Project Orion keeps surfacing in propulsion literature and making the occasional appearance on the broader Internet. A case in point is a vigorous defense of Orion-style engineering by Gary Michael Church on the Lifeboat Foundation blog. Church is rightly taken with the idea of propelling payloads massing thousands of tons around the Solar System, but he’s also more than mindful of the realities, both political and economic, that have kept Orion-class missions in the realm of the theoretical. It was, after all, the nuclear test ban treaties of the Cold War era that brought the original project to a close, and anti-nuclear sentiment remains strong in the public today.
But the Orion idea won’t go away because it is so tantalizing. Church runs through the relevant information, much of it familiar to old Centauri Dreams hands. Freeman Dyson and Ted Taylor were working on a concept in which a large percentage of the energy of a nuclear explosion — these are small nukes of the kind Taylor specialized in — could be concentrated in one direction. If you can do that, you can blow that energy into a propellant slab to create thrust, assuming that a massive pusher plate would be present to absorb the blast without melting in the process.
Image: An Orion-class mission under power. Credit: Adrian Mann.
Remarkably, the research indicated that this was possible because the blast would last for such a tiny amount of time as the craft, boosted by each subsequent bomb, accelerated through space. It’s hard to describe what riding aboard such a craft would be like, though Church likens it to repeated aircraft carrier catapault launches. My own guess is that even the most highly advanced pusher plate/shock absorber combination would have trouble making this ride anything but a nightmarish if potentially survivable experience. But Dyson and Taylor had numbers showing that it was worth pursuing, and there were grand thoughts about shaking out an Orion-class mission back in the late ‘60s by going all the way to Saturn’s moon Enceladus.
Defending Orion Through Radiation
A defense of Orion will need to produce reasons for its resurrection, and Church offers several, beginning with the radiation that bathes deep space. Some kinds of cosmic rays pose a serious threat. From the essay:
The presence of a small percentage of highly damaging and deeply penetrating particles?—?the heavy nuclei component of galactic cosmic rays makes a super powerful propulsion system mandatory. The tremendous power of atomic bomb propulsion is certainly able to propel the heavily shielded capsules required to protect space travelers. The great mass of shielding makes chemical engines, inefficient nuclear thermal rockets, the low thrust forms of electrical propulsion, and solar sails essentially worthless for human deep space flight. Which is why atomic bomb propulsion is left as the only “off the shelf” viable means of propulsion. For the foreseeable future, high thrust and high ISP to propel heavy shielding to the required velocities is only possible using bombs.
It’s true that the bulk of the radiation we’ve so far had experience with in long-duration spacecraft has been more manageable, largely because a venue like the International Space Station is shielded by the Earth’s magnetic field. But as we start talking about multi-year missions, our thinking has to turn toward practical methods of shielding far beyond Earth’s orbit. Church sees the need for shields massing hundreds of tons that could hardly be propelled by conventional methods, whereas an Orion-style craft, bulking itself up with lunar ice deposits from the Moon’s north pole, could boost out of lunar orbit with a full and robust radiation shield. In his view, then, only Orion can take us on manned missions to other planets, much less the kind of interstellar missions sometimes contemplated for this technology.
But shielding a spacecraft, at least within the Solar System, may not be as demanding as this, as at least one space scientist believes. Robert Zubrin has been working out the basics of Mars Direct for some time now, and the radiation issue is a major concern for him as well. Where Church says “An appreciation of the heavy nuclei component of galactic cosmic radiation, as well as solar events, will put multi-year human missions beyond earth orbit on hold indefinitely until a practical shield is available,” Zubrin (in the latest edition of The Case for Mars) refers to this kind of talk as ‘scaremongering’:
Cosmic rays deliver about half the radiation dose experienced throughout life by people on the surface of the Earth, with those living or working at high altitude receiving doses that are quite significant. For example, a trans-Atlantic airline pilot making one trip per day five days a week would receive about a rem per year in cosmic-ray doses. Over a twenty-five-year flying career, he or she would get more than half the total cosmic-ray dose experienced by a crew member of a two-and-one-half-year Mars mission.
As the issue continues to be debated, we also have to look toward future interstellar missions, no matter what kind of propulsion system we commit to the task. If we’re talking human missions, it will clearly be essential to learn more about the shielding effects of the heliosphere on galactic cosmic rays to find out what kind of shielding will be needed for a crew that moves into interstellar space. Dana Andrews (Andrews Space), who has collaborated in the past with Zubrin on magsails, is just one researcher who has examined the issue. See his “Things to Do While Coasting Through Interstellar Space,” AIAA-2004-3706, 40th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit, Fort Lauderdale, Florida, July 11-14, 2004. You may find my article on Andrews’ work Dust Up Between the Stars helpful as well.
The Imperative of Species Survival
The real motivator for Orion technology may not be crew protection — much of our future work in the outer system and beyond may well be robotic — but the need to protect the planet from asteroids or comets on dangerous trajectories. This is Church’s ultimate justification, the one he hopes will trump the anti-nuclear lobby and bring clarity to the issue, and he points out that an Orion-class mission would be just the ticket if we had to send a human crew to an errant object deep in the Solar System to begin adjustments to its course. Thus this:
It is within our power to defend Earth from the very real threat of an impact, and at this time self-defense is the only valid reason to go into space instead of spending the resources on Earth improving the human condition. Protecting our species from extinction is the penultimate moral high ground above all other calls on public funds.
And this final thrust:
A powerful force of nuclear powered, propelled, and armed spaceships cannot guarantee Earth will not suffer a catastrophe. The best insurance for our species is to establish, in concert with a spaceship fleet, several independent self-supporting off world colonies in the outer solar system. The first such colony would mark the beginning of a new age.
Church’s essay is well thought out and deserves more attention than it seems to have been getting, considering that Orion gets us around problems like the harnessing of massive energies within an internal engine without melting the engine, something that uncontained nuclear-generated plasma and pusher plates could resolve. Of course, George Dyson explains all this in his wonderful account of his father’s and Taylor’s work Project Orion: The True Story of the Atomic Spaceship (2002), but I’m always thinking in terms of keeping deep space concepts in front of the public, and Church lays out the basics in ways that might attract a Net-reading generation familiar mostly with chemical rockets.
Image: An Orion vehicle departs for Mars. Credit: Adrian Mann.
The question then becomes, if we were to explore this technology again, would the drivers Church mentions be enough to get us past the anti-nuclear lobby to begin testing the concept meaningfully? Because right now we have only the sketchiest knowledge of how adaptable Orion might prove to be, and only the reassurances of its proponents that a human crew would survive the ride. Developing an Orion prototype would demand testing it off the planet, and that presupposes lofting a great deal of nuclear material into space. We all remember the fuss kicked up by the plutonium carried aboard the Cassini probe to Saturn. Can the planetary insurance imperative become a credible enough issue to turn the prevailing view of nukes around?
