Ice Fracture Explorer: theoretical model for a mission to Europa

Paul Raven @ 16-08-2010

Joseph Shoer of Quantum Rocketry doesn’t post all that often, but every now and again he puts out a gem. Here he is imagining what you’d need to do to put together a robotic mission to explore Europa, the Jovian moon that’s mostly ocean with a thick icy crust, complete with little diagrams of what the modules might look like:

As Jupiter rises overhead, its tides will pull apart the two sides of the ice fracture. The IFE will be suspended in the middle as the crack opens, with nothing below it until the ocean 1-10 km down! At this point, the IFE will drop its deflated cushions and begin to deploy a smaller penetrator vehicle from its underside. The penetrator is a small, two-stage vehicle with two instrument packages, a hard-shell body, and a data line connecting it to the IFE’s main bus.

Pure hard-SF space geekery of the best type. As Shoer points out, manned missions to Europa are pretty much a non-starter; even if we could get people there, the radiation would roast them pretty quickly. But throw some transhuman moravec explorers into the mix, and you’ve got the start of a great story…

Speaking of marine conservation…

Tom James @ 27-08-2009

garbage_in_ocean…as we were, here is news of the first incursion into the collossal garbage patch that has collected in the Pacific Ocean:

Scientists surveyed plastic distribution and abundance, taking samples for analysis in the lab and assessing the impacts of debris on marine life.

Before this research, little was known about the size of the “garbage patch” and the threats it poses to marine life and the gyre’s biological environment.

On August 11th, the researchers encountered a large net entwined with plastic and various marine organisms; they also recovered several plastic bottles covered with ocean animals, including large barnacles.

“Finding so much plastic there was shocking,” said Goldstein. “How could there be this much plastic floating in a random patch of ocean–a thousand miles from land?”

This reminds me of the great junk armada depicted in Snow Crash by Neal Stephenson.

[via Physorg][image from Physorg]

Boat-cleaning robots for a greener ocean?

Tom Marcinko @ 24-08-2009

autonomousunBarnacles, oysters, algae, and other sea-life can slow a ship by 10% and increase fuel consumption by as much as 40%. The U.S. Office of Naval Research is testing a Roomba-like autonomous hull-cleaning robot to cut the drag.

The robot incorporates the use of a detector that utilizes modified fluorometer technology to enable the robot to detect the difference between the clean and unclean surfaces on the hull of a ship. Used to groom ships in port, the Hull BUG [Bio-inspired Underwater Grooming tool] removes the marine biofilm and other marine organisms before they get solidly attached. This is especially important because Navy ships spend more than 50 percent of their service life in port, giving barnacles and marine life ample time to become settled and, if allowed, to further colonize and grow on the ship’s hull.

Underscoring the benefits of combining the Hull BUG with newly developed environmentally benign antifouling hull coatings, [ONR Program Officer Steve] McElvany estimates that “the Navy will save millions of dollars per year in fuel. Using less fuel also means less carbon dioxide in the atmosphere.”

[Photo: U.S. Navy]

When geoengineering goes wrong

Paul Raven @ 26-03-2009

Barcelona sunsetWhile it’s probably a bit too soon to go rushing into geoengineering projects in an attempt to readjust the earth’s runaway climate, discussing the ideas thoroughly is of great benefit – principally because it gives people a chance to pick holes in the plans and think of potential downsides before we do something irreversible.

Exhibit A: seeding the atmosphere with dust to increase the amount of sunlight reflected away into space might actually be shooting ourselves in our renewable foot, so to speak:

While such atmospheric modifications would only be expected to deflect about 3 percent of the sunlight incident on the earth, Murphy has found that solar energy collectors would face a reduction of up to one-fifth of the usable energy that they collect presently. Even though 97 percent of the sun’s light will make it through the Earth’s modified stratosphere, much of it will be scattered, making the light diffuse. Diffuse light cannot be focused in the same manner that direct light can be, which lessens its usability in most optical systems. Almost all projects that harness solar energy require a large portion direct sunlight that can be focused and concentrated on a cell of some kind.

So: reduce the bad effects of sunlight, and you’ll reduce the useful ones as well. Best relegate that plan to the back-burner… at least until someone finally develops a usable fusion system.

On a similar note, it looks like iron-dumping in the ocean is off the menu at least for us. For a certain type of shrimp, however, it’s very much on the menu:

The iron triggered a bloom of phytoplankton, which doubled their biomass within two weeks by taking in carbon dioxide from the seawater. Dead bloom particles were then expected to sink to the ocean bed, dragging carbon along with them.

Instead, the bloom attracted a swarm of hungry copepods. The tiny crustaceans graze on phytoplankton, which keeps the carbon in the food chain and prevents it from being stored in the ocean sink.

Back to the drawing board. Thank goodness for thinking ahead, eh? [image by papalars]

Google Ocean marks (unsurprisingly) aren’t Atlantis

Paul Raven @ 25-02-2009

Leading on from one discussion of reporting style to another, did you hear the one about how the new Google Ocean maps of the sea floor revealed a rectangle the size of Wales comprised of straight lines intersecting at right angles? In exactly the place that some ancient writers suggested as the location of Atlantis?*

seabed markings on Google Ocean - not actually Atlantis, OK?

Well, sorry to disappoint, but it turns out that the markings aren’t the work of an ancient civilisation or marauding aquatic aliens after all:

The scientific explanation is a bit less exotic, but we think it’s still pretty interesting: these marks are what we call “ship tracks.” You see, it’s actually quite hard to measure the depth of the ocean. Sunlight, lasers, and other electromagnetic radiation can travel less than 100 feet below the surface, yet the typical depth in the ocean is more than two and a half miles. Sound waves are more effective. By measuring the time it takes for sound to travel from a ship to the sea floor and back, you can get an idea of how far away the sea floor is. Since this process — known as echosounding — only maps a strip of the sea floor under the ship, the maps it produces often show the path the ship took, hence the “ship tracks.” In this case, the soundings produced by a ship are also about 1% deeper than the data we have in surrounding areas — likely an error — making the tracks stand out more.

Of course, Google are probably just feeding us the line their reptilian overlords want us to hear in order to keep the Secret Mysteries out of the hands of the slave races; the truth is down there, kids. Never stop believing.

[ * – Yes, the Telegraph again. Once the fuss has died down over the initial story, we’ll start getting the human interest pieces about how drug-addicted immigrant Polish ship captains – having successfully abducted Princess Diana and Madeline McCann – are now giving hardworking British taxpayers some form of gay Atlantean cancer.]

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