Last Day for ENDURANCE

3 12 2009

The final day for ENDURANCE has come and gone. We started off with a successful mission, getting in the last bathymetry, and also a few field demonstrations of new robotic capabilities.

Kristof, Chris, Emma, Vickie, Rachel, Shilpa, Peter and Bill pose with ENDURANCE after its final mission.

Then it was time to start packing up. ENDURANCE is much too heavy, and has too many fragile instruments, to be transported fully assembled. The syntactic flotation has to come off, the sonde, DVL, USBL, cameras, batteries, etc., have to be removed and packed up. So we spent the rest of the day making sure we’d be ready for the first sets of helo flights of our stuff scheduled to go out tomorrow.

I work on removing one of the syntactic flotation blocks.

Bill, Peter and Chris working on packing the syntactic blocks into boxes for shipment back to McMurdo.

Peter, Emma and Bill working on disassembling ENDURANCE and packing up the 'bothouse.


2 12 2009

Today, we had another successful run through the narrows into the east lobe of Lake Bonney with 4 km traverse, 8 sonde drops and bathymetry coverage of 30% of the lake. Ho-hum. I’m going to talk about Zen.

The Zen Garden, that is. Behind the ridge above Lake Bonney Camp, about half-way up the side of the valley, is a wide shelf covered with the cinders from a small cone further up the mountainside, undisturbed for millions of years by water or ice. Only the howling Antarctic winds have come through and carved amazing shaped out of the larger boulders which lie strewn about on the bed of small reddish pumice pebbles. It truly bears an uncanny resemblance to a manicured Japanese sculpture garden, and last Saturday, when we celebrated Thanksgiving, it became the goal of a small hike I took in the afternoon. It was probably the most unforgettable place I’ve ever been.

The high shelf holding the Zen Garden. The cinder cone on the side of the mountain to the right of the Sollas Glacier is the source of the reddish pebble field covering the plain below. The boulders are chunks of the surrounding bedrock.

A typical view in the Zen Garden.

I had the best time running around from rock to rock. This one rested just so, that one had ridiculous holes carved through it, the view behind that one was stunning. Each was better than the next.

The fragile shapes left by the carving of the wind are completely unbelievable. This was once a four-foot diameter boulder. The wispy shell is all that remains.

The Zen Master contemplating the oneness of all existence.

Winding Down

1 12 2009

The days left at Lake Bonney are becoming very few. ENDURANCE has completed all of the major science objectives: profiling the entire west lobe biogeochemistry, obtaining bathymetry of the entire lake, exploring the contact between the glacier and the lake bed. And it’s demonstrated the engineering objectives to make it all possible, too. Yesterday, ENDURANCE completed a mission where we detached the communications fiber after it was initialized in the water. It got all the data, found its way back to the melthole and came right up to the surface—all by itself.
Now we’re trying to figure out what else to do to really show off its capabilities. Not that we’re lacking in ideas. ENDURANCE is proving to be a great platform for experimenting with new ways of doing robotic science in extreme environments, just as everyone had hoped. I’m working on a method for ensuring ENDURANCE can get back to the melthole, even if the DVL navigation sensor has a failure. Chris is perfecting the automated sonde drop routine to handle the outages the sonde’s sonar altimeter is experiencing due to poor reflections off of the soft lake bottom sediments. Shilpa is updating the system executive module to properly handle the new functionality. We hope to pull off a totally autonomous mission with full science sampling and return home in the face of some outages by the time we leave.

Missions have become much less stressfull. As opposed to the early days where we were constantly monitoring telemetry, issuing commands for things that ENDURANCE couldn’t yet do on its own, tracking from the surface to make sure we had exact GPS coordinates for sonde drops, the ‘bot is now pretty much off on its own.

Bill, Chris, Shilpa, and Peter watching the sonar data visualizer, waiting around for the 'bot to finish its mission.

We still “watch over its shoulder” via the data coming on the fiber-optic tether, but there’s not much else to do for missions once the bot is initialized and sent off in the morning.

For a change, Vickie gets a rest and Shilpa tends the fiber while the 'bot is out doing its rounds. Up till recently, Vickie would be out on the ice tracking the 'bot's magnetic beacon and getting GPS fixes for sonde drop locations, and Shilpa would be at mission control checking telemetry, issuing commands, writing comments in the data log, etc.

Hmm, Shilpa doing the fiber tending seems to have a calming effect on everyone.

Well, not on everyone. (Bill doing push-ups).

The Fateful Day

25 11 2009

Well, y’all, we did it. Today, ENDURANCE made it under the Taylor Glacier.

Here’s how it went:
To start off the day, we drove ENDURANCE over to a second melthole which Professor Peter Doran, Principal Investigator and Papa Ice Finegler had melted near the glacier face. ENDURANCE found and came up through this hole without a hitch. There, we weighted ENDURANCE down with 230 lbs. of lead so that it would become heavy enough to penetrate the halocline (salt water boundary) and move into the very salty lower lake waters. Here’s a capture of our real-time 3-D visualization of the sonar data it collected after it went back down the hole and down to 22 m depth:

ENDURANCE hovering below the halocline, looking under the mystery ledge. The red is the lake ice above, the orange and yellow is the glacier face, with the ledge which hid the view of the lake bottom sticking out towards the bottom, the green is the lake bottom.