You know, Project Orion must be a popular name!
The Constellation Program , still has an Orion project, slowly dying on the vine, alas!
A SETI-related NASA effort Project Orion , somewhat like the VLA, never went anywhere.
There may have been other Project Orions?
It’s taken a long time but the Ted Taylor/Stan Ulam – General Atomics project is no longer is as obscure as it used to be.
It’s amazing but this is the only, you-could-build-today fusion propulsion system known.
George Dyson’s book probably documents it (don’t have mine on hand) but von Braun and Marshall (after a fashion) inherited the project in the 1960’s. Von Braun was very interested in it and a study made, one can download the unclassified document by looking at the Wiki entry:
http://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion)
One reason the technical aspects of the project remained classified for so long was the size of the thermonuclear ‘pulse units’. That was the 1960s, we don’t know, probably can’t know, just what the DOE has come up with in the last nearly 50 years! Those dudes may be really small by now.
For some nice technical data, and drawings not even in Dyson’s book consult
Scott Lowther’s site Upship, the classic is here:
http://www.up-ship.com/eAPR/ev1n4.htm
Not to be forgotten are the contained nuclear-pulse propulsion systems, by that forgotten genius Dandridge Cole…. had some cool off shot designs from inspired by Orion.
See Lowther’s site.
Orion type propulsion makes more sense today than back then because we know much more about how to harness more of the output of the nuke. Of course, all info on how to make a tiny nuke is classified as is info on how to direct the pulse. However, one might consider anti-matter induced FISSION (no, not fusion) as a way to get more efficiency out of a nuke or to use less than a normal critical mass of fissionable material. This would also give more control over when (or if) the pulse goes off.
Another possibility is to use materials with very low critical mass such as certain isotopes of Curium. Such isotopes are normally produced in such small amounts as to not be useful for weapons but for a deep spaceship, it might make sense simply for the total mass savings.
Then there is the old “nuclear salt water rocket” idea (was it Zubrin’s idea?) where fissionable material dissolved in water formed a critical mass just aft of the rocket producing what amounted to a continuous nuke explosion.
Of course, one has to mention the Mag-Orion and Mini-mag Orion concepts:
http://en.wikipedia.org/wiki/Mini-Mag_Orion
OK, I have to apologize to Paul Gilster who seems to have already covered all of this:
https://centauri-dreams.org/?p=1430
Until about 6 months ago I had no idea Centauri Dreams existed and I thought I was dreaming alone of this stuff.
Good Job Paul.
Responding to the points Paul Gilster made in the last paragraph, quoted next:
“The question then becomes, if we were to explore this technology again, would the drivers Church mentions be enough to get us past the anti-nuclear lobby to begin testing the concept meaningfully? Because right now we have only the sketchiest knowledge of how adaptable Orion might prove to be, and only the reassurances of its proponents that a human crew would survive the ride. Developing an Orion prototype would demand testing it off the planet, and that presupposes lofting a great deal of nuclear material into space. We all remember the fuss kicked up by the plutonium carried aboard the Cassini probe to Saturn. Can the planetary insurance imperative become a credible enough issue to turn the prevailing view of nukes around?”
LJK replies:
Society’s attitude towards nuclear power in space and elsewhere has definitely changed since the launch of Cassini in 1997, no doubt largely in part because people have bigger things to worry about than whether a nuclear-powered space probe might come crashing down on our heads, regardless of the fact that RTGs are designed to survive atmospheric entry and even the explosion of the rocket (the SNAP 27 RTG carried aboard the Apollo 13 Lunar Module Aquarius survived re-entry and being dropped into the Pacific Ocean in April of 1970, which was certainly not its original destination).
The Mars Science Laboratory (MSL) robotic rover now called Curiousity, scheduled for launch from Cape Canaveral on November 25, is using the latest version of RTG for its power, similar to the twin Viking landers in the 1970s. If there have been anti-nuke protests over Curiousity, they certainly have not been at the same level or media attention that Cassini got fourteen years earlier.
I would like to think this lack of negative response is due to the public becoming more educated about nuclear power and how it is handled aboard spacecraft (Cassini has been “safely” kept 800 million miles from Earth since it went in orbit about Saturn in 2004), but I know better.
Are readers aware that before the tragic earthquake in Japan last March which affected several of their nuclear power plants (using older and flawed designs, I might add), certain leaders in the environmentalist movement were starting to tout nuclear energy as a cleaner and even safe alternative to fossil fuels – especially after the huge oil rig explosion and spill in the Gulf of Mexico in 2010, which was not the worst oil spill there, FYI. See this CD post and comments on the Japanese nuclear reactors here: https://centauri-dreams.org/?p=17129
Unless there is some big breakthrough in fusion or antimatter propulsion relatively soon, Orion is our best bet for getting a spacecraft to the stars any time soon. In addition to the fact that we already have the “fuel” for this project, technically Orion does not require a big and sophisticated space infrastructure to build it compared to other plans. For example, scooping stuff out of the atmosphere of Jupiter is really cool, but I would be surprised if my great grandchildren will ever see that happen in their reality. The original Daedalus team was so optimistic back in its day.
As I have said elsewhere before in this blog, there is at least one nation with a sophisticated and growing spacefaring infrastructure and nuclear program, along with a lot of remote, sparsely inhabited territory, that could potentially make Orion a reality. Will the US and other nations follow suit, or will we get bogged down with debating the minute details back and forth and whining about funding and priorities which have kept us from colonizing the Moon and Mars for the last four decades.
Speaking of humans, do we really need them aboard Orion or any other starship plan? I know it is romantic to think of having real people aboard a ship sailing through the galaxy, but is it realistic or necessary for a real interstellar vessel, not the kind we’ve been force-fed by Star Trek and a lot of other science fiction tales?
Unless a miracle happens tomorrow, no one living today will be flying off to Alpha Centauri in person. By the time our first star probes are on their way, humanity will be different from us in many important ways, despite how most science fiction depicts future human society with fantastic technologies but people remaining the same as they are now.
I can see future humans experiencing interstellar exploration vicariously through virtual reality, with billions tapped into the streams of data and images being returned by the probes they sent to the stars. It will actually be better and much fairer (and safer) than having a relative handful of astronauts get to experience strange alien worlds directly or just sitting there watching them via the media. Plus this avoids worrying about whether a human crew could handle the propulsion shock from Orion or any of the other potential dangers from other types of starship propulsion methods.
