own power, even being led? Previous crews have experimented with a fireman’s carry. We’ve decided to try a strategy based on our current weather conditions (3 inches of snow on the ground). I can hear some of the crew outside sawing and assembling a sled. We plan to have one EVA crew go out, get far enough to be out of line of sight, and then have a simulated accident in which one crew member cannot move. At that point they’ll radio back their GPS coordinates, and we’ll send a second crew out on the ATVs, with the sled, to rescue them. We’ll report back on this ambitious plan and what we learn from the attempt!