Sunday, March 25, 2012

Deepsea Challenger: Now more challenging to follow

The Deepsea Challenge project tweeted five hours ago (#DeepChallenge) that contrary to the  previous "OK to go" note from James Cameron, it didn't launch on Sunday, Guam time, after all. The latest Twitter note:
and the team are still waiting for the right diving conditions. We will share updates as they come in.
That explained ship movements otherwise inexplicable. That is: Mermaid and Barakuda's AIS positions suggested the project had launched the sub and/or landers sometime Sunday, but then AIS feeds indicated that late Sunday night (Guam time) the ships packed up and moved rapidly away, stopping several dozen miles to the east, where Mermaid then went into a pattern suggesting a recovery effort. 

Here's a screen shot of AIS data from Mermaid at that time:


What caught my attention, and seemed to support some kind of recovery, was the zig-zag on the left. When a submersible is coming up as fast as Cameron's does, a mother ship backs off a half-mile or more, so it seemed to suggest a recovery.

But that didn't make sense either. Puzzled followers were trying to figure out how Cameron's sub (chiefly designed for vertical movement) could be launched and then surface many miles away, far beyond the capability of its horizontal thrusters and batteries. 

So where did our Waldos go? Here's a screenshot putting the two relevant locations as arrows on a Google map:
Note that the previous location, and the newer one, are over the Mariana Trench, according to Google's depth profile. That supports current speculations by followers that the project is planning another launch attempt on Monday, Guam time. 

Given the paucity of updates from the project, Facebook fans and bloggers like BoneInItsTeeth were depending on AIS to follow developments, because it was the only real-time information available, other than NOAA weather reports.

About AIS: Drawing data from their GPS receivers, ocean-going vessels have transponders on board that relay their whereabouts through the Automatic Information System (see my post on Concordia for more background on AIS). Typically we get updates every few minutes, showing up as points on a course.

But an hour ago, all four ships in the fleet (three associated with the Deepsea effort, plus Paul Allen's megayacht Octopus, which joined up on Sunday) stopped beaming up their AIS positions. Humph! Maybe they've moved somewhere else since then.

For a string of posts and screenshots on what the AIS data was showing until it was shut off, check out BoneInItsTeeth. From one recent post:
Right now his big support ship, the Mermaid Sapphire, is the better part of 50 miles away from where they were last night.  Interesting, too, is the fact that Paul Allen's superyacht, Octopus, has been keeping pace with the Mermaid Sapphire throughout the transit period.
When AIS data is up again, you can monitor movements at MarineTraffic

Now for Speculation Corner. The bits of information I've seen would be consistent with a scenario like this: The team starts the multi-ship process to launch the mission on Sunday at mid-day, beginning with the landers, since this has to be done well in advance of Cameron's plunge. Barakuda drops a lander, which starts to descend. But then there are problems handling Deepsea Challenger given the sea state, or perhaps some technical problem. The team scrubs Deepsea Challenger's launch late in the day. On Sunday evening, Mermaid relocates to another part of the trench. Once Barakuda has its lander back on board,  a few hours later, it leaves the site to rejoin the others.

A problem with my scenario is that it's hard to see why the team would move 40-odd miles. Maybe new information, just in, indicates the mission goals would be better served in the new spot. Any ideas?

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