Finally, ENDURANCE could see under the ledge which had hidden the important contact between ice and lake floor from our view since last year. As you can see, the cavern doesn’t extend back too far, but far enough that we could go in for a closer look.
This was it, moving in under the Taylor Glacier. Carefully, Shilpa executed the command telling ENDURANCE to move ahead toward the glacier. We all watched the sonar data coming back intently. How far would ENDURANCE be able to penetrate? Would we be able to see the grounding line where the ice meets the lake bottom, and where tantalizing water temperature and chemistry signatures that ENDURANCE has been picking up might be originating?
ENDURANCE proceded forward.

ENDURANCE exploring under the mystery ledge. The red and yellow rays projecting from ENDURANCE show its obstacle avoidance sonars, the blue fan represents the DeltaT multibeam sonar.

As you can see, it got right up close and under the ledge. Unfortunately, there was too much dust in the water, and the end of the cavern pinched off in too narrow a V for us to get any clear visual view in the forward camera.
We tried a few other locations along the glacier wall, but found that there was a little too much ballast on ENDURANCE, and it couldn’t quite come up high enough to successfully see the sought-after grounding line. So tomorrow’s mission will call for the same procedure, with about 40 lbs less ballast, which hopefully will allow ENDURANCE to maneuver in close enough at the proper depth. But, gosh durn it, ENDURANCE has swum under the glacier!

(Note: The internet was out again yesterday, probably because it was overcast and snowing all day, and the solar panels on Peak 1882 were covered and unable to recharge the repeater batteries. We’ll see how everything holds out for the next few days…)

The Daily Commute

23 11 2009

My daily update schedule has gotten a bit out of whack due to the extended internet outage, so I’ve decided to take more of a themed approach to my posts. Here is the first in such a series: the joys of commuting in the Dry Valleys.

Lake Bonney Camp is located on the east lobe of Lake Bonney about 4 km as the crow flies from the bothouse on the west lobe, which ENDURANCE calls home. In order to get from place to place on the lake, we are provided with swank 6-wheel ATVs which can be driven on the ice. (To avoid damaging the fragile soil ecology, no driving on dirt is permitted.) These then provide us with transportation for the Lake Bonney daily commute, which takes about 20-25 minutes. (Rush hour is usually around 9:00-9:30 am and another half hour sometime in the evening).

Emma and me in an ATV in front of Bonney Camp, ready for the morning commute.

Bart, Chris and Rachel taking in one of the sights along the way: a mummified seal who got lost in the valley possibly thousands of years ago.

On the West Lobe connector. The ablating (basically means eroding) permanent ice makes this the bumpiest part of the ride.

On the Inter-Lobe Expressway. The seasonal ice re-freezes smooth every year. Of course, this means it doesn't last through the summer, and currently is beginning to get rougher and more broken up. Even down here you have to deal with potholes.

Saddling up at the bothouse for the evening rush hour.

Rachel has also posted an awesome video of the commute on Facebook, which you may be able to view, depending on your level of friendliness to both of us.

Waiting for the Batteries

22 11 2009

(Nov 23, 2009: I just found this draft, which I apparently was working on when the internet went out.)

No pictures again today. Chris took back his camera to record some of the things he was fixing inside of the main processor housing, and then left the camera in the ‘bothouse. I’ll upload some pictures tomorrow.

We figured out that yesterday’s problems were caused by a dirty wire where the router for the network in the robot is plugged into the power supply. This was causing the router to turn off from time to time and caused the network outage we saw.

While debugging things yesterday, Bart also figured out that the new batteries are having some problems which essentially cause them to have to shut down with about 20% of their power still available. This might have been contributing to our battery problems in the last few days. So while we had the ‘bot taken apart, we also took apart the batteries. Bart is working on some fixes at the moment, while the rest of the team is back at camp eating dinner. When he finishes up, he’ll put the batteries back on charge, and we’ll have a team head out early tomorrow morning to put them back together and re-install them in the ‘bot.

The weather is excellent. Our outdoor thermometer is reading 2 °C, though it is in the sun, so it’s skewed high. I plan to go out for a little run tonight before heading off to bed.

Lake Bonney Jamesway Activities

22 11 2009

In addition to all of the science being done in Lake Bonney with ENDURANCE, we’ve also had an interesting social experiment take place down here in the last 10 days. Viz:

Activity in the Jamesway while the Internet repeater was down.

Activity in the Jamesway after Internet was restored.

Everyone answering emails and updating blogs does take a toll on the talking, game-playing, carousing, and so on.

Be sure to check out Shilpa’s posts and the Stone Aerospace blog for more details on all the stuff we’ve been doing with ENDURANCE. I’ll come back more on that tomorrow.