Yes, I think we really need to start getting off this idea of having to have actual human beings aboard our starships (unless we are doing some kind of Save Humanity Worldship effort), as I think it is holding us back from getting those crucial first missions to the stars as much as all the other issues we need to overcome to make interstellar travel a reality.
A small pellet of say plutonium could be compressed by a multi beam laser to critical density or even if to subcritical density it would produce a huge amount of energy to propel us around the solar system—–the radioactive residue should be quite small as it would be ejected at very high velocity escaping the solar system, however some of the residue would embed itself or even make the focusing nozzle radioactive due to neutron interactions….IMO this design is more feasable than a fusion based project –
Given the attitude toward nuclear energy lately, I seriously doubt Project Orion would see a rebirth, especially with the ban on the usage of nuclear explosives in space.
And it’s a shame too. This seems to me to be the ticket for really getting out there, amongst the solar system.
Perhaps a chemical explosive powered prototype might be fashioned instead? I know it’s not the same, but still a step in the right direction, yes?
As usual, Paul, an insightful and instructive digest. Thank you.
You reference a few political objections towards the end, but the sad truth is that the Orion concept is actually political to the core. I honestly think that it Orion could only ever happen if the geopolitical landscape of our planet changed radically.
A single country sponsoring a space craft that used nuclear bombs for propulsion? What would the other several hundred countries on Earth say about that? Whatever reassurances the ‘Orion’ country gave, I can guarantee that hundreds of other countries would object profoundly. We are talking about a spaceship that is essentially a highly mobile, supercharged bomb. Doesn’t matter what the truth is, doesn’t matter if the country doing this is promising to conduct the tests on the far side of Saturn… No one else is going to say yes. And if they did, then (assuming it’s a democracy) they wouldn’t be re-elected.
This has nothing to do with science or rationality (sadly). It has *everything* to do with politics and public fear.
And that’s before we’ve even started on terrorism or the possibility of “er, a few of our bombs appear to have gone missing”…
With great regret, it’s just not going to happen. Even with a single, unified world government, there would still be concerns about terrorism. So, even if you posit some far-future World-Gov, and a chemical technology that has million of people beetling around Saturn, even *then*, no one is going to approve this.
The consequences could just possibly be dire. The *fear* of those potential consequences mean the whole idea is simply a non-starter.
I’m not saying I approve of this state of affairs. I’m just saying it’s real.
Ain’t gonna happen. Which is a shame.
Thanks for the great blog.
Richard
There are still many other reasons that make Orion system attractive.
1) Multi-use, Multi-mission capabilities, once the vehicle is made it can be used for years, eventually the pusher plate may need to be replaced, but that plate can be dropped into the sun when it’s lifetime is over. This will reduce costs dramatically, allowing us to actually colonize the “outer system”
2) Minimize launch of nuclear materials. Thorium is found on the moon, it can be transformed in a breeder reactor into U233 which can be used in nuclear bombs. All that is needed is seeding materials to begin the process. So radioactive material issues for Earth are minimized significantly.
3) Once we have a platform that allows us to travel within the solar system at a low cost and allows us to transport large amounts of materials, we can then look at true space based solar power systems orbiting the sun providing power continuously. It would also allow asteroid mining.
4) Things we haven’t thought of. When you get a new tool there is always things we never thought of to use it for.
Orion was is and will be the only realistic and technologically feasible method of sending humans into deep space, at least for a very, very long time.
The radiation hazard is severe, although it can be mitigated not just with massive physical shielding, but with magnetic shielding as well (which can be used as a propulsion method as well).
The repetition rate for Orion, as least from what I remember reading, was high enough that it would feel like a continuous acceleration to the crew, except for the occasional misfire.
Hollywood, oddly enough, got the planetary protection aspect of “Orion” right in “Deep Impact”. Personally I think the ground launch potential of “Orion” needs re-examination in light of the fact that the concept of “no safe minimum” of radiation exposure has been discredited. But there are “Orion” like designs which have a huge potential for interplanetary applications. Dana Andrews, again, with Andrews Aerospace has worked on the Mini-Mag Orion concept which avoids the “bomb issue” by external compression of fission/fusion charges to criticality by using a z-pinch. This concept can achieve high thrust and high Isp without the need for a massive pusher plate and hoping one’s shock absorbers work or else you’re strawberry jam.
No.
In the aftermath of Fukushima (which will be with us for a long time) there is no chance. A program like that would imply that NASA had decided that nuclear propulsion was the way to go, and that would require a major policy statement, which would be political suicide for anyone in Congress who championed it.
There could also be fierce international opposition, especially if, at the same time, we’re still pushing hard to keep other nations, like Iran, from developing their own nuclear capabilities (whether or not they are for weapons).
The only thing that changes this equation is an imminent (but not too imminent) threat of an asteroid strike — e.g. there was a high risk a asteroid large enough to cause regional devastation crashing down on Earth a decade or two from now.
Even then, nuclear would, at best, be one of several options the research money would be pumped into, and if there was another viable solution, then Orion would likely be shelved again.
I really don’t think that the lure of self-sustaining colonies as a hedge against a catastrophic disaster impacting Earth is going to help. We’ll be lucky if there is anyone alive today who will see the first manned mission to Mars become a reality, and even after that finally happens, we’re still hundreds of years away from any chance that the human race can survive long term without Earth still being around.
Long before any of that happens, we will have an extremely effective asteroid early warning system in place, and the means to divert anything that is coming our way with plenty of time to spare.
I wish it was otherwise. I would be the first to cheer a strong and sustained push into space, but economically and politically it just doesn’t make any sense, and absent some game-changing event (like contact with ETI, new technology making space flight far cheaper, or an imminent unforeseen calamity) I don’t see that changing any time in the next few decades.
I have been one of those too who wants to bring back Orion..especially if…
Those speeds are correct for the low momentum option…3-10 percent of light? Is that right?
Darpa is part of an agency that has the fuel…and its right now !!!
I really think you guys are overly concerned about anti-nuke sentiment. If the major nuke powere want to do it it could be done and there was no bigger antinuke environmentalist than Carl Sagan and he was for it. I am an environmentalist and I am for it
Best yet it could be done now and it would have a real stimulative effect now !
People need jobs lets build something
I’m a bit mystified as to just how Orion is supposed to protect us from dangerous impacts. Civilization-threatening impacts happen at a rate of one per million years or so; are already easily detectable decades in advance using current technology; and could almost certainly be deflected using a wide range of techniques, several of which are probably already within our grasp technologically and none of which require building or detonating hundreds of nuclear weapons.
If the threat of impact is Church’s “ultimate justification”, then it’s a pretty feeble justification.
Doug M.
