Chelyabinsk asteroid fireball

NASA Scientists Present Asteroid Deflection Research

Guest essay by Eric Worrall

NASA Scientists performing experiments on actual Asteroid fragments have presented conclusions about the limits of inbound Asteroid deflection, and the need to plan for multiple “bumps” if the Asteroid is made of an unfavourable material.

Deflecting an Asteroid Before It Hits Earth May Take Multiple Bumps

After years of shooting meteorites with a special gun owned by NASA, researchers highlighted challenges for a preferred method of planetary defense.

By Katherine Kornei
Aug. 25, 2021

There’s probably a large space rock out there, somewhere, that has Earth in its cross hairs. Scientists have in fact spotted one candidate — Bennu, which has a small chance of banging into our planet in the year 2182. But whether it’s Bennu or another asteroid, the question will be how to avoid a very unwelcome cosmic rendezvous.

For almost 20 years, a team of researchers has been preparing for such a scenario. Using a specially designed gun, they’ve repeatedly fired projectiles at meteorites and measured how the space rocks recoiled and, in some cases, shattered. These observations shed light on how an asteroid might respond to a high-velocity impact intended to deflect it away from Earth.

At the 84th annual meeting of the Meteoritical Society held in Chicago this month, researchers presented findings from all of that high-powered marksmanship. Their results suggest that whether we’re able to knock an asteroid away from our planet could depend on what kind of space rock we’re faced with, and how many times we hit it.

Read more:

The research paper is below (original source here).

It is nice to see NASA scientists getting their hands dirty, performing physical experiments, rather than just spinning up a bunch of models.

Although the risk of an Earth impactor which causes more than localised damage is extremely low, a large impact could have severe consequences, causing widespread disruption to food chains or worse.

I would personally like to see the Project Orion research programme restarted.

Project Orion was one of the most powerful space drives ever conceived, a method of propelling a space ship using nuclear explosions. The most powerful version could have been used to send a 100 year manned mission to Proxima Centauri, at around 3% of the speed of light – a slow journey, but not inconceivable.

For a while Orion was a serious contender for the Apollo missions, until politicians chickened out, and chemical powered Saturn rockets were chosen. An Orion powered Apollo mission would have included a tour of the inner solar system, with landings on the Moon and Mars, and a visit to Venus.

So plenty of power for carrying space cannons or whatever to any corner of the solar system, all buildable using 1950s technology.

Freeman Dyson, one of the principals of the Orion Project, was confident it was worth a try, based on actual physical tests using nuclear explosions, but he had lingering concerns about accelerated erosion of the centre of the pusher plate, due to turbulence in the nuclear bomb blast – a concern which would have required a full scale physical test of a minimum size Orion spaceship to settle.

Obviously nobody wants a return to regular atmospheric nuclear tests. But surely after all the tests in the 1950s, we could stand to have a few atmospheric detonations in some remote part of the Pacific Ocean, just to see if this potential planet saver works, before we have to scramble to try to build it for real. A single Orion launch would release far less radiation into the Pacific Ocean than the Fukushima meltdown, and such a launch would provide inestimable value in terms of developing planetary Asteroid defence capabilities.

Video – meteor striking in Lapland.

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August 30, 2021 10:17 am

Orion is much too practical.
Besides, the green blob would create a need for a superlative of melting down, which would surely be their reaction.

Reply to  Tom Halla
August 30, 2021 12:20 pm

Need to use renewable energy to do it. And there just isn’t enough. Batteries can’t lift themselves into orbit. We’re doomed!

Reply to  Brian R Catt
August 31, 2021 12:52 pm

Maybe an electric satellite can get a boost from an electric airplane…. 😉

August 30, 2021 10:31 am

Aiming a high output LASER for several years would also slightly deflect the asteroid/comet if done while far away. Whether that is solar powered lasers or nuclear powered lasers probably doesn’t matter on the source, as long as one could bombard the object with enough high energy photons, enough to make it off gas and slowly deflect it a small tiny amount, enough to miss the good Earth if caught in time. This will be a thing some day, and maybe one of the most important reasons in the scheme of things why we evolved to go all the way to space.

Reply to  Earthling2
August 30, 2021 12:22 pm

Solar power lasers would keep going out if the Earth is still rotating, only useful at lunchtime, if the Sun is shining.

Randle Dewees
Reply to  Brian R Catt
August 30, 2021 12:59 pm

Don’t know if you are being a bit sarcastic but the lasers would be spaced based – that creates problems but solves some intractable atmospheric issues.

