Space

ESA to test asteroid deflection

ESA to test asteroid deflection
Artist’s concept of the US-European Asteroid Impact and Deflection mission (AIDA)
Artist’s concept of the US-European Asteroid Impact and Deflection mission (AIDA)
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Artist’s concept of the US-European Asteroid Impact and Deflection mission (AIDA)
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Artist’s concept of the US-European Asteroid Impact and Deflection mission (AIDA)
"Energy flash" produced when a projectile launched at speeds up to 17,000 mph (27,000 km/h) strikes a target
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"Energy flash" produced when a projectile launched at speeds up to 17,000 mph (27,000 km/h) strikes a target
Images of the near pass of asteroid Apophis from ESA’s Herschel Space Observatory
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Images of the near pass of asteroid Apophis from ESA’s Herschel Space Observatory
Johns Hopkins' Double Asteroid Redirection Test (DART) spacecraft (Image: Johns Hopkins University)
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Johns Hopkins' Double Asteroid Redirection Test (DART) spacecraft (Image: Johns Hopkins University)
AIDA mission profile (Image: Johns Hopkins University)
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AIDA mission profile (Image: Johns Hopkins University)
ESA's Asteroid Impact Monitor (AIM) craft
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ESA's Asteroid Impact Monitor (AIM) craft
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When you’re trying to keep a rogue asteroid from hitting Earth, you’d better get it right the first time. With this in mind, the European Space Agency (ESA) is looking for new ideas to help develop a US-European asteroid deflection mission. With a target date of October, 2022, the purpose of the mission is to send a pair of spacecraft to a near-Earth asteroid where one will impact it while the other observes the effect.

Dubbed the Asteroid Impact and Deflection mission (AIDA), it's part of ESA’s Space Situational Awareness (SSA) program, which is also seeking ground-based and space-based ideas for ways to study and evaluate how to deflect asteroids.

“AIDA offers a promising platform for the test and demonstration of different deflection methods,” said Detlef Koschny, manager of SSA’s near-Earth object effort. “It is therefore important to ask the users early on what they’d like to do with a mission like this.”

Johns Hopkins' Double Asteroid Redirection Test (DART) spacecraft (Image: Johns Hopkins University)
Johns Hopkins' Double Asteroid Redirection Test (DART) spacecraft (Image: Johns Hopkins University)

AIDA’s purpose is to investigate the physics of high-speed collisions between spacecraft and asteroids. The idea is to send two spacecraft to a binary asteroid. That is, two asteroids where the smaller orbits around the larger. The spacecraft would consist of a Double Asteroid Redirection Test (DART) craft designed by the US Johns Hopkins Applied Physics Laboratory. This carries only an imager for targeting, because its job is to act as a projectile to deflect an asteroid. The second craft is the Asteroid Impact Monitor (AIM) built by ESA. It would survey the asteroid and record events before and after the collision.

“The advantage is that the spacecraft are simple and independent,” says Andy Cheng of Johns Hopkins, leader of the U.S. side of AIDA. “They can both complete their primary investigation without the other one.”

ESA's Asteroid Impact Monitor (AIM) craft
ESA's Asteroid Impact Monitor (AIM) craft

The plan is to target the binary near-Earth asteroids named Didymos. Their collision with DART would be timed to take place when the asteroids are close enough to Earth for easy ground observation, while AIM records the action at the scene. DART would strike the secondary member of the pair, which is 150 meters (492 ft) in diameter. DART is estimated to weigh over 300 kilograms (661 lb) and would be moving at a relative velocity of 6.25 km/sec (13,980 mph, 22,500 km/h).

At that speed, the collision would be an example of “hypervelocity impact.” DART would hit the asteroid so hard that the materials at the impact point would turn into plasma. That’s a very hard hit, but the question remains ... how much would an asteroid be deflected by such a collision? For this reason, the AIDA team have chosen a binary asteroid pair, which makes the deflection easier to measure and evaluate because of the weaker gravitational forces involved. The hope is to deflect the target by 0.5 to 1 percent.

ESA says that the AIDA project has other uses than asteroid deflection. It can also give insights into the history of the early Solar System, and the threat posed by space debris.

