The Swarm Constellation Will Look Inside the Earth

Roland Piquepaille writes "Among six Earth Explorer candidate missions, the European Space Agency (ESA) has chosen a 'Swarm' of satellites to look inside the Earth and to do the best survey ever of the Earth's geomagnetic field. The mission, scheduled for launch in 2009, will consist of three satellites released by a single rocket. Two will fly side-by-side 450 km above us while the third one will cruise at an altitude of 530 km. In "ESA to probe Earth's magnetic field," the Register also looks at this future mission which will lead to a better analysis of the Sun's influence in our solar system. More details and illustrations are available in this overview."

Comments

what's going on here?

[Anonymous Coward]

has slashdot's magnetic polarization pushed all the comment posters away from this story?

Re:what's going on here?

[cazzazullu]

Na we are just not interested in a "swarm" of three sattelites ;)

Re:what's going on here?

[justkarl]

Na we are just not interested in a "swarm" of three sattelites ;)

I dunno, is a "swarm" the same as a beowolf cluster?

2009?

[pu'u_bear]

I just hope there is still a magnetic field by then...

If for no other reason

[Discoflamingo13]

it would be nice to see a system with the ability to update a magnetic variation map of the world faster than NOAA (which happens about every 5 years). Most avionics navigation systems are dependent on these maps for accurate magnetic heading information, and few companies have the resources to make updates between NOAA passes. Depending on its accuracy, it could pay for itself very quickly, if it could make such maps.

Re:If for no other reason

[Anonymous Coward]

I'm a geophysist, not a pilot. We normally use IGRF. It has the history of the magnetic field as well as future predictions. It's very accurate and is updates at every five years. That sounds the same as what you are talking about, but you can make a new map every year that's much more accurate than last years, even without a new model. The drift of the field isn't random.

Pilots only need a very gross measurement of magnetic field. They really only care about the field coming from the earth's core. We measure the field coming from the core and the rocks then remove the core's field. The field from the rocks is much smaller, but can tell you a lot.

Re:If for no other reason

[Anonymous Coward]

If and only if GPS doesnt completely rule out magnetic navigation.

Re:If for no other reason

[Discoflamingo13]

For civilian applications (which lack military precision), and in the event of GPS failure, magnetic heading will always be there to fall back on.

Re:If for no other reason

[Discoflamingo13]

Magnetic headings are usually the first fallback during severe weather conditions, and avionics companies want the maps of the variations to be as accurate as possible. For verification purposes, most companies won't rely on predictions (regardless of how accurate they most certainly are) - they want to see hard measurements based on the most current data. This is largely because these decision are made by businesses, and not science firms - but it doesn't make your point any less valid.

Re:If for no other reason

[bravehamster]

magnetic heading will always be there to fall back on.

Not always, no. We're overdue for a flip in the magnetic poles. The flip itself won't happen instantaneously, and during that period there will be a lot of weird currents and local poles that would shift constantly. Magnetic heading would change drastically, possibly from day to day.

Re:If for no other reason

[Discoflamingo13]

Chances are more than likely that during this time, planes will be grounded until the weather is clear for the duration of the flight. New magnetic variation maps are drawn once the field stabilizes, and aviation goes on. Planes in communication with a control tower can manually enter a makeshift heading - this happens during some heavy electrical storms, or when the magnets fail. The problem is flight over unpopulated areas (like the ocean).

Re:If for no other reason

[Andy Mitchell]

Does anyone know if the magnetic poles shift without the field significantly weakening?

As I recall life on the planet earth depends on the van allen radiation belt, and that needs the magnetic field and the solar wind to exist.

Re:If for no other reason

[Elendur]

The field just about goes away. There was a Slashdot article on this at some point in the last few weeks, search for it. It was pretty interesting.

Reminded me of...

[krjordan]

... Crichton's book Prey, which had a similar discussion of swarming optics. Then the little buggers all turned on the humans and death ensued. That could never happen, right?

Oh No!

[wan-fu]

But in the midst of probing the geomagnetic field, the satellites will accidentally cause our Earth's core to stop spinning. This will undoubtedly cause mass chaos in the world. As a result, we will require the services of a geophysicists and a gung-ho team of scientific explorers who will risk their necks by attempting to detonate a nuclear device in order to jump start the core and get it spinning again. Wow, this would be a great plot for a movie... wait... nevermind.

Earth's magnetic field is starting to flip?

[garyebickford]

Some scientists think the Earth's magnetic field is preparing to flip again, which it does every so often. Apparently when this occurs, it is preceded by a period of local variations - mini-poles showing up all over the planet. This system could be invaluable in tracking this process.

Also, according to this article and others, the field has decreased 10% over the last 150 years. This has left some satellites vulnerable to damaging radiation.

Other links:
Sun's rays to roast Earth as poles flip"
The Sun Does a Flip
Quick flip of Earth's magnetic field revealed

Very unlikely

[poptones]

We can put a mach5 missile down the chimney of a house using GPS; I'm sure commercial aircraft would be able to navigate just fine even if there were zero magnetic field.

Re:Very unlikely

[Mycroft_VIII]

We can't do that reliably, or even most of the time.
While GPS itself (if you have the military's descramble key for the extra accuracy) is on that order of accuracy, the missles themselves are not quite that good.
Still Once in a while a missle does pull off a cool stunt like that and eigther it has a nose camera sending back info or some other camera catches it.
Where feasable the military likes to show THOSE pics off as they have great PR and propaganda value. After all would you like to face an enemy that apears to be able to pick off just one person in a hotub out of five from 200 miles away with a cruise missle?
That said your basic point is sound. Even without mill-spec decode of the signals you still have enough accuracy to get with visual range of an airport, and even before then stay on a good course and be in a towers airspace for thier assistance as well.

Mycroft

Re:Very unlikely

[wideBlueSkies]

>>After all would you like to face an enemy that apears to be able to pick off just one person in a hotub out of five from 200 miles away with a cruise missle?

I wish I had mod points today bro. That's the best laugh I've had in about a week. :)

Peace.
wbs.

Re:Very unlikely

[Mycroft_VIII]

Thank you.
When looking for an example (hyperbolic preferably) I just had this sudden image of a bunch people like bin laden and some evil ninja dudes with the expected prostitute types and some ceo type all in a hot-tub when a missle slams into just one and everyone else giving each other "holly $#IT, What the F~(K was that" looks followed by much running and screaming.
Good sig too. The proffesor was alot wiser than the image of that stereo type that is often pined on him.

Mycroft