Reply to  Randle Dewees
August 30, 2021 1:42 pm

I had thought that would be self evident, that they would be space based lasers, powered either by nuclear or solar. Some space based solar makes sense where it could get 24/7 full sunlight free of the atmosphere.

Reply to  Earthling2
August 30, 2021 8:12 pm

…and where it could be used for weapons.

Reply to  jorgekafkazar
August 30, 2021 9:47 pm

China is already working on that. No worries. Oh, maybe we should worry.

oeman 50
Reply to  Earthling2
August 31, 2021 5:42 am

Is your real name Crazy Eddie?

Reply to  oeman 50
August 31, 2021 12:59 pm

And is he from Mote Prime?

Gordon A. Dressler
Reply to  Earthling2
August 31, 2021 7:50 am

Asteroids or comets of the size we might hope to deflect with lasers would be of an average diameter of 10 km or less. For reference, the Chicxulub impactor had an estimated diameter of 11–81 km (6.8–50.3 mi).

For a diffraction-limited Gaussian laser beam having perfect beam quality, the e^-2 beam divergence half-angle is λ / (π * w0), where λ is the wavelength (in the medium) and w0 the beam radius at the beam waist (minimum width point, usually just the laser output aperture width). 

As an example, a 1064-nm beam from a Nd:YAG laser with perfect beam quality and a beam radius of 1 mm in the focus has a half-angle divergence of only 0.34 mrad = 0.019°.

Assuming technology we have not yet demonstrated, let’s generously assume that Earthlings can design a multiple-terrawatt, space-based, solar energy sustained, continuously operating free-electron laser operating at about 0.4 μm wavelength (~ the highest frequency that we can be confident will be mostly absorbed by the surface of an asteroid) and providing a perfect-quality beam that is 1 m in diameter (500 mm in radius) and that it, in turn, goes through a beam tracking-pointing mirror assembly with zero distortion. By the above equation, the beam divergence half-angle will be about 8.3E-7 rad (5E-5 degrees).

If we needed to start trying to deflect an asteroid or comet using the above hypothetical super duper laser at a distance of only 1 AU (and that’s really close-in in terms of their orbital dimensions relative to Earth), the unavoidable beam divergence alone would result in the laser energy being spread over a circular area that is ~250 km (~160 miles) in diameter at that distance. With a target having only ~10 km diameter, the power delivered onto the target in this scenario would be only (10/250)^2 = 0.16% of that output by the laser, even assuming a zero albedo (i.e., total absorptance).

Of course, objects smaller than 10 km diameter would be absorbing even less beam power.

Therefore, the fundamental physics of diffraction-originated beam divergence of laser beams show that laser deflection of asteroids/comets is just not practical, even with imagined future technology.

Reply to  Gordon A. Dressler
August 31, 2021 10:21 am

I think you missed the point with assuming we would be operating and aiming the Laser from 1 AU. You would get the laser within a few miles of the asteroid and heat the asteroid with the laser until the outgassing was enough for the outgassing of the material to apply the thrust to begin slowly changing the trajectory. If you are past the Martian orbit, solar would be a poor choice and a nuclear operated laser would be the only option. Much like detonating an nuclear bomb a few tens of miles away from an asteroid to change its trajectory with the shock wave, not detonating the nuclear bomb 93,000,000 miles away from said asteroid.

Gordon A. Dressler
Reply to  Earthling2
August 31, 2021 2:52 pm

“You would get the laser within a few miles of the asteroid.”

Do you have any idea of the propulsive energy required to not only get such a postulated high power laser assembly to the distance of an asteroid that is “several years” from impacting Earth but doing a rendezvous with matching Sun orbital ephemeris as to stay “within a few miles” forward of the asteroid (or comet) path so as to maintain laser heating on the face aligned to the velocity vector?

Of course, there would be problems, wouldn’t there, in heating and outgassing the object’s surface in a favored direction if the asteroid happened to rotating on an axis not aligned to the orbital velocity vector (a very common occurrence).

Finally, I do believe the largest single nuclear reactor today produces about 1.75 GWe, about 0.2% that needed for a 1 TW free-electron laser beam, assuming 100% efficient power conversion. What’s your mass estimated for such a nuclear reactor designed to operate in the vacuum of space?

Reply to  Gordon A. Dressler
September 1, 2021 7:22 am

Who knows what the future holds for technology, but in 50 years from now, things will become apparent what would be the best method to nudge an asteroid a fraction of a degree 200 million miles away, and the asteroid misses the good Earth by a small amount, enough to avoid immediate catastrophe. This is why is is healthy to discuss and debate any all methods to sort out what direction we take.

