ESA Selects Targets for Asteroid Deflection Test

Vandil X writes "The European Space Agency has announced that it has selected two candidate asteroid targets for a planned mission to impact an asteroid in an attempt to deflect the asteroid off course by a measurable amount. The mission, dubbed "Don Quijote," will send two spacecraft to their final choice asteroid. One craft will impact the asteroid while the other will observe the asteroid before and after the collision. The mission craft and target selection are expected to be finalized sometime in 2007."

Crash?

[MyLongNickName]

Is this simply a kamikazee run? I did not read anything to make me think otherwise. I seriously question the science of this... being able to calculate the change in direction should only be complicate by not knowing the exact mass of the asteroid.

I would think something like white paint (using the reflective properties to move the asteroid) would be more interesting. Slower, for sure, but much more effective over a period of months or years.

Is there something to this mission that I am missing?

Fighting windmills?

[ReformedExCon]

Surely they should have chosen a name that implied success rather than invoke the name of a hopeless romantic who is known for fighting the inevitable.

And they could have spelled it correctly: Don Quixote.

Hmm... But wait...

[Pichu0102]

...Wouldn't the cost of such a test be well into millions of dollars? That sounds expensive for something that is just a test... But I could be wrong.

Also, never has the quote at the bottom of the screen been so appropriate.

Oh, wow! Look at the moon!

Re:Awesome

[Nefarious Wheel]

True, we didn't change it's course, but if the "object" has been a nuke instead...

It doesn't have to be a nuke. Read "The Moon is a Harsh Mistress" written by an Annapolis grad named Robert Heinlein back in the last century.

"I don't think we should throw any more rocks at Cheyenne Mountain." " -- Why? " "..It isn't there any more."

The grants game

[grozzie2]

This article just goes to show how silly the 'grants game' is when it comes to this type of space mission. The deep impact mission was planned and built when analysis of the rocks was 'in vogue', so it was 'justified' by analyzing ejecta etc from the impact, to determine asteroid composition. Now the ESA boys are contemplating a mission nearly identical, but political times have changed, and 'impacts' is the hot button for getting first priority on grants, so, instead of marking the 'composition analysis' as the primary objective, they mark the 'trajectory change' as the primary objective, and presto, the same mission goes to the top of the heap in the grants pile.

If you think about this even semi rationally, look at the data from the Deep Impact mission. The trajectory of the rock prior to impact was quite well known, well enough, an intercept course could be plotted and executed. Does anybody think that nobody at nasa thought to measure trajectory AFTER the impact, and possibly calculate trajectory changes of the target rock? This is a mission that cost hundreds of millions of dollars, and that's extremely valuable information, available for the taking after the impact. I'm quite sure that while the primary investigators on Deep Impact are all wrapped up in analyzing ejecta data, there are secondary investigators measuring and calculating trajectory changes.

The proposed ESA mission is basically Deep Impact Version 2.0, a more refined variant than version 1. Version 1 (executed by Nasa) intended to hit the target rock, and studying ejecta was labelled as the 'primary' objective. In Version 2, the objective is to hit the target rock much more precisely, relabel the 'primary data' as that of the trajectory change, and re-label the ejecta data as 'secondary'. The end result is, a mission plan that hits more political hot buttons (reference the data collection re-labelling), its easier to get grants for impactor related investigation today.

The reality is, this mission is a logical follow on which builds on the success of Deep Impact. The re-labelling of primary mission goals is just an artifact of the political process required to procure funding, the 'grants game'. The data regarding target object composition will still be collected in various forms, and it'll still get analyzed, just as trajectory data is still being collected and analyzed from the Deep Impact mission.

Should I Worry?

[izomiac]

I'm starting to get worried here. Most of the space programs in the world are trying to hit asteroids, perhaps deflect them. Even the military is now looking at anti-satellite weapons. So I'm beginning to wonder, what's with this sudden surge of interest in defense against things hitting us from space? Do they know something (troubling) that I don't?

Re:Something wrong with p?

[ScriptedReplay]

Good old linear momentum conservation is insufficient information to specify the outcome. Throw in energy balance (assuming you account for all losses of kinetic energy properly) and you have enough information for 1D collisions only - still not enough equations to determine angles; now moving to 'real life' you have to add angular momentum conservation to the mix, too. To completely specify the answer you need details about geometry (mass center, impact point) and surface (orientation, hardness and so on) This already moves the question quite a bit into engineering - and requires data on asteroids. I assume gathering such data is closer to the purpose of this experiment.

Re:Crash?

[MaskedSlacker]

Haha. Fair enough. Nonetheless my point still stands. The balls in a billiards game follow distinct, verifiable, and most importantly predictable rules. Just because you lack the information to make use of those rules, does not mean the balls behave unpredictably.

Re:Crash?

[Fallus Shempus]

Whether it is deflected or absorbed greatly affects the outcome
of the experiment.

Mainly because they need to know how much energy they need
to deflect the asteroid, a deflected explosive may need to
more energetic, where an embeded explosive runs more risk
of breaking it up.
They need to know what will happen.

Re:NO DADDY NO

[Mr. Underbridge]

Maybe, maybe not. That will only work if the entire body is hard and dense throughout. If any of the material is loose or porous, you'll just compress it a bit.

Don't believe what you see in movies.