NASA's DART asteroid smash flung 2 million pounds of rock into space

[Admin]

The massive tail created by the collision of a spacecraft and an asteroid earlier this year is unlocking key information about space rocks and how to respond if an asteroid ever threatens Earth.

NASA's DART asteroid smash flung 2 million pounds of rock into space : Read more

 

[Vernon Brechin]

Once the research has refined the impact effects then serious consideration should be made of utilizing a small portion of the current and retired fleet of U.S. ICBMs to deflect threatening incoming space bodies. I think that would make a better use of their massive thermonuclear warheads.

 

[Unclear Engineer]

The problems with that are (1), it is not clear that a nuclear explosion is going to have the desired effect on an asteroid - it might turn it into a swarm of impactors instead of just deflecting it away from impact, and (2) the ICBM rockets are not able to deliver their warheads to that distance in space - they are intended to loft them hundreds of miles above the surface at sub-orbital velocities. Some could achieve low-earth orbit, but not escape velocity with the payloads they carry.

Yes, parts of ICBMs could be repurposed and used.

 

[Vernon Brechin]

The problems with that are (1), it is not clear that a nuclear explosion is going to have the desired effect on an asteroid - it might turn it into a swarm of impactors instead of just deflecting it away from impact, and (2) the ICBM rockets are not able to deliver their warheads to that distance in space - they are intended to loft them hundreds of miles above the surface at sub-orbital velocities. Some could achieve low-earth orbit, but not escape velocity with the payloads they carry.

Yes, parts of ICBMs could be repurposed and used.

Thank you for your well considered input. I agree that they are not now configured to make such a trip and that many unknowns exist regarding hitting them with a massively high nuclear yield detonation on their surface. I have assumed that many of the current on-alert ICBMs contain multiple independently targeted thermonuclear warheads.

I assumed that they could be reconfigured by eliminating all but one of the warheads, a smaller, lighter reduced yield warhead could be substituted, or that a inertial impactor with terminal guidance would be employed under the nose cone.

 

[Unclear Engineer]

Vernon, That is one of the strategies being researched. It is just not a simple thing of aiming existing ICBMs at asteroids. The rocket vehicles need to be configured to achieve the necessary solar transfer orbits, and the warhead yields may need to be adjusted to suit the mass and cohesiveness of whatever asteroid would be the target.

 

[Vernon Brechin]

Vernon, That is one of the strategies being researched. It is just not a simple thing of aiming existing ICBMs at asteroids. The rocket vehicles need to be configured to achieve the necessary solar transfer orbits, and the warhead yields may need to be adjusted to suit the mass and cohesiveness of whatever asteroid would be the target.

Thank you for letting me know the strategy is being considered. My view has been that the existing ICBM fleet control centers, or an entity further up in the command, has the capability to substantially, within limits, retarget the missiles and also adjust many of the thermonuclear warhead detonation yield parameters and that it is done remotely within a short period of time.

 

[Unclear Engineer]

I think you are probably correct about the targeting of ICBMs, but not sure that warhead yield is very adjustable.

That said, I think the technology for having a rapid launch capability for an asteroid intercept mission is entirely feasible to establish with today's technology. We just need to put the hardware together and test it, so that, like the ICBMs, we can launch quickly when a threat is detected.

The warhead, or impactor, or whatever deflection method will be employed, is another matter. We really don't know enough about asteroids, and the variability of the asteroids, to know what we want to do to change the orbital trajectorie of any particular one. And, then there are comets, too. We may need a variety of things for the payload of our asteroid/comet defense system missiles.

The DART mission was calculated to alter the target's velocity by a certain amount assuming that the impactor just had its momentum absorbed by the target. But, it looks like what happened is that the kinetic energy of the impactor created a crater and threw the material that had been in it directly back along the impactor's trajectory, creating a thrust that also slowed the target's velocity. And, that thrust momentum effect from the ejected asteroid material was more than twice the effect of the impact momentum. So, perhaps an explosion of the right magnitude couid be more effective than just hitting the target with a heavy object. But, we need to be careful to not blow the target apart and create a swarm of pieces that could still hit Earth as large enough chunks to cause extreme damage.

Knowing what level of explosion will work best will probably require us to learn a lot more about both comets and asteroids, so that we have some idea what the target will be like if we find one headed for us that we failed to detect years ahead of impact, so that we could study it in detail before deflecting it. That secenario is always going to be a possiblity, because things in the Kuiper Belt, Oort Cloud, or interstellar space can potentially enter the inner solar system at any time with no advanced warning.

 

[Vernon Brechin]

I think you are probably correct about the targeting of ICBMs, but not sure that warhead yield is very adjustable.

That said, I think the technology for having a rapid launch capability for an asteroid intercept mission is entirely feasible to establish with today's technology. We just need to put the hardware together and test it, so that, like the ICBMs, we can launch quickly when a threat is detected.

The warhead, or impactor, or whatever deflection method will be employed, is another matter. We really don't know enough about asteroids, and the variability of the asteroids, to know what we want to do to change the orbital trajectorie of any particular one. And, then there are comets, too. We may need a variety of things for the payload of our asteroid/comet defense system missiles.

The DART mission was calculated to alter the target's velocity by a certain amount assuming that the impactor just had its momentum absorbed by the target. But, it looks like what happened is that the kinetic energy of the impactor created a crater and threw the material that had been in it directly back along the impactor's trajectory, creating a thrust that also slowed the target's velocity. And, that thrust momentum effect from the ejected asteroid material was more than twice the effect of the impact momentum. So, perhaps an explosion of the right magnitude couid be more effective than just hitting the target with a heavy object. But, we need to be careful to not blow the target apart and create a swarm of pieces that could still hit Earth as large enough chunks to cause extreme damage.

Knowing what level of explosion will work best will probably require us to learn a lot more about both comets and asteroids, so that we have some idea what the target will be like if we find one headed for us that we failed to detect years ahead of impact, so that we could study it in detail before deflecting it. That secenario is always going to be a possiblity, because things in the Kuiper Belt, Oort Cloud, or interstellar space can potentially enter the inner solar system at any time with no advanced warning.

Your analysis and suggestions are good. I agree more preliminary research is needed to refine the best approach.