Laser deflection isn’t my idea…has been around for decades in science fiction and just relies on heating a small amount of the asteroid surface to seriously outgas at that point to provide a small of thrust to slightly change course. Rotation shouldn’t be a deal breaker…it will continually outgas from the same direction while the asteroid tumbles through space. There are details for sure, the basic calculations, such as what you provide.

You could also park a 100 ton object within a few Km or so of the object, and use it as a gravity tractor to also slowly change course a very slight amount using the law of gravity (attraction) with the manmade object slightly tugging on it for a few years to take it off course fraction of a degree to miss the planet. Or a solar sail…or a series of directional nuclear blasts from a few Km so as not to shatter it to pieces. Many asteroids are already just rubble piles bound together weakly by gravity.

We have landed a 1/2 ton satellite on an asteroid 100 million+ miles away already, so imagine what we will be able to do in 50 years. Early detection is the key, and the ability to mobilize something to that spot way off yonder, while we could give it a nudge one way or the other makes sense for us Earthlings to ensure we don’t wake up some day to find out we have an incoming in 5-10 years and too late to do anything.

Gordon A. Dressler
Reply to  Earthling2
September 1, 2021 11:20 am

We have landed a 1/2 ton satellite on an asteroid 100 million+ miles away already, so imagine what we will be able to do in 50 years. 

Well, the launch vehicle with the largest capability to deliver mass into Earth orbit (and thus beyond) was the Saturn V, that was operational from 1967 to 1973 . . . that is, was in use starting 54 years ago.

As of today, the Saturn V remains the most powerful (highest total impulse) rocket ever brought to operational status, and it holds records for the heaviest payload launched and largest payload capacity to low Earth orbit (LEO) of 310,000 lb (140,000 kg), which included the third stage and unburned propellant needed to send the Apollo command and service module and Lunar Module to the Moon.” ( )

Based on these facts, I imagine very little, if any, technical progress will occur in the next 50 years with respect to mankind’s ability to launch massive payloads to orbit or to rendezvous with solar system objects using any new launch vehicle.

Reply to  Gordon A. Dressler
September 1, 2021 4:25 pm

Respectfully disagree. The shuttle stack was capable of putting around 150 tons (300+k#) into LEO. Here’s how you do the math:

Orbiter – around 200k
Payload – around 50 k
ET – 65k
Ullage (unused propellant) – 5 – 10k

It was a pretty good stack, especially the SSMEs. We could have done a lot more with it than we did. Cheers –

Gordon A. Dressler
Reply to  agimarc
September 1, 2021 6:00 pm

Please inform Wikipedia of this needed correction. 🙂

Cheers back at ya.

Gordon A. Dressler
Reply to  agimarc
September 2, 2021 7:57 am

To specifically point out your accounting error, the STS Orbiter with its SSMEs was consider part of the launch system and NOT part of the payload.

By your own accounting delineation, the payload to LEO of the Shuttle “stack” was ~50 Klbf . . . this compares to the S-V payload to LEO of 310,000 lbf.

michael hart
Reply to  Earthling2
September 1, 2021 3:48 pm

“Early detection is the key, and the ability to mobilize something to that spot way off yonder, while we could give it a nudge one way or the other makes sense for us Earthlings to ensure we don’t wake up some day to find out we have an incoming in 5-10 years and too late to do anything.”

I guess one could just go short on every stock in the DJI and enjoy 10 years of fabulous wealth. 🙂

More seriously, I am looking forward to some general reappraisal on the likely causes of the Younger Dryas being related to a cometary impact only ~12,800 years ago. If it proves to be correct, then humanity really does have something to worry about in the medium-term.

Reply to  Gordon A. Dressler
August 31, 2021 3:54 pm

It would be much simpler to use a number of small nuclear charges. The radiation would vaporize the surface layer of the asteroid and the recoil would change the orbit of the asteroid slightly.

It is possible to build nuclear weapons that radiate most of their energy in two relatively narrow cones. How to do this was figured out by Freeman Dyson as part of the Orion ptoject.

Gordon A. Dressler
Reply to  tty
August 31, 2021 5:33 pm

Sorry, I am not the person arguing for laser deflection of asteroids.