Sources: ESA, EPSC Absracts (PDF)

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9 comments
9 comments
RCMining
It looks from the photo they hope to smack it with a big solar panel.
Let's hope the observer satellite doesn't relay, "Oh crap we just set it on a collision course with the Earth!"
Derek Howe
Don't worry RCMining - Drilling technology keeps improving & we still have Bruce Willis! and he has Never, NEVER missed a depth that he has aimed for!
zevulon
they should nuke a 300 meter asteroid with a 5megaton nuke with a bunker buster self burying design that is directed at the midpoint of the asteroid at a speed of 4km/sec -----and just see what happens when the nuke explodes.
this is probably the simplest and most useful exercise is proving or disproving the utility of a nuke. you figure a bunker buster is going to get at least 10meters, or quite a bit more through the surface of an asteroid, which is probably a lot less dense than reinforced bunker concrete shell material.
when the nuke explodes you get a chance to see what 5 megatons will do from just under the skin of a 100 meter beast.
why do i say 100 meter? there are A LOT OF THEM OUT THERE. and an asteroid that big is likely to be seriously affected by a nuke, much bigger, and probably not, much smaller and probably no point.
there is a HUGE X factor of how nukes will affect asteroids that we don't understand yet and people think it's just like on earth, when it's not. we are accustomed to understanding nukes through their interaction with the atmosphere, or through their interaction with the earth, when they are tested underground. a few nukes have been tested in the oceans and even fewer in space. BUT NO nukes have been tested in an underground mass with NO air above the underground mass. this is essentially what testing a nuke in an asteroid would be like , and we really have no analogues for this. we need to do it directly to see what would happen. the reaction of the asteroid might be unique to the composition and consistency, as well as the spin of the asteroid. imagine a huge amount of heat being dumped into the asteroid. the asteroid composition would determine how the heat was dealt with to an extent, there are no currents of air to convect away heat from the asteroid, so the heat of the nuke may itself linger and continue to influence the motion and spin of the asteroid for a long duration after the initial blast.
perhaps the best reason to abandon the plan to nuke an asteroid is that all asteroids are slightly different and for this reason no single nuclear experiment on one stroid can be used for projecting the results on another.
Slowburn
re; RCMining
The asteroid can not under any circumstance be accelerated towards the point of impact. The people doing this are concerned about future meteor impacts and of above average intelligence. The one outcome that will not happen is the rock being put onto a collision course with earth.
re; zevulon
For deflecting interplanetary masses on a impact course with earth the fine details of how the nuclear explosion and the mass interact is not important. A comet suffer a lot more vaporization than a stony or metallic mass and it will no longer present a danger to earth as that any solid remains will be either too small to cause a problem or accelerated onto a different course so as to miss the earth. A stony or metallic mass will have much less vaporization but if you assume that you will get no vaporization of the asteroid mass and affect the velocity change that will generate a minimal miss with the vaporization of the mass of the nuke alone any additional vaporization of the asteroid mass will just increase the amount of change on the mass's course. Any and all fragments generated are far less dangerous than the parent mass was.
Nukes are the most energy dense devices we currently know how to make and it is important to deliver the energy at the time and place that it can make the change in velocity that will generate a miss.
John Hogan
@Zevulon...
1. Cool name! I sometimes use Spankulon :-)
2. I'm wondering if the nuke option might need either a slower closing speed or some proximity fuse? 6km per sec is slower than electricity but could be faster than the chemical reaction of the detonation explosives that set off the nuke. Maybe the idiot proof way could be a "Little Boy" type bomb that uses a carefully controlled impact speed as part of the mechanism? hmmm I really don't know what I'm talking about.
notarichman
at zevulon; i believe there is an international treaty prohibiting the testing of nukes in space. the treaty would have to allow the testing for the benefit of all and probably would have to involve all the treaty nations.\
if scientists can not predict the effect of impacts in space on objects; then how do they expect to predict where this asteroid will go after the impact? i.e. how will they know that the asteroid will not hit earth?
i suppose they can make an estimate of the asteroid's mass by volume, but how will they know it's content? nickel / cobalt / iron asteroids must mass more than the other type and the article doesn't say they plan on investigating the asteroid's type before impact.
Slowburn
re; notarichman
The limited nuclear weapon test ban treaty does not mention engineering tests such as asteroid deflection of for that matter war shots. The Comprehensive Nuclear-Test-Ban Treaty that has not come into effect bans all use of nuclear explosives which puts it into the running for the most silly treaty of all times award.
Kwazai
They want a 'one shot' device. sounds counterproductive. I'd be thinking a 'slingshot cannon'(magnetic?) on the moon- liking playing with a trebuchet?
Slowburn
re; Kwazai
If you were to build a large steerable gun on the moon to fire ultra-velocity projectiles for meteor deflection multiple shot capability is a given but on a vehicle that will only be in the right place once a single shot accelerator is all you need.