While public attitudes to all things nuclear might have swung negative in the aftermath of Fukushima, in time memories will fade and attitudes will change. Who knows what the public opinion landscape may be like in twenty, thirty or fifty years when the infrastructure for this kind of project may actually exist? The future is (hopefully) a long time, and public opinion, political will and capability only have to come into alignment once for Orion, or something very much like it, to happen.
“The person is smart but people are dumb panicky animals”
Ljk put me on to that film quote and I think it useful to start any discussion of the public perceptions of the dangers of radioactive material with it. It seems to me that moment of Orion’s resurrection will coincide with the public perception of the dangers of radioactivity coming becoming more realistic. To help facilitate this process I propose we should avail them of the following facts.
1) It is quite unclear if there is a threshold limit below which ionizing radiation poses no increased risk of cancer, and many even decrease it. Such an inverse in vivo correlation of oncogenesis and radiation exposure at low levels is more or less proved for uv exposure, and it is interesting that those that work in the nuclear industry seem to have lower rates of cancer than a similar cohort in the general population.
2) Coal fired power generation releases much more radiation into the environment than the equivalent nuclear plant.
Just for fun:
BEFORE ORION THERE WAS THE NUCLEAR POTATO CANNON:
“Every kid who has put a firecracker under a tin can understands the principle of using high explosives to loft an object into space. What was novel to scientists at Los Alamos was the idea of using an atomic bomb as propellant. That strategy was the serendipitous result of an experiment that had gone somewhat awry.
“Project Thunderwell was the inspiration of astrophysicist Bob Brownlee, who in the summer of 1957 was faced with the problem of containing underground an explosion, expected to be equivalent to a few hundred tons of dynamite. Brownlee put the bomb at the bottom of a 500-foot vertical tunnel in the Nevada desert, sealing the opening with a four-inch thick steel plate weighing several hundred pounds. He knew the lid would be blown off; he didn’t know exactly how fast. High-speed cameras caught the giant manhole cover as it began its unscheduled flight into history. Based upon his calculations and the evidence from the cameras, Brownlee estimated that the steel plate was traveling at a velocity six times that needed to escape Earth’s gravity when it soared into the flawless blue Nevada sky. ‘We never found it. It was gone,’ Brownlee says, a touch of awe in his voice almost 35 years later.
“The following October the Soviet Union launched Sputnik, billed as the first man-made object in Earth orbit. Brownlee has never publicly challenged the Soviet’s claim. But he has his doubts.”
A report can be found here:
http://nuclearweaponarchive.org/Usa/Tests/Plumbob.html#PascalB
see also
The section:
The first nuclear-propelled manmade object in space?
At Wiki
http://en.wikipedia.org/wiki/Operation_Plumbbob
One more entry:
Cole/Helios nuclear pulse vehicles.
See the following for Dandridge Cole ‘contained’ nuclear pulse vehicles, and some really cool illustrations.
http://up-ship.com/blog/?p=5353
I think our fear of all things nuclear is a little unfounded.
Take what is widely regarded to be the worst nuclear disaster in history, Chernobyl. The World Health Organization reported in 2005 (see: http://www.who.int/mediacentre/news/releases/2005/pr38/en/index.html ) that at that time there were only 50 deaths directly attributable to radiation exposure from the accident (mostly workers on the site following the explosion).
Also, the net environmental impact seems to have been a positive one. A quote from a Chernobyl Wikipedia article (see: http://en.wikipedia.org/wiki/Chernobyl_after_the_disaster#Wildlife_status ): “The Exclusion Zone around the Chernobyl nuclear power station is reportedly a haven for wildlife. As humans were evacuated from the area 25 years ago, existing animal populations multiplied and rare species not seen for centuries have returned or have been reintroduced, for example lynx, wild boar, wolf, Eurasian brown bear, European bison, Przewalski’s horse, and eagle owl.[13][14] Birds even nest inside the cracked concrete sarcophagus shielding in the shattered remains of Reactor 4.”
As for the Challenge of protecting a crew in space for significant periods of time, and coming up with a sane means of high performance transportation for large masses, we already have the technology to accomplish this.
We already have large laser facilities capable of initiating fusion in a deuterium pellet. Line your pusher plate with black silicon under a layer of transparent Titania ceramic and you absorb EMR 99.9% of the radiation produced from your blast and turn it into power for the vessel. The Titania is tough enough to protect the black silicon from abuse.
At the same time, your vessel is large, cylindrical, maintains a strong external magnetic field and the outside of the ship has a thick wall composed of water ice and various minerals. The outer wall, 3-4 meters thick will stop just about anything the solar system or supernovae can dish out. The Cylinder rotates creating artificial gravity. The ship is large enough to carry a crew of 10-20 people, with enough hydroponic agriculture to keep them happy and well fed on a trip to Jupiter or Saturn. Figure synthesized meat for beef, poultry, and fish and enough spices and herbs to provide both cooking and medical needs, and you could create a quality of life that would be more than passable, even for extended periods.
Add the shear joy of weightless play spaces, and deep space based research, and I can imagine people all over the place jumping at the chance to participate. I’d also personally suggest stable, healthy, happy mated pairs or possibly small polyamorous families. Close familial emotional bonds will be vital for maintaining mental and emotional health. Such a crew should have at least one doctor with surgical experience plus a nurse practitioner also with surgical experience. Robotic medical resources would be a second option if AI is sufficiently advanced, because the communication delay between earth and the vessel would render anything but the most basic remote medical procedures pointless.
We have most of the technology well in hand. We are far better suited at this point in time to accomplish a project of this order, than America was in putting a man on the moon in 1960. What we lack, is vision, will and the mental clarity to appreciate how important it is that humanity leave the planet in large numbers. The good or the bad news is that earth can no longer support a population over 7 billion without serious failure to basic environmental systems. The time to precipitate a meaningful future is now.
@A. A. Jackson
Allow me to point out that DoD had small (8″), tunable, multi-kiloton (10-20) warheads in the late 50s.
wiki Davy Crockett (nuclear device).
A. A. Jackson mentions the infamous Project Thunderwell, where during an underground nuclear bomb test a thick metal hatch was supposedly blow into space by the explosion, technically beating the Soviets with their claim of having the first artificial object in space with Sputnik 1 in October of 1957.
Side Note: This is often forgotten now, but in the really early days of the Space Age, the 1949 launch of a V-2 rocket with a smaller WAC Corporal atop it reached 250 miles before plunging back to Earth. That flight certainly made it into space, even if only briefly. Other rockets in the pre-Sputnik era also reached over 100 miles in altitude, higher than the currently defined “start” of space above our planet’s surface of 62 miles (100 kilometers).