Reply to  Gordon A. Dressler
September 1, 2021 4:49 am

Yes, you are absolutely right. This is an important additional argument that the laser approaches (Dr. Lubin’s DE-STAR and so on) are the science fictions. This is why I tried to suggest an improved solar-concentrating method – see the relevant section in the Wikipedia (“Asteroid impact avoidance – Use of focused solar energy”.

Reply to  Earthling2
August 31, 2021 9:20 am

Laser asteroid deflection this is science fiction. If a powerful continuous-wave laser is placed on the ground, then, as has long been proven experimentally, its beam will not be able to overcome the atmosphere without dramatic distortions. If it is placed in open space, it will quickly be damaged, since there are no methods for cooling it sufficiently.

Reply to  Viktor
August 31, 2021 12:20 pm

ALL asteroid deflection at this point in time is science fiction. I am sure there are engineers capable of providing shading to such a laser in space, and provide the coldness of space to cool the laser. As they already do with other sensitive satellites to shade the satellite from direct sunlight, and then have the vacuum of space and the perpetual cold in the shade of the Sun. The solar radiation heats the space near Earth to 393.15 K (120 degrees Celsius or 248 degrees Fahrenheit) or higher, while shaded objects plummet to temperatures lower than 173.5 K (minus 100 degrees Celsius or minus 148 degrees Fahrenheit)

The military of several countries are already developing space based lasers, so this has probably been thought though. I am not advocating for ground based lasers to deflect an asteroid 100 million miles away either. You would need to get that laser within a few miles of the asteroid to heat the ice or rock to vaporize and become a source of thrust from the outgassing. The Sun already does this with photons/heat. This is the tail we see on comets when getting close to the Sun.

Work has already been done with ground based lasers to affect satellites as part of spaced based military operations. Probably to burn a hole in their propellant tanks, and/or affect or disable their lensing cameras.

Reply to  Earthling2
September 1, 2021 3:53 am

My comment was about the impossibility of dissipation the heat generated during the operation of the powerful continuous-wave (this is the key point) laser, but not about “shading to such a laser”, which practically does not matter. 

August 30, 2021 10:32 am

Chelyabinsk. Comes out of nowhere, blows off layers and shatters buildings and glass windows in its progress through the atmosphere, then the last layer is blown off and it’s just a big rock from outer space.

Well, if we’re gonna do this, we’d better get on it because there’s lotsa rubble out there in the solar system, never mind what’s in the Vulcanoid zone, that is looking for that special moment.

For some reason, I kept reading “ORION” as “ONION”. Must be too close to lunch time. My bad.

Just in case anyone is wondering, I did ask my insurance agent if my HO coverage includes meteor strikes on my small and humble castle, and unfortunately, it does not. So I got umbrella liability as a precaution – just in case.

Reply to  Sara
August 30, 2021 3:07 pm

In case anyone was asleep long enough to miss all kerfuffle here is reminder:

Reply to  Sara
August 31, 2021 7:03 am

That covers umbrellas?

B Clarke
August 30, 2021 11:03 am

Heres some footage of project orion with test models,

Joao Martins
August 30, 2021 11:12 am

If it works as well as NASA’s climate predictions guesswork, our only hope relies on the very low frequency of immediate contacts of big asteroids with our planet…

Bruce Cobb
August 30, 2021 11:15 am

It is not considered either sportsmanlike or indeed of much use to shoot at a meteorite since, after all, it is just lying there on the ground, smoldering. Sheesh.

Zig Zag Wanderer
Reply to  Bruce Cobb
August 30, 2021 2:43 pm

Except in Texas

Julian Flood
August 30, 2021 11:27 am

I had fun with the incoming asteroid problem in a short story I never sold entitled Hittile. Nuke pulse first stage, steam rocket to slow down after impact, laser sail to get back to Earth. I postulated an Earth defence (OK, defense) system called Hoplite in orbit and on watch. If only we had politicians who realised that a big impact would dwarf all other problems we face as a species.

(Three collections of short stories on Amazon. I couldn’t put up the one I sold to Analog because I’m not sure of the copyright, but about ten of them were good enough to sell to SF magazines. Lucifer Falling should really be a video.)

Ron Long
August 30, 2021 11:53 am

Speaking for dinosaurs everywhere, this idea of deflecting an asteroid is more important than you can imagine. Just Saying.

Reply to  Ron Long
August 30, 2021 12:42 pm

Yeah, but Ron Long, there are billions of them out there in the solar system, never mind in the Oort Cloud, and yet the probability of Earth getting pounded by a swarm of them. is lower than you buying a winning lottery ticket.

