NASA May Use Nukes To Defend Earth From Asteroids

Popular Science ^ | 06-22-2015 | By Sarah Fecht

[BitWielder1]

Depends on when the nudge is applied.
The longer we wait, the more correct you would be.
If we encounter a killer asteroid in this century, I could not help but think there was a reason God let us invent the atomic bomb and space flight just about now.

[Old Sarge]

I had this discussion with a few fellow eggheads not long past, and it went something like this:

Let's start with the idea that we can eliminate an inbound impactor, or at the least alter its trajectory.

Destruction would require a massive thermonuclear payload, or multiple payloads with a precision deployment - more firepower than is available. Destruction: OUT.

Turning to deflection, the key is finding the Intercept Point (IP) where the force applied would cause the trajectory to change just enough to either miss the planet, or skim the atmosphere to either break up or mitigate the impact.

The IP has to be far enough out where available weaponry can make the required course change. And there's problem: we don't have that many launch vehicles to get the payloads there.

Most ICBMs are suborbital boosters, meant to get their payloads in low orbit, then gravity takes over and they reach their targets. Therefore, using Titans or SS-23's would mean the IP has to be in Earth orbit - most likely not getting an IP that would achieve the result.

If a more distant IP is needed, then the only boosters capable of the task would be Delta-3 rockets or Energiya's, if operational. Even then, the IP would be in near geosynchronous orbit (approx. 25K miles) - and that's cutting it close.

Targeting the inbound itself would not be difficult - the missiles could be radar-guided to IP, or the IP calculated into the guidance package.

And then, there's the golden problem: DETECTION: All of these schemes will work, ONLY IF the impactor was detected out far enough for the boosters to be readied, the payloads loaded, the targeting systems aligned, and THEN comes the risks of success - even IF the impactor is neutralized, we still have meteorrites raining down on the planet, PLUS the EMP generated from detonating multiple weapons in Earth orbit.

An interesting exercise.

[Red Badger]

We could not get a missile off in time to deflect/destroy much of anything in the time necessary, probably even if we had them already in orbit just waiting for the ‘go’ signal...........................

[Gandalf_The_Gray]

Turning a few small rocks into a bunch of little bitty rocks.

Large rock is following a trajectory defined by gravity.

Bomb smashes rock to iddy bitty pieces.

Pieces continue to follow former trajectory as a spreading "cloud" of rubble.

Earth get hit by a "shotgun" blast.

Better idea to change trajectory and steer rock away from Earth orbital path.

Regards,
GtG

[Old Sarge]

Two incidents come to mind, recently...

First the Chelabinsk fireball from 2013 - NONE of the self-proclaimed astronomy experts saw it until it hit the atmosphere.

Second, a rock came down in the Sudan recently, and the same people were high-fiveing each other because they actually detected the inbound - NINETEEN HOURS before it hit.

Doesn’t lend much credence to the idea of “THERE’S NOTHING OUT THERE, YOU’RE STUPID!!!”

Because... how would they know?

[LucyT]

NASA May Use Nukes To Defend Earth From Asteroids

Check out # 45 , and # 42 .

Thanks, Old Sarge. Interesting...

[TheOldLady]

Yes. They’re called the Religion of Pieces... Heads, hands, feet, etc., etc...

[Redcitizen]