However, if you continue reasding the text of the first link AAJ provided in his post, you will see that the hatch probably did not make it into space. Besides, even if it did, it would be only a useless hunk of metal unable to return any data about space or that it made it up there. Those darn Soviets still get the credit for having the first working satellite in Earth orbit, even though von Braun’s Huntsville team might have beaten them at least one year earlier had they been allowed to proceed with their satellite plan. Then again, without the Soviets goading the US with their early space successes, would we have gotten as far as we did without being provoked?
Read on:
“But the assumption that it might have escaped from Earth is implausible (Dr. Brownlee’s discretion in making a priority claim is well advised). Leaving aside whether such an extremely hypersonic unaerodynamic object could even survive passage through the lower atmosphere, it appears impossible for it to retain much of its initial velocity while passing through the atmosphere. A ground launched hypersonic projectile has the same problem with maintaining its velocity that an incoming meteor has. According to the American Meteor Society Fireball and Meteor FAQ meteors weighing less than 8 tonnes retain none of their cosmic velocity when passing through the atmosphere, they simply end up as a falling rock. Only objects weighing many times this mass retain a significant fraction of their velocity.
“The fact that the projectile was not found of course is no proof of a successful space launch. The cylinder and cover plate of Pascal-A was also not found, even though no hypersonic projectile was involved. Even speeds typical of ordinary artillery shells can send an object many kilometers, beyond the area of any reasonable search effort.”
@ljk
Not that Sputnik returned much useful information (beep beep beep beep).
Further, Eisenhower forbade the experimenters from sending their sounding rockets into LEO. Didn’t want to excite the Reds too much, don’t you know? In hindsight, an appalling lack of vision, rather like Nixon and the future of American preeminence in Earth orbit, a.k.a., da Shuttle).
Our future in space demands a cheap and safe way to get into orbit.. We should put all our efforts into the space-elevator concept. That would really be a game changer. Once the first on is up and running, many more would very soon be built.
Hi everyone, I’m only a humble chemistry undergraduate, however I’ve been an avid follower of centauri dreams for some years now, just a shout out to those who maintain and use the site you’ve done a wonderful job, keep at it!!
My question, concerning the radiation hazard’s would it be feasible to generate onboard shielding on the Orion or indeed any interplanetary ship? I.e. Earth’s magnetic field?
Sputnik 1 actually did more than just go beep:
http://www.mentallandscape.com/S_Sputnik.htm
And it definitely did more than that metal lid. :^)
Ironically, the satellite that became Sputnik 3 was originally going to be the first satellite launched by the USSR, but the powers that be decided to go for something simpler, thus the sphere with four whip antennae. Had what became Sputnik 3 gone up first, that would have had an even bigger impact on the West. Of course Sputnik 2 with Laika the next month was impressive, too.
Hi Mike,
I think that it’s possible for a ship to generate a strong enough field for it to deflect most nuclei it would encounter at high speeds, but a good thick hull will certainly be necessary. I think a real game changing technology would be a thin material that could shield against energetic particles to keep its human cargo safe.
I was just thinking of a design this afternoon. It basically consists of a ship that is attacked via internal spars to a bigger outer hull with about six or more feet between layers. Assembled in space, the space between the hulls would be filled with water to protect against deleterious particle/ship interactions. Would this he effective or feasible?
@Denver
“Further, Eisenhower forbade the experimenters from sending their sounding rockets into LEO. Didn’t want to excite the Reds too much, don’t you know? In hindsight, an appalling lack of vision, rather like Nixon and the future of American preeminence in Earth orbit, a.k.a., da Shuttle).”
I’m not sure about this being “an appalling lack of vision things”. The decision has to be balanced against the back drop of the cold war and the real threat of WWIII. One could equally say it was an inspired decision – one it helped to prevent the outbreak of war and two, let the USSR carry on expending huge sums on essentially useless (to them, at the time) projects and three, initiate a race (the space race) that will expend even more exorbitant sums – helping eventually to cripple the USSR financially.
As to the “beep, beep, beep” comment, I think intellectually it was a bit more chilling than anything else they could have done. Like all good horror movies, what is left to the imagination is far more scary than any actual image.
ljk>
I am sure that ‘man hole cover’ did not make it to orbit.
Among the nearly 60 V2, Bumper, Hermes launches at White Sands from 46 to 52, I remember one where grenades were fired at apogee , someone calculated there was a probability that fragments went into orbit. (I think Willy Ley documents this.) No way to know, I don’t even think they had radar tracking that good in those days. This would have been before 1950, I think.
Seems Ley , I can no longer find the reference, related that the Peenemünders at White Sands presented a brief blueprint to the Army of using something like Bumper to put a grapefruit tin foil ball in orbit, but nothing came of it. (I do believe that von Braun and crew presented a more detailed artificial satellite study just a little after the 1946 Rand study.)
There is also the Jupiter C ‘accident’ designed by von Braun and the Redstone guys. During the testing of ICBM re-entry materials von Braun was going to have the upper stage ‘mis-fire’ putting it into orbit in 1956. I don’t think the Army would have cared, but the Eisenhower administration was apparently on the look out for such a stunt, found out, and ordered von Braun not to do it. (Eisenhower wanted a ‘civilian’ launch only, even tho the NRL was involved with Vanguard.
I understand that the ‘accident’ Jupiter C was stored and used later for the Explorer launch.
There isn’t a snowflakes chance in hell that Orion like spacecraft will be built. While it is decent of Church to suggest that the radiation concerns to earth are ameliorated by restricting the flights to extra-planetary ones, he completely misses the ramifications if this were to become the means for opening up planetary and deep solar flights. Orion would stimulate the nuclear bomb industry resulting in new warheads… err fuel elements, which would lead to proliferation, losses during production and the inevitable launch failures. I do not think this is any way acceptable.
Furthermore, I am unclear why this approach is so popular. Earlier posts on the Icarus fusion drive suggested that its use for solar system propulsion has a similar performance. So why go with a-bombs when a cleaner, non-proliferative approach is on the horizon? Perhaps that horizon is too far away for some, but I would rather we bring that one closer with R&D than assume that we must do Orion as the nearest term “viable” option.
A. A. Jackson said on November 17, 2011 at 8:08:
“Among the nearly 60 V2, Bumper, Hermes launches at White Sands from 1946 to 1952, I remember one where grenades were fired at apogee, someone calculated there was a probability that fragments went into orbit. (I think Willy Ley documents this.) No way to know, I don’t even think they had radar tracking that good in those days. This would have been before 1950, I think.”
The October, 1950 issue of National Geographic Magazine had an article on the V-2 launches at White Sands complete with full-color photographs. Some kind soul put them online here:
http://rocketdungeon.blogspot.com/2011/01/big-v-2-history-post.html
The blog author notes the following:
“The photos below are of round No. 56, launched November 18, 1949. Along with the pictured camera, it carried a Pirani temperature probe, air sampling bottles (U. Mich.) and a ‘grenade experiment’ (Army Signal Corps.). It reached an altitude of 77 miles. (via ROTW, Peter Alway, pp. 21-22.)”