Ron Long
Reply to  Sara
August 30, 2021 1:33 pm

Sara, find a dinosaur and ask them about the issue. Since I don’t buy lottery tickets the chance is even lower than you can imagine.

Reply to  Ron Long
August 30, 2021 2:06 pm

Speaking as a descendant of a range of mammals that were only allowed to multiply and diversify after the dinosaurs were knocked for 6 I say, bring on the asteroids! It is they that allow life to evolve here. But, please wait a few decades till I’m gone from this earth just the same…

Reply to  Ron Long
August 30, 2021 2:27 pm

Okay, but I’ll talk to the shrimps first, starting with my fossilized shrimp from the Mazon Creek district at Braidwood. Oh, and I’ll discuss it with horsetail plants, too, if I can find a bunch. Both were around during the Carboniferous epoch and are still here today. 🙂

Somehow, they survived everything and still live long and prosper these days (except when the shrimp get caught in nets and hauled in.

Ron Long
Reply to  Sara
August 30, 2021 6:00 pm

I don’t remember Bubba Gump mentioning fossilized shrimp…

Reply to  Ron Long
August 30, 2021 8:08 pm

I can send a photo of it, if you like. 🙂 The Mazon Creek district down near Braidwood, IL, has tons of fossils of all kinds, in iron ore concretions.

You’d be surprised what existed back in The Long Ago and still exists today. Sharks, for example; they don’t have a bony skeleton, but they do have teeth and some species will swim up a river to give birth. Fossil shark teeth going back 60 million years can be found in the Washington, DC/Maryland parks area.

Reply to  Sara
August 30, 2021 9:55 pm

I suspect crocodiles and cockroaches survived quite well and will do so again, dang it!

Reply to  Sara
August 30, 2021 9:53 pm

Ever been to Meteor Crater? There have been many which have hit Earth, some of them utterly devastating to life. Outside of us killing ourselves via nuclear war, I can’t imagine a greater, or more likely danger to the end of Mankind and the world as we know it other than by a meteor impact.
Maybe I need a more vivid imagination but, I do think, the dinosaurs would agree with me.

Reply to  .KcTaz
August 31, 2021 1:53 am

Maybe not the end of mankind but the end of western civilisation through the large scale adoption of woke “culture”. That is what we have to fear for future generations not the hoax of man made Climate Change.

Reply to  Hashbang
August 31, 2021 7:05 am

April 1st is not until 2022 now.

Richard Page
August 30, 2021 12:01 pm

So. That’s all fine and seems like a good idea, but then what happens to the deflected asteroid? The law of unintended consequences would kick in at that point with a rogue rock heading God knows where and subject to the gravity effects of the other bodies in the solar system – chances are it’d come straight back after a few years from an unexpected direction. My money would be on either complete destruction or slowing it right down so it could be nudged into a stable orbit or fall into the sun.
As to Orion – we’ve got enough nukes to try it but good luck trying to get clearance for any atmospheric testing, that won’t happen. Of course, if we can get to the moon and put a base there, that’d be where the development could be done – as long as we’re discussing sci-fi of course!

August 30, 2021 12:12 pm

DRil baby drill!

I thought Bruce Willis and some drilling guys fixed that some time ago…. great song from Mr Tyler, better than listening to the ignorant Chuckie truant.

Michael in Dublin
August 30, 2021 12:13 pm

This glamorous “Science Fiction” research project will squander billions on the pet project of a few. I find this obscene.

Reply to  Eric Worrall
August 30, 2021 7:15 pm

His plan is for the politicians he prefers to use that money and more to pay people to NOT DO ANYTHING PRODUCTIVE including VOTING FOR HIS PREFERED CANDIDATES.

Just another greedy leftist.

Michael in Dublin
Reply to  Drake
August 31, 2021 3:08 am

I am opposed to governments doling out taxpayer money to their pet projects. I am for smaller government with fair taxation and for people to decide where their money should go. I do not support any of the fifty shades of left politicians who keep coming to my door begging for my vote.

Michael in Dublin
Reply to  Drake
August 31, 2021 9:41 am

You are disingenuous in your slander. None of your accusations find any support in the 20 words I used. Your will not deceive any carefully reasoning person – only yourself.

Michael in Dublin
Reply to  Eric Worrall
August 31, 2021 3:18 am

I find alarm at possible asteroid strikes and coming up with ways to destroy/deflect them even more ridiculous than trying to engineer the 30 climate zones and subzones of the world. You sensibly reject the climate alarmism and yet are alarmist about asteroids. I am not going to lose any sleep over either.

Reply to  Michael in Dublin
August 31, 2021 10:05 am

You can’t differentiate between a real threat and an imagined threat? We would have far more success in deflecting an asteroid some day, than thinking we can change the climate to what ever we think we want. We don’t even understand natural variation yet, and can’t predict the weather/climate a year in advance.

Rick W Kargaard
Reply to  Eric Worrall
August 31, 2021 7:04 pm

It is entirely possible we can determine technology that will work without extreme cost.
If it can be deployed fast enough and a threat can be determined soon enough, major expenditure only needs to be made when a strike is determined to be imminent and inevitable.
Most of the current expenditure should probably be spent on detection and determining the level of intervention likely to be needed..

Richard Page
Reply to  Michael in Dublin
August 30, 2021 2:59 pm

You find the idea of preparing to save everybody on this planet from a known Extinction Level Event scenario obscene? Are you in favour of wiping out 80-90% of all life on this planet then? Or is it that the money would be better off being put into the pockets of Green activists or Climate Change racketeers and con artists?

Michael in Dublin
Reply to  Richard Page
August 31, 2021 3:28 am

If you have read even a small number of my posts on this site you would know I would be the last person to even give a dime or penny to the Greens but advocate for adapting to or even benefiting from changes in climate. However, I try and not worry about tomorrow and to live with a sober realism today. I try to present a well reasoned argument to those who get caught up with any sort of alarmism and show up the folly of building on sand to be dismayed when their houses are flooded or washed away.

Reply to  Michael in Dublin
August 30, 2021 3:46 pm

Perhaps if the current budgets of trillions had been well spent, you might have a point.

Reply to  Michael in Dublin
August 30, 2021 9:59 pm

Michael, the Earth has never experienced an extinction event from high CO2 levels. It has never boiled away and burnt up in a steam of heat or fire from CO2. Most all life has been destroyed by meteors. It seems to me that if there is any natural event that we should focus on it is a meteor hit.

Michael in Dublin
Reply to  .KcTaz
August 31, 2021 3:40 am

Hollywood loves making movies about out world boiling or burning or blowing up because people love watching them. These people should get a life and get out and enjoy the marvels around us in our world and not feed their anxiety with all sorts of highly unlikely extinction level events.

Richard Page
Reply to  Michael in Dublin
August 31, 2021 9:16 am

I do Michael, but I also feel it’s wise to be prepared for preventable disasters. Just as a precaution – otherwise why have seatbelts or airbags, emergency services or anything that limits or prevents damage or mortality?

Michael in Dublin
Reply to  Richard Page
August 31, 2021 9:51 am

There are everyday risks that at a minimal cost can be addressed to prevent serious injury or death like the use of seat belts and speed limits on certain roads. The likelihood of an asteroid falling on a populated area in the next millennium is tiny. Do we even have enough understanding of the physics to know what is likely to happen? I think not.

August 30, 2021 1:57 pm

“Obviously nobody wants a return to regular atmospheric nuclear tests. But surely after all the tests in the 1950s, we could stand to have a few atmospheric detonations in some remote part of the Pacific Ocean,”

Too many things wrong, here.

a few atmospheric detonations
More than a few. Orbital speed is over 18,000 mph. You have to get there one impulse at a time. Figure the G-force of the impulse shock you can subject the crew to. Now calculate the velocity gained. That gives you your first estimate at the number of BANGs you will need.

remote part of the Pacific Ocean
Now you are taking all the fun out of it. Consider: A few dozen nuclear BANGs in a long line as the ship gains speed and altitude, leaving a path of nuclear destruction, at least while the ship is at lower altitude.
So where to launch from?
I propose the launch site to be just to the West of, and immediately adjacent to Washington, DC. Directly after lift-off, the ship turns and heads East going for orbit. This path takes the ship directly over the city while it is still low and slow. A string of low altitude nuclear impulses (like a radiant pearl necklace) would have a most salutary effect on the swamp creatures there.

Richard Page
Reply to  Eric Worrall
August 30, 2021 3:02 pm

So why not build it in orbit in the first place? That way you don’t have to waste some nukes getting it the first few miles.

Richard Page
Reply to  Eric Worrall
August 31, 2021 2:38 am

I think it has also been proposed somewhere to use what’s already there. Wasn’t there an idea to use asteroids as Orions – explode nukes at one end and the bulk of the asteroid acts as radiation shielding for the crew at the other end?