So perhaps this is your grenade experiment launch in question. Or was there more than one test?
Not to be a party pooper again, but I have to wonder if any fragments could ever have reached orbit? I am sure they went much higher than the carrier rocket did, though. And what was the point of exploding grenades at high altitutde anyway? I wonder how they did it without affecting the other instruments onboard?
Alex Tolley said on November 17, 2011 at 10:28:
“There isn’t a snowflakes chance in hell that Orion like spacecraft will be built. While it is decent of Church to suggest that the radiation concerns to earth are ameliorated by restricting the flights to extra-planetary ones, he completely misses the ramifications if this were to become the means for opening up planetary and deep solar flights. Orion would stimulate the nuclear bomb industry resulting in new warheads… err fuel elements, which would lead to proliferation, losses during production and the inevitable launch failures. I do not think this is any way acceptable.”
LJK replies:
Since the early days of the Cold War when nuclear warheads started being placed atop missiles and rockets along with those carried by bomber planes, the warheads are designed to survive re-entry through Earth’s atmosphere as they arced up into space (usually over the Arctic) and then down towards their targets.
Similar technology is used to keep the RTGs on deep space probes like Cassini from coming apart in case the rocket explodes or plunges back to Earth. Elsewhere on this blog recently, I provided a real-life example with the SNAP 27 RTG aboard the Apollo 13 Lunar Module Aquarius, which came down in the Pacific Ocean in April of 1970 and has never shown any signs of radiation leakage since.
So, ironically, these nuclear bombs would not prematurely explode until they were meant to (a.k.a. World War 3). Nuclear bombs are also designed not to detonate until certain preplanned technical actions happen. Several bombers with nukes crashed in the 1960s, and although there was a potential danger from radiation leakage, none of them prematurely detonated.
All of these are time-tested safety features that would naturally be part of any Orion launch, whether from Earth’s surface or being transported into space. It might be more practical in the long run to assemble them in space for Orion, but obviously that would be no small undertaking – though it would be possible and it would still be easier and cheaper than mining materials from the atmosphere of Jupiter.
I am not foolish enough to assume that nothing might ever go wrong or that some individual or group might not try to take control of an Orion nuke for their own purposes, but I will assume that in this post-9/11 world that numerous safety precautions would be in place, especially in and/or involving space missions.
For anyone who actually remembers the Cold War, I think it is nothing short of a miracle that in all the decades since the first nuclear bombs were made in 1945, only two have ever been used in warfare. At their peak in 1990, an estimated 55,000 warheads alone were in possession between the US and USSR – and this does not even include all those other nations with their own nuclear bombs.
As Carl Sagan said in his 1980 PBS television series Cosmos, Orion is one of the best uses he could think of for nuclear weapons, and this from a man who went to his share of anti-nuke protests. Sagan also promoted the idea of “nuclear winter”, which said that in a major nuclear exchange, the climate would be so badly disrupted by all the Sun-blocking debris and smoke from fires that virtually every spot on the globe would be affected, not just the immediate targets of a nuclear attack.
That infamous scene from the 1963 film Dr. Strangelove about the United States surviving a Soviet nuclear strike even if “ten to twenty million” Americans were killed in the process was not a joke: Numerous real groups believed (or wanted to believe) that a nuclear war was winnable or at least survivable, even though we would “get our hair mussed” – just so long as those advocating this view didn’t get their particular hair mussed, of course.
In summation: Nuclear bombs dropped on people on Earth = bad, nuclear bombs used to push spaceship to Alpha Centauri = good. There are many technologies that can be subverted into a weapon.
Does this mean we abandon the progress our civilization has made just because the potential for danger is there? Lots of people get killed by guns and automobiles every year, with the latter polluting our environment and eating up Earth’s natural resources by the many millions, yet they remain with us and have advocacy groups which support their continued existence with a fervor bordering on cult behavior.
Part 2 of my response next.
Alex Tolley then said:
“Furthermore, I am unclear why this approach is so popular. Earlier posts on the Icarus fusion drive suggested that its use for solar system propulsion has a similar performance. So why go with a-bombs when a cleaner, non-proliferative approach is on the horizon? Perhaps that horizon is too far away for some, but I would rather we bring that one closer with R&D than assume that we must do Orion as the nearest term “viable” option.”
LJK replies:
While I would just love us to have some beautifully efficient, clean propulsion design for interstellar travel ala the USS Enterprise warp drive on Star Trek, the stark fact of reality is that just about every other plan for relatively fast (and even not-so-fast) starship propulsion involves technological and physics barriers that contain horizons so far off it is difficult to make even a vague prediction as to when we will see them.
Even fusion, perhaps among the least demanding of the proposals in this field, is still waiting for a working power plant model on Earth, forget as a spaceship drive. And controlled fusion is something that has been actively worked on for decades with a lot of funding, with the promise that it will be ready “within the next twenty years” for the last few two decades.
Then we come to the more advanced plans: Antimatter propulsion could get us to 99% light speed in theory, but ask me how much antimatter has been made in reality, how long it was contained, and how much even a little bit of it costs at present, and you will see why antimatter drives remain firmly in the SF camp.
The idea of beamed propulsion is also an appealing one and also technically conceivable, but for interstellar purposes we need powerful lasers stationed in space and sails hundreds of miles across. Plus, if you think nukes in space would cause fits, just wait until the populace finds out about that giant laser station over their heads.
Remember the Bussard ramjet? Now there was a beautiful design, using the very hydrogen atoms permeating the interstellar medium itself for fuel. The problems here are that the ramjet’s engines would utilize fusion (see above) and the scoop would have to be massive to collect enough space hydrogen. Even if you used a generated magnetic field for the scoop instead of a physical one, we are talking a lot of energy here, plus who knows what such a big magnetic field might do to the ship and any crew?
As for the concepts of actual warp drives, black holes, and cosmic wormholes, you know that outside of thinking about them, no one is doing any real research, or at least nothing that will get seriously funded any time soon. Plus in the case of actual ways to circumvent spacetime, that will require pure luck as much as anything else.
I for one do not want to sit around and hope that some day a wormhole will suddenly make itself available to us or that an ETI will stop by and offer humanity a warp drive system (and even if one did, we should have to wonder why an alien species is being so generous). Check out the Fred Rogers song “You’ve Got To Do It” to see what I mean here.