Gordon A. Dressler
Reply to  Richard Page
August 31, 2021 8:32 am

Today, it costs somewhere between $2,000/kg and $10,000/kg to put mass into LEO (ref: ).

So, please, tell me again how much mass your Orion-type-spacecraft-to-be-built-in-orbit will have.

Oh, and I forgot to mention the costs of assembly of components in LEO, either by humans or robots.

Richard Page
Reply to  Gordon A. Dressler
August 31, 2021 9:18 am

How much would it cost to build it on the ground and never get clearance to launch?

Gordon A. Dressler
Reply to  Richard Page
August 31, 2021 2:59 pm

My back of the envelope calculation says “about a bazillion dollars”.

That’s roughly an order-of-magnitude less than building it in orbit and finding out that it doesn’t work.

Richard Page
Reply to  Gordon A. Dressler
September 1, 2021 3:50 am


August 30, 2021 2:02 pm
August 30, 2021 3:01 pm

There are five Lagrange points, moon is guarding us from anything coming from L2, so what is needed is three defence devises to cover the other 270 degrees of direction. There is a Trojan asteroid, the 300 metres diameter rock, and it intersects the Earth’s orbit but astronomers think it will never collide with the Earth.
2010TK7 as name suggest it was discovered less than a year ago.

Reply to  Vuk
August 30, 2021 8:20 pm

That name suggests it was discovered over a decade ago.

Reply to  jorgekafkazar
August 30, 2021 10:03 pm

I was wondering about that, jorge. 🙂

Reply to  jorgekafkazar
August 31, 2021 1:32 am

You are right, I wish 2010 was last year. An early symptom of Alzheimer’s, hope not. Cheers.

Richard Page
Reply to  Vuk
August 31, 2021 2:46 am

I think I’m right in saying that they’ve discovered several Earth Trojans, not just the one? Also that the Lagrange points are somewhat ‘dirty’ – by their nature they seem to attract quantities of debris (small rocks up to larger ones) on a regular (and temporary) basis – 2010TK7 is one of those rocks, orbiting around the Earth/Sun L4 point and seems to have stayed there longer than most.

Reply to  Richard Page
August 31, 2021 5:27 am

Richard, thanks for valiant attempt to dig me out of the hole

Curious George
August 30, 2021 4:47 pm

If the only tool you have is a hammer, every problem looks like a nail.
Why this obsession with guns? Why don’t we simply ram the rocket in the asteroid?

August 30, 2021 5:26 pm

The projected cost of startram gen 1, which would send cargo into orbit for less than $50 per kilogram, was at 19 billion dollars a small fraction of the cost of the ISS. So a 5000 tonne vessel could be placed there for a marginal cost of $250,000,000. No need to use hydrogen bombs.

Even then the capital outlay seems excessive. The concept of a huge rocket powered by fuel mined from a local methane plant could work out cheaper, or easier.

Reply to  Eric Worrall
August 30, 2021 5:50 pm

Robert Heinlein is rolling over. Railguns…..linear accelerators

Reply to  Bubba
August 30, 2021 8:29 pm

I would have thought that Elon Musk would have used his Boring machine to make a tunnel into a mountain and would be using a railgun to blast 2 ton frozen ice bullets into LEO, whereby it could be used for water shielding from radiation, or rocket ship fuel. Or blast solid aluminum/steel ingots into space where it could be refined into any shape you want.

Lot’s of G’s, so won’t work for humans, and maybe not sensitive satellites subject to massive G forces, but could be a cheap and efficient way to launch basic raw materials to space. They were experimenting with this 50 years ago, as were the Germans in WW2, to bombard London from France with explosive shells.

Project Harp in the 1960’s, a joint USA/Canada defense project, were blasting 16″ 400 pound projectiles at 3,600 m/s (8,050 mph) reaching an apogee of 110 miles, thereby performing a suborbital spaceflight. Why isn’t anyone doing this? Would even be more efficient off of the Moon, or Olympus Mons on Mars that is already 16 miles above the average Martian surface of the distance required to orbit.

August 30, 2021 9:45 pm

“An Orion powered Apollo mission would have included a tour of the inner solar system, with landings on the Moon and Mars, and a visit to Venus.”

Venus? I presume they don’t mean landing on Venus and what could Orion teach us that the unmanned explorers do not?

August 30, 2021 10:06 pm

I recall reading somewhere that the problem with blowing a meteor up is that, then, a thousand pieces hit Earth instead of one big piece. It seems to me a thousand small pieces are better than one huge rock but I have no idea.

Richard Page
Reply to  .KcTaz
August 31, 2021 2:56 am

The problem is that it’s difficult to tell what you’re going to get – if there are fractures in the asteroid, an explosion designed to knock it off course might just split it into 2 or 3 big fragments all on the same heading. An explosion designed to fragment the asteroid into small pieces that burn up would have to have multiple points around the asteroid, all detonating simultaneously. To my mind, the last option seems the best as well, but takes more time and effort to set up with more things that could go wrong. Besides, some people just like to shoot things with the biggest gun they can find!

Steve B
August 31, 2021 1:25 am

Why wait for 2182. Apophis, Friday 13th 2029 looks like a good candidate to test on.:)

August 31, 2021 3:41 am

If the modern precautionary principle was applied to this issue in the same way it has with climate change we’d all be taxed to death to pay for every whacky scheme going.

Considering how insane the west is becoming I sometimes think a sweet asteroid of doom is most welcome.

Michael S. Kelly
August 31, 2021 5:03 am

My career has been in space transportation, specifically commercial space transportation. My engineering specialty is propulsion, which in turn has motivated me to explore every source of energy possible. Project Orion got my attention when I first read Arthur C. Clarke’s description of it in the late 1960s. I couldn’t find any information on it (it was still classified) until 2002, when George Dyson (Freeman’s son) published Project Orion, a book I highly recommend. It contains a scenario wherein an asteroid is going to impact Earth, and we put together an Orion vehicle to go get it.

My take on it is this: It would be possible to take off from the surface of the Earth with an Orion without unacceptable fallout consequences. And an Orion could deliver a knockout blow to any incoming, no question about it. However, the U.S. and U.S.S.R. experience in nuclear testing in space showed that just a few nuclear bombs set off in space so polluted the existing radiation belts that our early suborbital human spaceflights would have been fatal to the astronauts had they occurred just a little earlier. The casualties today would be low Earth orbit satellites, and the International Space Station. I’m not sure this is something we would undertake, even if it meant letting the planet be destroyed.

Michael S. Kelly
Reply to  Michael S. Kelly
August 31, 2021 10:11 pm

Why the down vote?

August 31, 2021 7:46 am

In 1960 the US Army Corp of Engineers did a study Mining in Space. They recommended a spaceship that could take off from a runway go into space and return. That was rejected but the idea is good because of reliability and availability.

A manned ship with cargo capacity for tools and explosives would allow the crew to evaluate the rock to determine the best method of pushing it off to someone else to deal with in a billion years or so that it does not return to us.

A little less on carbon taxes and more on really saving the earth.

August 31, 2021 8:04 am

Every scientist wants an existential threat to humanity which only he can avert.

August 31, 2021 9:58 am

To shoot at a meteorite makes little sense since almost all NEAs are not monolithic “rogue rock». Given the results of last direct study, it has become clear that they are essentially natural space debris, fragments of which are held together by gravity and cohesion – “flying gravel- rubble-boulder piles” (i.e. crambly through and through, not just on the surface). On the other hand such internal structure will completely block momentum delivery to the asteroid as a whole when using an impact or explosive approach to the asteroid deflection (i.e. similarly to the perfectly inelastic collision).
Therefore, the optimum way (especially in the case of relatively short warning times) is to have a specific and sufficiently sized solar-concentrating structure, which is ready to transportation toward the asteroid and operate – see: as well as relevant section in the Wikipedia (“Asteroid impact avoidance – Use of focused solar energy”).

Rick W Kargaard
Reply to  Viktor
August 31, 2021 7:17 pm

Don’t shoot at the asteroid but rather, land on it and shoot from it. Use the the recoil from multiple small ejections of the asteroid’s or comet’s own material to force it into a new course. Small enough pieces with force that will not be a threat in themselves and not to threaten the asteroids integrity.
I know, more science fiction but the conversation is thought provoking.

Reply to  Rick W Kargaard
September 1, 2021 4:09 am

Unfortunately, the impulse will not be transmitted to the crambly target in this variant. As well as if the material will be locally escaped after the impact (or explosion).

August 31, 2021 3:46 pm

Although the risk of an Earth impactor which causes more than localised damage is extremely low”

It is actually 100%, what you mean is that the risk is extremely low in the near future, which is correct. But it is not zero, it is true that any threatening asteroid would probably have been located by now, but a comet can come in at any time and hit the Earth with a warning time probably less than a year.

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