Now what I really want here is to be proven wrong on all these points, that ultimately relying on a bunch of nuclear bombs to get us into the rest of the galaxy will be as archaic as horse-drawn buggies are now for Earth transportation. However, while I am not an engineering expert, I have read enough on the subject of interstellar travel to know that Orion is still the most practical way of ever hoping to make it to another star system in under 77,000 years (which is how long it will take the Pioneers and Voyagers to get as far as the distance to Alpha Centauri – and the two Voyagers will stop transmitting circa 2025). Even the Icarus group is now advocating other methods of propulsion in addition to fusion and has asked other groups to form to pursue those ideas.
So until Zefram Cochrane comes along in about 2063, I am going to keep focusing and hoping on what I know we can do with what we have got now. And certainly I want people to keep looking into all those alternate propulsion plans, because I do not want to be lumped in with the guys who used to say that man will never fly heaver-than-air craft or go to the Moon some day.
Alex Tolley
“Furthermore, I am unclear why this approach is so popular. Earlier posts on the Icarus fusion drive suggested that its use for solar system propulsion has a similar performance. So why go with a-bombs when a cleaner, non-proliferative approach is on the horizon?”
It “is” on the horizon for 60 years.
Do not confuse biased predictions with reality.
At this point, a good argument can be made that efficient fusion reactors are not even feasible.
Pfft. When it comes to fusion, I’m firmly in the camp that advocates removing money from Tokamaks and trying other methods, because even if Tokamaks can be made to work, they’re not going to offer cheap energy, and they’ll be useless for propulsion.
When it comes to interstellar propulsion, I like the sound of RAIR, combined with very storable fusion fuel (Lithium, Boron etc) – but the, ahem, rarity of interstellar hydrogen makes it rather difficult. We may be able to use it for propulsion from, say, 20% of c to 60% of c, though? The interstellar ions could be directed straight into the plasma exhaust, ala VASIMR…
The use of plastics as fuel hasn’t been mentioned for fusion rockets yet… poly(dideuteroethene) might be a possible candidate only 25% of the mass will be fuel, yes, which will halve the Vex from a fully deuterium rocket, but that could still mean a respectable 0.03c, which given it’s storability (and higher thrust, since the carbon would be part of the exhaust) might allow flight speeds of around 10% of c. Of course, Deuterium or He3 stored in Lithium tanks…
I really can add to ljk on this
Just think these simple points
10 percent of light
Current Technology
1 trillion dollars
That is less the the 2008 China plus US Stimulus
I may have missed it in ljks comments but during the cold war we had bombers flying all over with nuclear weapons 24/7 . We are just going to be launching them up to fuel the Orion
Anyone want to build a pulsed high explosive demonstration rocket?
@ljk
Using existing nuclear weapons is one thing. How many flights would that be?
What I want is a space industry, which means that the ships and flights will be many. That will mean building more bombs and that is where the proliferation starts. Are you seriously suggesting that if a state can build bombs it won’t state that they are for peaceful, space exploration purposes?
I don’t think Orion is suitable for a trip to the stars, but the energy is clearly there for solar system exploration. Therefore to state that we have no alternatives in the near future is true, but their performance envelope only needs to be for the solar system. We don’t need to set up straw man arguments that require Orion now.
@Avatar2.0
Fusion reactors are not on the near horizon today. But fusion engines are different. Just like a-bombs are not nuclear reactors.
“Even fusion, perhaps among the least demanding of the proposals in this field, is still waiting for a working power plant model on Earth, forget as a spaceship drive. ”
Ironically, for essentially the same reason that we’re awaiting a nuclear space drive: Fear of nuclear bombs. Fusion doesn’t “want” to happen small scale and steady state, but we’ve been able to make it happen on moderate scale and not remotely steady state for better than half a century, reliably. Building a power plant based on nuclear bombs is actually less challenging than Orion, because you don’t have to worry about mass ratios. But it’s politically impossible for exactly the same reason.
I’m convinced that eventually somebody is going to do Orion, because it’s just so glaringly superior to every existing alternative. It may have to wait until we’ve already colonized space, and the people living there don’t have to worry about the phobias of grown huggers.
Alex Tolley
“Fusion reactors are not on the near horizon today. But fusion engines are different. Just like a-bombs are not nuclear reactors.”
It’s the other way around, Alex – fusion engines are HARDER to to than fusion reactors.
Unless you’re talking about fusion (thermonuclear) bombs – which is, essentially, Orion.
Building a fusion drive based on fusion bomblets, and capable of extracting energy from the plasma (ala fusion powerplant), doesn’t appear to be that difficult to build, especially in a vacuum. It would essentially be a pulsed fusion reactor. Add in some water to the exhaust to allow it to act like VASIMR – ah, “water down” the exhaust for higher thrust but lower Isp – and you’d have an ace interplanetary craft. How small can fusion bombs be made? But then you get yield issues…
Orion has a strange distant cousin.
Many may have heard of the Los Alamos/Livermore Project Plowshare.
Lots of different proposals of using fission and fusion ‘devices’ for peaceful purposes.
Most of them pretty harebrained:
http://en.wikipedia.org/wiki/Operation_Plowshare
This one could have really worked!
The Pacer project.
The idea was to explode , thermonuclear devices underground to general electricity.
The cheapest way I ever saw was to use salt domes (all over the world, number in the Southern Gulf Coast were proposed).
The most primitive was to explode a small ‘pulse unit’ in a dome with water, vaporize it, run a turbine, some estimates I saw was this could give one a 5 cent per kilowatt hour power generation.
So once again thermonuclear bombs could give one a build-it-tomorrow fusion power plant!
Other ideas here:
http://en.wikipedia.org/wiki/PACER_%28fusion%29
(That Wiki article needs some elaboration, the original papers are on the WEB, studies have even gone on to the present day.)
WELL. I won’t go into the political horror show this would generate , especially manufacturing a bunch of small thermonuclear devices.
I live in Texas and even we Red state-ers blanch at the thought of such a plant in our back yards. We have salt domes!
Thanks for the reply Tony P, concerning your idea, I take it you mean water ice as the barrier? Its a good question, water/ice is readily available but I thought that perhaps the mass would be the prohibitive factor.
Another question, with beamed propulsion I thought it would be more feasible for use it getting payloads into orbit, wouldn’t using this for of propulsion for an interplanetary or interstellar probe be to costly?
Also I thought that one of the advantages of the beamed propulsion is that the probe doesn’t carry its own fuel supply, how would the probe decelerate? Would it be solar sail or Bussard Ramjet with its breaking advantages?
Alex Tolley said on November 17, 2011 at 18:40:
“Using existing nuclear weapons is one thing. How many flights would that be? What I want is a space industry, which means that the ships and flights will be many. That will mean building more bombs and that is where the proliferation starts. Are you seriously suggesting that if a state can build bombs it won’t state that they are for peaceful, space exploration purposes?
“I don’t think Orion is suitable for a trip to the stars, but the energy is clearly there for solar system exploration. Therefore to state that we have no alternatives in the near future is true, but their performance envelope only needs to be for the solar system. We don’t need to set up straw man arguments that require Orion now.”
LJK replies:
I see Orion as a stepping stone for interstellar travel, not the final result forever. Just as the Mercury and Vostok spacecraft were our first efforts to place humans in the Final Frontier, not the end results. I like Orion mainly because it is feasible with current technology and has a fuel source that actually exists, along with the delicious irony of turning a deadly weapon into the means of expanding human society both physically and culturally. I do not foresee us using Orion forever to get around the galaxy, thus there will be no need to perpetually crank out nuclear bombs for it.
While I am naturally aware of the obvious dangers with nuclear weapons, I need to note again that since we have been able to produce these bombs since 1945, only two out of the many tens of thousands built since that time have been used in warfare. Clearly something more than just blind luck has been going on to keep these devices from reducing our civilization to rubble. Among them is the fact that nuclear bombs are not easy to make, otherwise you know North Korea, Iran, and probably a dozen other nations and groups would have had and used them by now.
I also see Orion as our early and relatively fast means of interstellar exploration because its method of propulsion is too big and powerful for Sol system use. Not saying it may not happen, but by the time Orion comes about we may have at least some colonies in the Inner Sol system and no doubt they will shout about a nuclear bomb powered spaceship in their vicinity. No, Orion is meant for bigger and farther things, namely the stars.
Brett Bellmore said on November 17, 2011 at 20:46:
“I’m convinced that eventually somebody is going to do Orion, because it’s just so glaringly superior to every existing alternative. It may have to wait until we’ve already colonized space, and the people living there don’t have to worry about the phobias of grown huggers.”
LJK replies:
So do I. And right now my money is on a certain nation with a big space program growing every day (they’ve got FIVE working space centers and are building a sixth), a sophisticated nuclear program since 1964, lots of people and resources to dip into, and – most importantly – a huge remote region far from most of their main population centers where they used to test their nuclear bombs and would be ideal for launching an Orion safely. Plus, the political issues which are brought up all the time about Orion’s propulsion method will probably be circumvented by this nation. I am not saying whether this is the right or nice thing to do, I am just making a political observation.
And yes, there is another nation just to the north of the one I mentioned that has many similar qualities for making Orion possible, including the interest, will, and lack of Western PCness, but whether they will ever have the funds and the ability to get their act together to make Orion a reality is another matter.
Of course one scenario I can see is someone or some group with enough money to spark their interest. I have said elsewhere in this blog that if humans ever do venture to the stars in person, the first ones to do so might be the equivalent of a cult wishing to leave the focus of human society and start a new life far, far away from the influence of others. And some of these groups have a lot of money and connections.
Those expecting NASA or some other national space agency to be the ones to make interstellar flight a reality need to simply look at the current state of things to know that our celestial neighbors the Moon, Mars, and the planetoids seem more out of reach any time soon than ever, to say nothing of Alpha Centauri.
Mass will always be a prohibitive factor, but at least water can be found in space, the moon, etc. For an ion engine, a massive ship would not work well together, but if you exert enough thrust with a sort of rocket or nuclear pulse drive, then mass would not be as big of a factor. Someone correct me if I’m wrong here.
As far as beamed propulsion, I don’t see how it would be all that useful for getting payloads to orbit. I normally associate beamed propulsion with hitting a target on a ship with a high powered beam like a laser, and it either uses the beamed energy like a sail or redirects the energy to generate electricity that in turn runs some sort of electric powered engine, like a ion engine. This sort of answers your second question. For deceleration, beamed energy would power engines pointing the other way, or power a Bussard type scoop to use its drag, to decelerate.
@TonyP
“As far as beamed propulsion, I don’t see how it would be all that useful for getting payloads to orbit. ”
There are ideas for use to LEO – using microwaves to heat H2 for a SSTO vehicle. The suggested performance improvement over existing vehicles is about 2:1. If it could be made to work with water as the propellant (hi tech steam rocket?) then you would have an extremely safe vehicle for lobbing payloads to orbit.
Microwave rocket
Also Lyrabo’s lightcraft concept that uses lasers and atmospheric air for most of the acceleration.
@ljk
“While I am naturally aware of the obvious dangers with nuclear weapons, I need to note again that since we have been able to produce these bombs since 1945, only two out of the many tens of thousands built since that time have been used in warfare. Clearly something more than just blind luck has been going on to keep these devices from reducing our civilization to rubble. Among them is the fact that nuclear bombs are not easy to make, otherwise you know North Korea, Iran, and probably a dozen other nations and groups would have had and used them by now. ”
Almost Panglossian thinking. The efforts to contain nuclear weapons proliferation have failed. A number of countries have the bomb, and a greater number are actively seeking to make them work, including N. Korea, Iran. And let me remind you that we came close to using them during the Cuban Missile Crisis and during the Reagan era (by error). More actors, with differing agendas will just make this worse.
You skipped my question about manufacture. One (or a few) Orion flights might use up the nuclear stockpile. Then what? If the concept was successful you would want to make more – so the weapon making program gears up – a nice job for the DoD with a nice excuse.
This is not rational.
I agree nuclear propulsion is needed for interplanetary flight as we currently envisage it, but this is not the way to go.
My bet is that miniaturization will be the key to interstellar slight, with in situ resource manufacture. Humans will probably not be shipped as meat bags to the stars with any conceivable real space technology. To the outer planets they may (I hope they do), but it won’t be with nuclear bombs exploded behind a massive pusher plate.
Hey, Candide! Huge Voltaire fan here.
In the end, does it really matter what I say or think on the subject here? I know what needs to be done to turn humanity into a really great species and society, but bigger and better people than me have tried with mixed results at best.
I hope that something more sophisticated and cleaner than Orion comes along. However, my fear is that it will be either fantasy or way off in the future. Even worse, the political winds and whims of the populace will render the whole thing null and void, so we can end up spending decade after decade arguing and wishing we could do starflight, if only…. Just like we’ve been talking about sending humans to Mars since the 1950s and probably would be doing the same about the Moon if not for that fluke situation in the 1960s.
I think I shall remain Panglossian, because the alternative is worse than a nuclear war: It is the stagnation of a race that could have reached the stars, but spent most of its time arguing about why it couldn’t and worrying about every little fear and whether it would be PC or not.
Or maybe I am just a victim of growing up in the era that thought we would have jetpacks, flying cars, laser pistols, household robots, and vacation trips to the Moon and Venus by The Year 2000 A.D.